Agilent 53150A Operations Guide

HP 53150A/151A/152A Microwave Frequency Counter

Operating Guide

This guide describes how to use the HP 53150A, 53151A, and 53152A Microwave Frequency Counters. The information in this guide applies to instruments having the number prefix listed below, unless accompanied

by a “Manual Updating Changes” package indicating otherwise.

SERIAL PREFIX NUMBER: 3735A and above (53150A)

3736A and above (53151A) 3737A and above (53152A)

HP 53150A/151A/152A Microwave Frequency Counter



Reproduction, adaptation, or translations without prior written permission is prohibited, except as allowed under the copyright laws.

Printed: May 1999 Printed in USA

Manual part number 53150-90001

Certification and Warranty

Certification

Hewlett-Packard Company certifies that this product met its published specification at the time of shipment from the factory. Hewlett-Packard further certifies that its calibration measurements are traceable to the United States National Institute of Standards and Technol ogy (formerly National Bureau of Standards), to the extent allowed by the

Institute’s calibration facility, and to the calibration facilities of other International Standards Organization members.

Warranty

HP warrants HP hardware, accessories and supplies against defects in materials and workmanship for a period of one year from date of shipment. If HP receives notice of such defects during the warranty period, HP will, at its option, either repair or replace products which prove to be defective. Replacement products may be either new or like-new.

HP warrants that HP software will not fail to execute its programming instructions, for the period specified above, due to defects in material and workmanship when properly installed and used. If HP receives notice of such defects during the warranty period, HP will replace software media which does not execute its programming instructions due to such defects.

For detailed warra nty information, see back matter.

Safety Considerations General

This product and related documentation must be reviewed for familiarizat ion with this safety marki ngs and instructions before operation.

Before Cleaning

Disconnect the product from operating power before cleaning.

Warning Symbols That May Be Used In This Book

Instruction manual symbol; the product will be marked with this symbol when it is necessary for the user to refer to the instruction manual.

Indicates hazardous voltages.

Indicates earth (ground) terminal.

Indicates terminal is connected to chassis when such connection is not apparent.

Indicates Alternating current.

Indicates Direct current.

Safety Considerations (contd)

WARNING

BODILY INJUR Y OR DEATH MAY RESULT FROM FAILURE TO HEED A WARNING. DO NOT PROCEED BEYOND A WARNING UNTIL THE INDICATED CONDITIONS ARE FULLY UNDERSTOOD AND MET .

CAUTION

Damage to equipment, or incorrect measurement data, may result from failure to heed a caution. Do not proceed beyond a CAUTION until the indicated conditions are fully understood and met.

Safety Earth Ground

An uninterruptible safety earth ground must be maintained from the mains power source to the product’s ground circuitry.

WARNING

WHEN MEASURING POWER LINE SIGNALS, BE EXTREMELY CAREFUL AND ALWAYS USE A STEP-DOWN ISOLATION TRANSFORMER WHICH OUTPUT IS COMPATIBLE WITH THE INPUT MEASUREMENT CAPABILITIES OF THIS

PRODUCT. THIS PRODUCT’S FRONT AND REAR PANELS ARE TYPCIALLY AT EARTH GROUND.

TO MEASURE AC POWER LINE SIGNALS WITHOUT AN ISOLATION TRANSFORMER.

For additional safety and acoustic noise information, see back matter.

THUS, NEVER TRY

Hewlett-Packard Company 8.NC.NL.A.11.03.97.R1.P.CW1C3NC Santa Clara Division 5301 Stevens Creek Boulevard Santa Clara, California 95052-8059

Contents

In This Guide

Operating Guide Contents and Organization x Related Documents xi Types of Service Available

if Your Instrument Fails xii

Standard Repair Services (Worldwide) xii Express Repair/Performance Calibration

Service (USA Only) xii Repair Instrument Yourself xii

Repackaging for Shipment xiii Description of the Microwave Frequency Counter xiv Options xv

Hardware xv Support xv

Accessories Supplied and Available xvi

Accessories Supplied xvi Accessories Available xvi Manuals Supplied xvi

HP 53150A/151A/152A Quick Reference Guide xvii

1 Getting Started

The Front Panel at a Glance 1-2 The Front Panel Indicators at a Glance 1-3 The Front Panel Menus at a Glance 1-4 The Display Annunciators at a Glance 1-5 The Display Special Characters at a Glance 1-6 The Rear Panel at a Glance 1-7

Operating Guide iii

Contents

Operating the Counter 1-8

Turning the Counter On 1-10 Turning the Display Backlight Off or On 1-11 Using the Menu 1-12

Displaying the Menu 1-12 Navigating in the Menu and Changing Settings 1-12 Setting the Serial Port Baud Rate (Menu Example) 1-15

Selecting the Input Channel 1-16 Measuring Frequency 1-17 Measuring Relative Frequency 1-19 Offsetting a Frequency Measurement 1-20 Measuring Power (Channel 2 Only) 1-22 Selecting the Unit of Measurement for Power 1-23 Measuring Relative Power 1-24 Offsetting a Power Measurement 1-24 Using Power Correction 1-28

Selecting a Power-Correction Profile 1-28 Entering Data Points in a Power-Correction

Profile 1-28 Setting the Measurement Rate 1-32 Setting the Number of Averages 1-33 Setting the Resolution 1-34

2 Operating Your Frequency Counter

Introduction 2-2

Chapter Summary 2-2

How this Counter Wor k s for You 2-3 Summary of the Measurement Sequence 2-4 Using the Selection Keys 2-5

Sequencing Through the Menu 2-5 Numeric Entry 2-6 Changing States 2-7

iv Operating Guide

Contents

Using the Clear and Reset/Local Keys 2-9

Acknowledging Messages 2-9

Other Function Selection Keys 2-10 Measuring Frequency 2-12 Setting the Resolution

and the Measurement Rate 2-14

Setting the Resolution 2-14

Resolution Setting Example 2-15

Setting the Measurement Rate 2-16

Rate Setting Example 2-16

Setting the Number of Averages 2-17

Averages Setting Example 2-17

Measuring Relative Frequency 2-20

Relative Frequency Example 2-20

Offsetting a Frequency Measurement 2-21

Frequency Offset Example 2-21

Measuring Power 2-24

Power Measurement Example 2-24

Measuring Relative Power 2-26

Relative Power Example 2-26

Offsetting a Power Measurement 2-27

Power Offset Example 2-27

Using Power Correction 2-30

Power Correction Example: Selecting a Correction Profile 2-33

Power Correction Example: Editing Data Point Values 2-35

Using the Menu 2-39

Navigating in the Menu and Changing Settings 2-41 Reference Oscillator (REF OSC)2-42 Do Self Test 2-43 Battery Voltage (BATT VOLTAGE)2-43 Operating Hours (OP HOURS)2-43

Operating Guide v

Contents

Model Number, Firmware Version,

Serial Number, and Option Codes 2-44

Preset 2-45

RS-232 Serial Port Data Rate (BAUD)2-46

Frequency Modulation (FM)2-46

Channel 1 Low-Pass Filter (CH1 LPF)2-46

Recall User Settings (RECALL)2-46

Save User Setti n gs (SAVE)2-46

Power Correction (PWR CORR)2-46

3 Specifications

Introduction 3-2

A Rack Mounting the Counter

Rack Mounting the Counter A-2

B Messages

Overview B-2 Status Messages B-2 Self-Test Messages B-3 Error Messages B-4

C Using the Battery Option

Overview C-2 Operating the Counter from the Batteries C-2 Operating the Counter

from a DC Power Source C-3 Replacing the Batteries C-4

Removing the Batteries C-4 Installing Batteries C-5

vi Operating Guide

Index

Contents

Charging the Batteries C-8 Precautions C-9

Operating Guide vii

Contents

viii Operating Guide

In This Guide

This book is the operating guide for the HP 53150A (20 GHz), 53151A (26.5 GHz), and 53152A (46 GHz) Frequency Counters. It consists of a table of contents, this preface, a quick reference guide, three chapters, three appendices, and an index.

This preface contains the following information:

• Operating Guide Contents and Organization pg. x

• Related Documents pg. xi

• Types of Service Available if Your Instrument Fails pg. xii

• Repackaging for Shipment pg. xiii

• Description of the Microwave Frequency Counter pg. xiv

• Options pg. xv

• Accessories Supplied and Available pg. xvi

• Manuals Supplied pg. xvi

Operating Guide ix

In This Guide

Operating Guide Contents and Organization

Table of Contents. The Quick Reference Guide consists of a Menu Tree (tear-out sheet)

that serves as a tool to trigger your memory or get you quickly reacquainted with the instrument.

Chapter 1 (Getting Started ) is a quick-start guide that gives you a brief overview of the Counter’s keys, indicators, menus, display, and connectors. A graphical procedure for performing a measurement is also provided.

Chapter 2 (Operating Your Frequency Counter) is an operator’s reference. You are given an overview of each group of front-panel keys, operating functions, and menus followed by a series of exercises that guide you through the operation of the Counter.

Chapter 3 (Specifications) lists the specifications and characteristics of the Counter.

Appendix A (Rack Mounting the Counter) provides rack-mounting procedures for the Counter.

Appendix B (Messages) lists and explains all of the messages that are

displayed on the Counter’s front panel and/or sent over the RS-232 serial interface.

Appendix C (U sing the Battery Option) explains how to use the Counter with the Battery option.

Index

x Operating Guide

In This Guide

Types of Service Available if Your Instrument Fails

If your Counter fails within one year of original purchase, HP will repair it free of charge. If your instrument fails after your one-year warranty expires, HP will repair it, or you can repair it yourself.

There are three types of repair services:

• Standard repair service—if downtime is not critical.

• Express Repair/Performance Calibration Service—if downtime is

critical.

• Owner repair—repair the unit yourself using usin g the Assembly-L evel Service Guide.

Standard Repair Services (Worldwide)

Contact your nearest HP Service Center to arrange to have your Counter repaired.

Express Repair/Performance Calibration Service (USA Only)

If downtime is critical, you can receive your repaired Counter via overnight shipment. Just call 1-800-403-0801 and ask for Express Repair/Performance Calibration Service. When your Counter is repaired, it is returned via overnight shipment.

Repair Instrument Yourself

If you choose to repair the instrument yourself or would like more details on self test and calibration, use the procedures in the Assembly-Level Service Guide.

xii Operating Guide

In This Guide

Repackaging for Shipment

For the Express Repair/Performance Calibration Service described above, return your failed Counter to the designated HP Service Center, using the

instrument’s original shipping carton (if available). HP notifies you when your failed instrument is received.

If the instrument is to be shipped to HP for service or repair, be sure you do the following:

• Attach a tag to the instrument identifying the owner and indicating the required service or repair. Include the instrument model number and full serial number.

• Place the instrument in its original container (if available) with appropriate packaging material.

• Secure the container with strong tape or shipping bands.

If the original shipping container is not available, place your unit in a container with at least 4 inches of compressible packaging material around all sides of the unit. Use static free packaging materials to avoid additional damage to your unit.

HP suggests that you always insure shipments.

Operating Guide xiii

In This Guide

Description of the Microwave Fre quency Counter

The HP 53150A, 53151A, and 53152A Microwave Frequency Counters are capable of measuring frequencies from 10Hz to 125 MHz on Channel 1 and from 50 MHz to 20 GHz (53150A), 26.5 GHz (53151A), and 46 GHz (53152A) on Channel 2. These frequency counters are also capable of measuring power on Channel 2 (in the same frequency ranges). All three Counters have a maximum frequency resolution of 1 Hz.

The HP 53150A/151A/152A Counter provides HP-IB and RS-232 serial interfaces and are suitable for bench-top and ATE operation.

The basic measurement functions of the HP 53150A/151A/152A Counter includes Frequency, Relative Frequency, Frequency Offset, and Power (including Power Offset and Relativ e Power). All of these features are accessible from the front panel and over the HP-IB and RS-232 interfaces.

The HP 53150A/151A/152A Counter includes the following additional measurement functions and features that are designed specifically for manufacturing and service applications:

• 1, 2, 5, and 10 MHz external reference capability

• Optional high-stability oven oscillator for high-accuracy needs and

lengthened calibration cycles

• Frequency and power offset capabilities for relative measurements

• SCPI programming capability

Programmable control is performed via an HP-IB or an RS-232 serial interface. The HP-IB and RS-232C ports are standard for the HP 53150A/151A/152A.

xiv Operating Guide

In This Guide

Options

The options available for the HP 53150A/151A/152A Microwave Frequency Counter are listed following this paragraph. Specifications for

the options are listed in Chapter 3, “Specifications.” Options ordered with the Counter are installed at the factory and are ready for operation on delivery. Refer to the "Retrofitting Options" chapter in the HP 53150A/151A/152A Assembly-Level Service Guide for information on installing options in the field.

Hardware

• High Stability Oven Timebase, Option 001

• Battery/DC Power Input, Option 002

• Rack Mount Kit, Option 1CM

Support

• 3-year Return to HP for Repair, Option W30

• 3-year Return to HP for Calibration, Option W32

• 3-year Return to HP for Standards Compliant Calibration,

Option W34

• 5-year Return to HP for Repair, Option W50

• 5-year Return to HP for Calibration, Option W52

• 5-year Return to HP for Standards Compliant Calibration,

Option W52

Operating Guide xv

In This Guide

Accessories Supplied and Available

Accessories Supplied

• Power cord, 2.3 meters (Part number dependent upon destination country.)

Accessories Available

• Automotive Power Adapter (HP P/N 53150-60214)

• Battery (HP P/N 53150-80010)

• Battery Charger (HP P/N 53150-60217)

(Includes Automotive Power Adapter)

• HP-IB Cables (HP P/N 10833A/B/C/D)

• RS-232 Cable (HP P/N 53150-60215)

Manuals Supplied

HP 53150A/151A/152A Operating Guide—this guide (HP P/N 53150-90001)

HP 53150A/151A/152A Programming Guide

(HP P/N 53150-90002)

HP 53150A/151A/152A Assembly-Level Service Guide

(HP P/N 53150-90003)

xvi Operating Guide

HP 53150A/151A/152A Quick Reference Guide

The Quick Reference Guide is designed for experienced users of the HP 53150A/151A/151A/152A Frequency Counter. It is intended to be used as a tool to trigger your memory. If you are using the Counter for the first time,

HP recommends that you at least read Chapter 1, “Getting Started,” first.

The Quick Reference Guide, which follows this page, consists of a menu tree that may be torn out of the guide for external use.

Reference

Quick

xvii

Quick

Reference

xviii

HP 53150A/151A/152A

Frequency Counter

On/Off

+/-Clear

Reset/ Local

REF OSC > INT

REF OSC > EXT

PRESET

Reference

Quick

SAVE > 0 to 9 RECALL > 0 to 9

CH1 LPF > OFF

CH1 LPF > ON

FM > AUTO

FM > OFF

BAUD > 9600

BAUD > 4800 BAUD > 2400 BAUD > 1200 BAUD > 19200 BAUD > 14400

HP 53150A > OP 9999 HRS BATT VOLTAGE

0.0

DO SELF TEST

PWR CORR > OFF

PWR CORR > 0

PWR CORR > 9

< 00-111-222 >

Freq Offset

Rate

00 000 000 000 000 49 999 999 999 999 ± 99.99

Freq Offset

Rate

RATE FAST

RATE MED

< SN 999999 >

AVERAGES 01

AVERAGES 99 RATE SLOW RATE HOLD

Pwr Offset

Avg

± 00.00

Pwr Offset

Avg

HPIB

Resol

± 00.00

HPIB ADDR > 0 HPIB ADDR > 30

HPIB

Resol

RESOL 1 HZ

RESOL 10 KHZ RESOL 100 KHZ RESOL 1 MHZ

QR-1

Quick

Reference

QR-2

Getting Started

1342

Chapter 1 Getting Started

The Front Panel at a Glance

53150A

POWER

Standby

Reset/ Local

Shift

Freq Offset

Rate

On/Off

Clear

Ch 12

Rel Freq

Offset

Avg On

Rel Pwr

Offset

GHz MHz kHz Hz

dB dBm Watts mW uW %

MODIFY

Pwr Offset

Avg

+/-

HPIB Resol

Enter

1 Standby indicator 2 Power/Standby switch 3 LCD display 4 Channel 1 input connector 5 Channel 2 input connector 6 Display Power / dBm/W key (Channel 2) 7 Offset On/Off / Relative Power key

(Channel 2)

Channel Selection key

8 9 Offset On/Off / Relative Frequency key

11 Selection keys active indicator 12 Selection (arrow) keys 13 Resolution / HPIB key 14 Enter key 15 Average / Power Offset key 16 Sign (+/–) key 17 Rate / Frequency Offset key 18 Clear / Backlight On/Off ke y 19 Reset/Local / Menu key 20 Shift key

20 GHz Counter

Ext Rel

Hold

Rate Rmt SRQ Error

Shift

FREQ

Chan Select

Rel Freq Rel Pwr Offset

On/Off

POWER

Channel 2 50 MHz to 20 GHz

Gate

dBm/ W Display

Power

Offset On/Off

CHANNEL 1

10 Hz to 125 MHz

1M W

DAMAGE

+30 dBm

CHANNEL 2

DAMAGE

+27 dBm

5678912 1013 11141516171819

50 W

10 Gate indicator

1-2 Operating Guide

Chapter 1 Getting Started

The Front Panel Indicators at a Glance

The front panel includes three LED indicators. These are listed and described in the following table.

Indicator Description

The Standby indicator is lit whenever the

POWER

Standby

Main ~ Power switch on the rear panel is turned ON, and the POWER switch on the front panel is OFF

(out). During Standby, most of the instrument’s circuits do not receive power. However, the timebase and the cooling fan are powered so that the temperature in the timebase components remains stable, and if the Battery option is installed, the battery-charging circuits a re powered. When you press the POWER switch on the front panel, the Standby indicator goes off, and all of the Counter’s circuits receive power.

NOTE

When the LED indicator between the arrow keys flashes, the arrow keys can be used to navigate and change values in menus.

When you make a change in a menu, always press the Enter key to save the setting and exit the menu.

The Gate LED indicator flashes to indicate the rate

FREQ

Chan Select

Gate

at which measurements are triggered. The flash rate of the LED varies with the settings of the measurement rate (Rate key) and the measurement resolution (Resol key). The flash rate of th e LED provides a rough indication of the number of measurements th at are being tak en in a given per iod of time.

It is normal for the fan in the Counter to run when the Counter is in Standby mode. Power is supplied to the timebase whenever the Main ~ Power switch is on to maintain long term measurement reliability, and the fan helps maintain timebase temperature stability.

Operating Guide 1-3

Chapter 1 Getting Started

The Front Panel Menus at a Glance

Shift

Reset/ Local

REF OSC > INT

REF OSC > EXT

SAVE > 0 to 9

RECALL > 0 to 9

PRESET

HP 53150A >

OP 9999 HRS

< 00-111-222 >

< SN 999999 >

CH1 LPF > OFF

CH1 LPF > ON

FM > AUTO

FM > OFF

BAUD > 9600

BAUD > 4800 BAUD > 2400 BAUD > 1200 BAUD > 19200 BAUD > 14400

Rate

RATE FAST

RATE MED RATE SLOW

RATE HOLD

BATT VOLTAGE

0.0

DO SELF TEST

PWR CORR > OFF

PWR CORR > 0

PWR CORR > 9

Avg

AVERAGES 01

AVERAGES 99

Resol

RESOL 1 HZ

RESOL 10 KHZ RESOL 100 KHZ RESOL 1 MHZ

Shift

HPIB

Resol

HPIB ADDR 0

HPIB ADDR 30

1-4 Operating Guide

Ch 12

Rel Freq

Offset

Avg On

Rel Pwr

Offset

Chapter 1 Getting Started

The Display Annunciators at a Glance

GHz MHz kHz Hz

dB dBm Watts mW uW %

Ext Rel

Hold

Rate Rmt SRQ Error

Shift

Annunciator Description

Ch 1 or Ch 2 Indi c at es w hich channel is selected t o m eas ur e an input signal. Freq I ndi c at es t hat the value displayed is a f req ue ncy reading. Rel Freq The displayed frequency value is relative to a previo us ly zer oe d val ue. Freq

Offset Avg On The displayed frequen cy val ue is the result of a number of indi vi du al frequency

Pwr The Counter is set to measure Power (Channel 2 only). Rel Pwr The displayed power measurement is relative to a previously zeroed power value. Pwr

Offset dB, dBm, W,

µW, %

mW,

Ext Ref The Counter is using an external refer ence signal for frequenc y m easurements. Hold Indicates the Counter is in Hold (single- measurement) mode. Rmt, SRQ Shows the current state of the HP-IB interface

Error Indicates that a front-pane l key command is unacceptab le in the cur r ent context. Shift Indicates that all front-panel keys are redefined to the func t io n pr in ted above the key.

The displayed frequency value is offset by a previously entered frequency value.

measurements that have been averaged.

The displayed power v alue i s offset by a p rev i ously entered power val ue.

Indicates the unit of m easurement for the cu rrently displayed p ow er value.

Provides a real-time ana lo g re pr esentation of the Power meas ur em ent (intended for peaking and similar procedures).

(Rmt = Remote operation via H P- I B; SRQ = Ser vice ReQuest).

Shows the amount of charge in the batteries (if the Battery option is installed).

Operating Guide 1-5

Chapter 1 Getting Started

The Display Special Characters at a Glance

Special Characters

NOTE

The first two special characters shown above are intended to help y ou navigate within the Menu. When the right pointer ( ) is flashing, it indicates the current setting for the selected Menu option. When the left pointer ( ) is flashing, it indicates that you can use the selection (arrow) keys to change the setting for the current Menu option.

Description

Points to the current value for a Menu setting.

Indicates that the value for the current Menu setting can be changed using the selection (arrow) key s.

When the letter “c” is displayed in the hundredths position of the power display, Power Correction mode is in effect.

1-6 Operating Guide

Chapter 1 Getting Started

The Rear Panel at a Glance

Main ~ Power

10 9 7

2 43 6

Reference 10 MHz

11 TO 18 VDC

EXT DC

Auxillary

In or Out

RS-232

1 AC Input/Power module (Senses

incoming voltage and adjusts automatically)

2 External Reference connector (BNC)

1, 2, 5, or 10 MHz Input 10 MHz Output

3 Fuse Holder (behind door) 4 Auxiliary connector (not populated)*

Made in U.S.A.

with domestic and foreign content

OPTIONS

001 Oven Time Base 002 Battery

WARNING:

To avold electric shock, do not remove covers.

No user-serviceable parts inside. Refer all servicing to qualified personnel.

This unit must be earth grounded.

AC POWER 100 – 130 VAC, 50/60/400 Hz 75 VA 220 – 240 VAC, 50/60 Hz 75 VA 250 V

5 Battery compartment (optional) or cover plate 6 HP-IB (IEEE-488.1) Interface connector 7 RS-232 Interface connector (RJ12) 8 Main AC Power On indicator 9 EXT DC power-input connector (functional only

when Battery option is installed)

10 Main ~ Power switch

ISM 1-A

FUSE

1.0 A T

* The Auxiliary connector is not installed on standard production units.

Operating Guide 1-7

Chapter 1 Getting Started

Operating the Counter

The procedures in this section are designed to familiarize you with the

Frequency Counter’s features and controls. HP suggests that you follow the steps for each of the se pro cedure s, e ven i f y ou d o not pres ent ly ne ed to make any measurements or to adjust any of the Counter’s settings. The following procedures are provided:

• Turning the Counter On

• Turning the Display Backlight Off or On

• Selecting an Input Channel

• Using the Menu

• Setting the Serial Port Baud Rate

• Measuring Frequency

• Measuring Relative Frequency

• Offsetting a Frequency Measurement

• Measuring Power

• Measuring Relative Power

• Offsetting a Power Measurement

• Using Power Correction

• Setting the Measurement Rate

• Setting the Number of Averages

• Setting the Resolution

1-8 Operating Guide

Chapter 1 Getting Started

Operating the Counter

The following legend defines the meanings of the icons used throughout this chapter.

Legend

Press key one time and release

Multiple key presses

Result

Auto operation

Connect signal

Disconnect signal

798

Indicator off

Indicator on

Indicator flashing

Operating Guide 1-9

Chapter 1 Getting Started

Operating the Counter

Turning the Counter On

To turn on the Counter, turn on the Main ~ Power switch on the rear panel (see page 1-7), and then press and re lease t he PO WER button on the front panel.

POWER

Standby

Ch 12

Rel Freq

Offset

Avg On

Rel Pwr

Offset

Ext Rel

dB dBm Watts mW uW %

Hold

Rate Rmt SRQ Error

Shift

Ch 2

Freq

1-10 Operating Guide

Chapter 1 Getting Started

Operating the Counter

NOTE

If a signal was applied to the Channel 2 input connector prior to turning on the Counter, CH2 N O SIG NAL is displayed momentarily. As soon as the

Counter acquires the input signal, it displays the signal’s value.

The internal Reference Oscillator requires 10 to 15 minutes to reach a stable operating temperature. Since the Reference Oscillator receives power only when the Counte r i s o n or in Sta ndb y mode , no mea surements should be taken unless the Counter’s Main ~ Pow er switch has been in the on (1) position for at least that amount of time.

Turning the Display Backlight Off or On

When you first turn the Counter on, the backlight for the LCD display is always lit. You can toggle the backlight off and on by pressing the Shift key and then the On/Off (Clear) key, as shown below.

Ch 2

Shift

On/Off

Clear

Freq

Ch 2

Freq

Shift

NOTE

Ch 2

Shift

On/Off

Clear

Freq

Ch 2

Freq

Shift

If your Counter has the Battery option, you can extend the length of time the Counter can operate from the batteries by turning off the display backlight.

Operating Guide 1-11

Chapter 1 Getting Started

Operating the Counter

Using the Menu

The HP 53150A/151A/152A Counter has one menu that you use to control

a number of the Counter’s features and functions.

Displaying the Menu

To display the Menu, press the Shift key and then the Menu (Reset/Local) key, as shown below.

Ch 2

Shift

Freq

Reset/ Local

Shift

Navigating in the Menu and Changing Settings

Use the Selection (arrow) keys to navigate to the setting you want to change and then to actually make the changes. For example, the diagram on the next page shows how to change the setting of the Reference Oscillator from INTernal to EXTernal. (In this example, a reference signal is applied to the External Reference connector, but no signal is applied to the Channel 2 input.)

NOTE

The Counter will not switch to EXTernal unless a suitable reference signal is available at the External Reference connector.

1-12 Operating Guide

Chapter 1 Getting Started

Operating the Counter

Shift

Reset/ Local

Ch 2

Freq

Shift

Enter

Ch 2

Ext Ref

When you select the Menu, the indicator between the arrow keys flashes to indicate that the arrow keys are now active. Since the Reference Oscillator setting is the first one displayed when you invoke the Menu

(unless you’ve used the Menu to change another setting since you turned the Counter on), you don’t have to use the (up-arrow) key or the (down-arrow) key to get to it.

Operating Guide 1-13

Chapter 1 Getting Started

Operating the Counter

When you press the (rig ht-arro w) ke y, the flashing annunciator ( ) changes direction, and the current setting for the Reference Oscillator (INT [internal] or EXT [ext ernal]) flashes . This indicat es that you can no w change this setting. Use ei ther the up-arrow key o r the down-arrow key to change the setting.

Press either the Enter key or the left arrow key to accept the currently displayed setting. The Enter key accepts the setting and exits the Menu; the left arrow key accepts the setting but does not exit the Menu. Use the left arrow key to accept a setting if you want to change additional menu settings. The Clear key reverses an unaccepted setting change.

You navigate to and adjust the remaining settings available in the Menu in the manner described above. The Menu also contains some items that provide information only (no settings are required [or possible] for these), such as Battery Voltage, Operation Hours, and information that identifies the Counter (HP model number, firmware version number, serial number, and installed option codes). These menu options and the ones described

below are shown in “The Front Panel Menus at a Glance” on page 1-4. There is also a menu item called Preset and one called Do Self Test. If you

press the Enter key while PRESET is displayed, all of the Counter’s settings are returned to the factory-default settings. If you press Enter while DO SELF TEST is displayed, the Co unter repeats the tests that are normally performed when the Counter is first turned on.

NOTE

Remember to terminate each value you change in any of the menu options by pressing the any menu option while the Menu is displayed by pressing the key or the

Enter key or the left arrow key. You can abort a change to

Reset/Local

Clear key. Both keys nullify any changes you made to the

current menu option, but they do not affect any changes to other menu options. The

Reset/Local key does not.

Clear key terminates the current menu session, but the

1-14 Operating Guide

Chapter 1 Getting Started

Operating the Counter

Setting the Serial Por t Baud Rate (Menu Example)

Ch 2

Shift

Reset/ Local

Freq

Shift

Ch 2

Enter

Freq

Operating Guide 1-15

Chapter 1 Getting Started

Operating the Counter

Selecting the Input Channel

You can toggle between Channels 1 and 2 by pressing the Chan Select key.

Ch 1

Chan Select

Chan

Select

Freq

Ch 2

Freq

1-16 Operating Guide

Chapter 1 Getting Started

Operating the Counter

Measuring Frequency

The following diagram shows the basic sequence to use to make a frequency measurement using Channel 1. This example assumes that the Counter is on and has completed the Self Test. For the purposes of this

example, use the 10 MHz reference output on the Counter’s rear panel as a signal source for input to Channel 1.

Ch 2

Freq

CHANNEL 1

10 Hz to 125 MHz

DAMAGE

+30 dBm

Chan Select

1M W

Ch 2

Freq

Ch 1

Freq

Ch 1

Freq

The same procedure applies to making a basic frequenc y meas urement o n Channel 2. However, since Channel 2 is automatically selected when you turn on the Counter, the channel-select ion step is unnecess ary (unless you previously selected Channel 1).

CAUTION The Channel 2 input path circuits contain sensitive GaAs semiconductors.

To prevent damage to these components, always adhere to standard ES D (Electro-Static Discharge) prevention procedures, and ensure that the maximum power specification for this channel (+27 dBm) is not exceeded.

Operating Guide 1-17

Chapter 1 Getting Started

Operating the Counter

NOTES

•

The Counter displays CH2 NO SIGNAL or CH1 NO SIGNAL and shuts down all unnecessary circuits when a signal of insufficient amplitude (or no signal) is applied to the corresponding input. This extends the reliability of the affected components, and if the Battery option is installed, extends the length of time the Counter can operate from the batteries.

•

When the frequency of a signal applied to the Channel 2 input exceeds the maximum rated frequency for the instrument, the Counter displays CH2 TOO HIGH.

CAUTION The 2.9 mm Planar Crown* connector used for the Channel 2 input on the

HP 53152A must be handled with care to prevent damage and/or contamination, especially since it acts as a wave guide as well as an electrical connection. Observe the following precautions when handling this connector:

1. If you remove the outer portion of the connector, do not touch the

exposed surfaces of either part of the connector with your bare skin or any material that is not intended for cleaning this type of connector.

2. Avoid dropping or striking either portion of the connector. If the connector becomes contaminated, it can be cleaned with isopropyl

alcohol and a lint-free cloth or other suitable cleaning implement.

Planar Crown® is a registered trademark of Weinschel Corp.

1-18 Operating Guide

Chapter 1 Getting Started

Operating the Counter

Measuring Relative Frequency

You can measure the difference in frequency from one measurement to another (drift) using the Relative Frequency function. You do this by pressing the Shift and Rel Freq (Offset On/Off) keys as shown in the diagram below (this example assumes that a signal is currently applied to Channel 1).

The Counter stores the current frequency reading when you press the Rel Freq key. It then subtracts this value from all subsequent readings and displays the difference until you press the Rel Freq key again.

Ch 1

Freq

Ch 1

Shift

Freq

Shift

NOTE

Rel Freq

Offset On/Off

Ch 1

Rel Freq

If the input signal fluctu a te s, th e va lue displayed varies as th e Coun t er continues to take measurements. You can vary the speed at which measurements are taken by varying the settings for Rate and Resolution

(see “Setting the Measurement Rate” and “Setting the Resolution” on pages 1-32 and 1-34).

Operating Guide 1-19

Chapter 1 Getting Started

Operating the Counter

Offsetting a Frequency Measurement

You can use the Frequency Offset (Freq Offset) function to add or subtract a constant value to/from a frequency measurement. For example, you can use an offset to compensate for a systematic error or to display the difference in frequency between two signals.

NOTE

The Frequency Offset and Relative Frequency functions can be used simultaneously.

To display an offset frequen cy measurement, you need to set the valu e and sign (+/–) of the offset and to turn the Frequency Offset function on. In the diagram on the next page, th e Frequency Offset function is enabled first,

and the offset value i s then e ntered. H owever, t he order do esn’t ma tter, s o you can also enter the offset value first, and then turn the offset function on.

When you are entering a value f or Frequen cy Offse t (or Power Offs et), yo u can use the Reset key to restore all of the displayed digits to zero. These are the only two functions in which the Reset key has this effect.

1-20 Operating Guide

Chapter 1 Getting Started

Operating the Counter

Offset On/Off

Shift

Freq Offset

Rate

Ch 2

Freq

Ch 2

Freq

Offset

Ch 2

Freq

Offset

Freq

Offset

Shift

Freq

Offset

+/-

Enter

Freq

Offset

Ch 2

Freq

Offset

Operating Guide 1-21

Chapter 1 Getting Started

Operating the Counter

Measuring Power (Channel 2 Only)

The HP 53150A/151A/152A Counter can measure signal power (in the same frequency ranges as for frequency measurements) on Channel 2. The example procedure for measuring power in the fo llowing diagram assumes that the Counter has previously been set up to measure a 25 GHz input on Channel 2.

NOTE

When the power of a signal applied to the Channel 2 input exceeds the maximum rated power for the instrument, the Counter displays HI.

CAUTION The Channel 2 input path circuits contain sensitive GaAs semiconductors.

To prevent damage to these components, always adhere to standard ESD (Electro-Static Discharge) prevention procedures, and ensure that the maximum power specification for this channel (+27 dBm) is not exceeded.

Ch 2

Freq

Ch 2

Display Power

Freq

Pwr

dBm

1-22 Operating Guide

Chapter 1 Getting Started

Operating the Counter

Selecting the Unit of Measurement for Power

The Counter’s power-measurement function can d isplay values in either of two sets of units of measurement—dB and dBm or W, mW, and µW (the Counter automatically selects the most ap prop riat e unit whe n eith er set of units is selected). Use the procedure in the following diagram to select the unit of measurement for power (this procedure assumes that a signal is currently applied on Channel 2 and that power is being displayed):

Ch 2

Shift

Freq

Pwr

Ch 2

Freq

Pwr

dBm

Shift

NOTE

dBm/W

Display Power

The Counter is specified for signals having amplitudes of up to +7.00 dBm.

Ch 2

Freq

Pwr

If a signal having an amplitude greater than +10.50 dBm is applied, and power measurement is enabled, the annunciators for the power reading display “HI” to indicate that the signal’s amplitude exceeds the specification. If a signal having an amplitude of less than –40.00 dBm is applied, the power annunciators display “LO” to indicate that the signal level is too low to be measured by this instrument.

CAUTION The Channel 2 input path circuits contain sensitive GaAs semiconductors.

Operating Guide 1-23

Chapter 1 Getting Started

Operating the Counter

Measuring Relative Power

You can measure the difference in power from one measurement to another (drift) using the Relative Power function. You do this by pressing the Shift an d Rel Pwr (Offset On/Off) keys, as shown in the diagram below (this example assumes that a signal is currently applied to Channel 2).

The Counter stores the current po wer reading wh en you press the Rel Pwr key. It then subtracts this value from all subsequent readings and displays the difference until you press the Rel Pwr key again.

Ch 2

Shift

Freq

Pwr

Ch 2

Freq

Pwr

dBm

Shift

NOTE

Rel Pwr Offset

On/Off

Ch 2

Freq

Rel Pwr

dBm

Offsetting a Power Measurement

The Power Offset and Relative Power functions can be used simultaneously.

To display an offset power measurement, you need to set the value and sign (+/–) of the offset and to turn the Power Offset function on. In the

1-24 Operating Guide

Chapter 1 Getting Started

Operating the Counter

following diagram, the Power Offset function is enabled first, and the

offset value is then entered . Howeve r, the order doesn’t matter, so you ca n also enter the offset value first, and then turn the offset function on.

Ch 2

Freq

Pwr

dBm

Rel Pwr

Offset On/Off

Shift

Pwr Offset

Avg

+/-

Ch 2

Freq

Pwr Offset

Ch 2

Freq

Pwr Offset

Shift

dBm

Ch 2

Enter

Freq

Pwr Offset

Operating Guide 1-25

Chapter 1 Getting Started

Operating the Counter

Using Power Correction

The Power Correction function in the main Menu allows you to set the Counter to automatically compensate for power loss (or gain) that occurs in the test configuration, such as attenuation resulting from cable impedance. You can choose from nine power-correction profiles that are stored in nonvolatile memory, and you can modify the contents of these profiles.

at the frequency being measured. When a measured frequency does not match any of the frequency values defined in the currentl y selected profile, the Counter interp ol ates for t he measur ed freq ue ncy to determi ne the appropriate value to add to the power measurement. The correction profiles require a minimum of two data points per profile.

Power Correction Theory of Operation

When the Counter interpolates between data points to determine the amount of correction to apply to the current measurement, it computes the correction based on a straight line plotted between the frequency values in the two closest data points. Therefore, a graph of a power-correction

profile would show a “curve” that consists of two to nine straight-line segments, rather than a true curve, as shown below.

P o w e

F r e q u e n c y

1-26 Operating Guide

Chapter 1 Getting Started

Operating the Counter

NOTE

As the graph shows, the Counter never computes power-corr ection values for loss above the zero axis. Conversely, corrections are never computed for gain below the zero axis. Once the correction value reaches the zero axis, no further corrections are applied.

When the Counter i nterpolat es fo r freq uencies t hat ar e abov e or b elow t he range of frequencies specified in the currently selected profile, it never computes a value that would fall on the opposite side of the zero axis from the closest specified frequency. In other words, if there are two or more data points that contain loss values, the Counter never computes or applies a correction that would be indicative of gain. Conversely, if there are two or more data points that contain gain values (negative loss values), the Counter never applies a correction that would be indicative of loss. Since there can be no further change in the loss or gain values once the zero axis is reached, no power corrections are applied when the input frequency reaches or passes a point in the profile that intersects the zero axis. Effectively, the Counter computes only loss-correction values or

gain-correction values—never both within the same profile. When you enter values in power-correction data points and then exit the

data-point display (using either the left-arrow key or the Enter key), the Counter immediately sorts all of the data-points into order by the frequency values. Therefore, if you enter a pair of values in a data point, exit the data-point displa y, and then immediatel y return to the disp lay for that data point, you may s ee different values than the ones you just entered. The values you entered may now be contained in a different ly numbered data point in the same profile, if they were previously entered out of order by frequency.

Increasing Profile Accuracy

To increase the accuracy of a power-correction profile, you can add data points between the existing data points in the profile (if less than 10 data points are in use), thus bringing the data points closer together and shortening the straight-line segments. If all ten data points are in use, you can add data points by using two or more profiles for a single test configuration. If you do this, you must se lect the profile you need (from the Menu) for the range of frequencies being measured. This means that you must select a different profile whenever the measured frequency moves outside the range of frequencies defin ed by the data points in the currently selected profile.

Operating Guide 1-27

Chapter 1 Getting Started

Operating the Counter

Selecting a Power-Correction Profile

The diagram on page 1-29 shows how to turn Power Correction on or off and how to select a power-correction profile.

NOTE

Pressing the Enter key when the number of a power-correction profile (1-9) is displayed selects that profile, enables Power Correction, and exits the Menu. If you intend to enter data in the currently displayed profile, press the right-arrow key instead of the Enter key to select the power-correction profile without exiting the Menu.

Entering Data Points in a Power-Correction Profile

The diagram on page 1-30 shows how to enter data points (frequency and loss values) in power-correction profiles. A minimum of two valid data points is required for Power Correction; you can enter up to ten data points in each power-correction profile. Each of the power-correction

profiles initially contains two valid data points—0.0 dB loss at 1 GHz, and

0.0 dB loss at the highest frequency the Counter can measure (20 GHz for the 53150A, 26.5 GHz for the 53151A, or 46 GHz for the 53152A). The remaining eight data points contain values of 0.0 dB loss at 0.0 GHz. When entering data, you can change the values in an existing data point or enter new values in a data point that currently has zero values.

1-28 Operating Guide

Chapter 1 Getting Started

Operating the Counter

Shift

Reset/ Local

Ch 2

Freq

Pwr

Ch 2

Freq

Pwr

dBm

Shift

NOTE

Ch 2

Enter

Freq

Pwr

dBm

Shift

When Power Correction is enabled, a lower-case letter “c” is displayed in the hundredths position of the po wer display.

Operating Guide 1-29

Chapter 1 Getting Started

Operating the Counter

+/-

1-30 Operating Guide

Chapter 1 Getting Started

Operating the Counter

NOTES

•

Pressing the Enter key after entering values exits the Menu and restores the measurement display. To remain in the Power Correction menu so you can enter or change values in another data point in the currently selected, press the left-arrow key repeatedly (after entering the

values for a data point) until “PWR CORR” is re-displayed, and then press the up- or down-arrow key to choose the next data point you want to edit.

•

When you are entering or editing values in data points, the 10 single-line annunciators that are part of the analog power display are used to indicate which data point is being displayed. The left-most annunciator indicates that the data displayed is contained in the lowest data point, data point 1. When the first two annunciators on the left are activated, this indicates data point 2, and so on through data point 10, which is indicated by all 10 annunciators.

•

The Power Correction function can be used to correct for gain from amplification as well as for loss from attenuation. Since Power Correction is intended primarily to correct for loss, loss values are entered as positive numbers. To enter values for gain, use the Sign key (+/–) to change the sign of the value you enter.

Operating Guide 1-31

Chapter 1 Getting Started

Operating the Counter

Setting the Measurement Rate

The measurement rate determines how frequently the Counter takes measurements. You can set the measurement rate to FAST, MED (medium), SLOW, or HOLD (single measurement taken each time you press the Reset/Local key).

Ch 2

Freq

Rate

Ch 2

Enter

Freq

Hold

1-32 Operating Guide

Chapter 1 Getting Started

Operating the Counter

Setting the Number of Averages

You can set the number of me asureme nts t he Coun ter ta kes and averag es before displaying the result. The default setting is one (no averages are performed), and the maximum setting is 99. Note that the tens position (10 through 90) and the units position (0 through 9) are adjusted separately, and that you cannot set the number of averages to zero.

NOTE

When a large number of averages is selected in combination with a high resolution setting (e.g., 1 Hz), it takes a considerable amount of time for the Counter to ta ke the mea surements, co mpute the a verages, and dis play a reading. As a result, the rate at which the display is updated is considerably slower than at small numbers of averages and lower resolution settings.

xxxxxx

Ch 1

Freq

Avg

Ch 1

Enter

Freq Avg On

Ch 1

Enter

Freq Avg On

Operating Guide 1-33

Chapter 1 Getting Started

Operating the Counter

NOTE

For most of the Counter’s settings, when you continue to press either the up-arrow or the down-arrow key when you reach the end of the available settings, the value for the setting “rolls ove r” to the value at the opposite end of the range. For example, if the HP-IB address is set to 31, and you press the up-arrow key, the va lue changes to one.

However, when you adjust the value in the units position for the number of measurements to be averaged, rollover does not occur. If you press the up-arrow when the value in the tens position is zero and the value in the units position is nine, or if you press the down-arrow when the value in the tens position is zero and t he val ue i n th e units pos iti on is o ne, ther e is no change. If the value in the units position could roll over (in either direction), it would allow you to set a value of zero for the number of averages. Since at least one measurement must be taken, zero is an illegal value.

Setting the Resolution

Since less time is required to compute each measurement as the resolution of the meas urements is reduced, the resolution setting affects the rate at which measurements are taken and displayed, as well as the number of digits displayed for the measurements. As a result, the rate at which the Gate indicator fl ashes chan ges when you change the resolu tion.

As shown in the procedure in the diagram on the next page, the available resolution settings are 1 Hz (the default setting), 10 Hz, 100 Hz, 1 KHz, 10 KHz, 100 KHz, and 1 MHz.

NOTE

When the resolution setting is high (e.g., 1 Hz), and a large number of averages is selected, it takes a considerable amount of time for the Counter to take the measurements, compute the averages, and display a reading. As a result, the rate at which the display is updated is considerably slower than at small numbers of averages and lower resolution settings. For example, when the resolution is set to 1 Hz, and the number of averages is set to 60, a new reading is displayed every 60 seconds (approximately).

1-34 Operating Guide

Chapter 1 Getting Started

Operating the Counter

Resol

Ch 2

Freq

Ch 2

Enter

Freq

Operating Guide 1-35

Chapter 1 Getting Started

Operating the Counter

1-36 Operating Guide

Operating Your Frequency Counter

Operator’s Reference

Chapter 2 Operating Your Frequency Counter

Introduction

This chapter contains information and usage procedures for the front-panel keys, operating functions, and menus of the HP 53150A/151A/152A Microwave Frequency Counter.

Chapter Summary

• How this Counter Works for You pg. 2-3

• Summary of the Measurement Sequence pg. 2-4

• Using the Selection Keys pg. 2-5

• Numeric Entry pg. 2-6

• Changing States pg. 2-7

• Acknowledging Messages pg. 2-9

• Using the Clear and Reset/Local Keys pg. 2-9

• Other Function Selection Keys pg. 2-10

• Measuring Frequency pg. 2-12

• Setting the Resolution and the Measurement Rate pg. 2-14

• Setting the Number of Averages pg. 2-17

• Measuring Relative Frequency pg. 2-20

• Offsetting a Frequency Measurement pg. 2-21

• Measuring Power pg. 2-24

• Measuring Relative Power pg. 2-26

• Offsetting a Power Measurement pg. 2-27

• Using Power Correction pg. 2-30

• Using the Menu pg. 2-39

2-2 Operating Guide

Chapter 2 Operating Your Frequency Counter

How this Counter Works for You

The following is a list of some of the key things the Counter does for you.

• Presets the menus to default states and values at power-up

• The Counter’s Menu key and other front-panel keys allow you to select

such things as the timebase source, the HP-IB address, and the RS-232

serial-port baud rate. The Counter also allows you to store your

selections in non-volatile memory; thus, these settings are not lost

when power has been off or after a remote-interface reset.

• Automatically displays measurement(s) when you have selected a

measurement function.

• Accepts your entry for a menu item when you press the Enter key. You

must press the Enter key to complete each setting and/or selection.

• Saves user configuration settings.

Operating Guide 2-3

Chapter 2 Operating Your Frequency Counter

Summary of the Measurement Sequence

1. Turn on the Main ~ Power switch on the back panel, and then press and release the POWER button on the front panel.

NOTE

The internal Reference Oscillator receives power only when the Main ~ Power switch is on. Therefore, the f requency of the refe rence si gnal may drift until the oscillator stabilizes. Specifications for the stability of the standard internal timebase and the optional Oven Timebase are provided in Chapter 3.

2. Connect the input signal to the appropriate input connector (Channel 1 or Channel 2).

3. Connect an external reference signal to the External Reference connector on the back panel (if de sired).

4. Press the Chan Select key to select the input channel (if necessary).

5. Press the Display Power key if you need to measure power (Channel 2 only).

6. Press the frequency and/or power Offset On/Off keys to enable offset measurements (if desired), and then use the Freq Offset (Shift + Rate) and/or Pwr Offset (Shift + Avg) keys to enter the offset values.

7. Use the Resol, Rate, and Avg keys to configure the display.

8. Use the Menu (Shift + Re set/Local) key to set the reference-oscillator source, to select the Channel 1 low-pass filter, to configure the

Counter’s response to frequency modulation, to enable and configure Power Correction, and/or to select a previously saved set of user settings.

9. If you intend to operate the counter remotely using the HP-IB, use the HP-IB (Shift + Resol) key to configure the HP-IB.

10.If you intend to operate the counter remotely using the serial interface, use the Menu (Shift + Reset/Local) key to adjust the serial port Baud rate.

2-4 Operating Guide

Chapter 2 Operating Your Frequency Counter

Enter

+/-

Using the Selection Keys

There are six Selection keys—four “arrow” keys, the Enter key, and the sign (+/–) key. The functions of the arrow keys depend on the Counter’s operating mode (i.e., sequencing through choices in the Menu, numeric entry, state change, etc.). This section describes how the Selection keys function in these different operating modes.

Sequencing Through the Menu

To access the Menu, press the Shift key, and then press the Menu (Reset/Local) key.

NOTE

Reset/ Local

Shift

• Press the up- or down-arrow key to go forward to the next menu function or back to the previous menu function. Pressing either of these keys repeatedly cycles through the list of menu functions.

• Press the right-arrow key to select a function. When you do this, the flashing annunciator ( ) changes direction and the current setting flashes to indicate that you can now use the up- and down-arrow keys to cycle through the available settings.

• Press the up- or down-arrow key to move through the list of available settings for a function. Pressing either of these keys repeatedly cycles through the list of settings.

• Press the Sign (+/–) key to change the sign of numeric values.

• Press the Enter key to accept the currently displayed setting and exit

the Menu.

In most cases, when you reach the to p or bottom o f a list of se tti ngs, or the left or right end of a numerical field, the focus rolls over to the opposite end of the list of settings, or wraps around to the opposite end of the numeric field. In some situations, however, this does not occur, because if it did, you could choose an illegal setting. For these settings, you have to use the opposite button to cycle back through the values or settings.

Operating Guide 2-5

Chapter 2 Operating Your Frequency Counter

Enter

+/-

Using the Selection Keys

Numeric Entry

Several menu functions, and several functions that have dedicated keys on the front panel, require you to enter numeric values.

• Press the (left-arrow) and (right-arrow) keys to move left and right to select adjustable digits (the selected digit flashes).

• Press the (up-arrow) and/or (down-arrow) key to increment and decrement the selected (fl ashing) digit of the displayed value (see note on previous page).

• Press the Sign (+/–) key to change the sign of the numeric value.

• Press the Enter key to complete a numeric entry. (If you change the

value of a numeric entry, but you forget to press the Enter key, the value of the entry is not changed.)

2-6 Operating Guide

Chapter 2 Operating Your Frequency Counter

Using the Selection Keys

Changing States

Several menu functions, and several functions that have dedicated keys on the front panel, require you to choose from a list of available states. These functions and the states you can choose for each of them are:

• Reference Oscillator (REF OSC)

– Internal (INT) – External (EXT)

• Serial Port Baud Rate (BAUD)

– 1200 – 2400 – 4800 – 9600 – 14400 – 19200

• Frequency Modulation (FM)

– Automatic (AUTO) –Off (OFF)

• Channel 1 Low-Pass Filter (CH1 LPF)

–On (ON) –Off (OFF)

• Measurement Rate (Rate key)

–Fast (FAST) – Medium (MED) –Slow (SLOW) –Hold (HOLD)

• Resolution (Resol key)

– 1 Hz, 10 Hz, 100 Hz, 1 KHz, 10 KHz, 100 KHz, 1 MHz

Operating Guide 2-7

Chapter 2 Operating Your Frequency Counter

Using the Selection Keys

Use the Selection keys as described below to change the state of these functions:

• When the annunciator ( ) in the display f lashes, pres s the right -arrow key to move the focus from the displayed menu function (or frontpanel-key function) to the setting for that function.

• Press the up- or down-arrow key to cycle through the available choices.

Press the Enter key to complete the setting. (If you change the setting of a function, but you forget to press the Enter key, the setting of the function is not changed.)

NOTE

The Sign key has no function and is ignored in menu selections and front-panel functions that have state-change selections only.

2-8 Operating Guide

Chapter 2 Operating Your Frequency Counter

Reset/ Local

Freq Offset

On/Off

Clear

Rate

Shift

Using the Clear and Reset/Local Keys

The Clear key and the Reset/Local key have similar functions in the Menu and in other front-panel- key function s ettings, but their e ffects v ary

with the Counter’s state and condition. In general, the Reset/Local key restores the setting that was in effect when you entered the Menu or front-panel-key function, but it does not close the Menu or the function-setting display. The Clear key also restores the previous setting, but it closes the Menu or the front-panel-key function-setting display at the same time.

If you press the Reset/Local key while the Counter is taking measurements, it resets the current operation and forces the Counter to reacquire and re-measure the signal.

Pressing the Reset/Local key while the Counter is in Remote Mode forces the Counter into Local Mode and enables all of the front-panel controls.

Acknowledging Messages

When a message is di splayed , pr ess th e Reset/Local key, the Clear key, or the Enter key (after reading the message) to acknowledge it and erase it from the display.

Operating Guide 2-9

Chapter 2 Operating Your Frequency Counter

MODIFY

HPIB

Pwr Offset

Freq Offset

On/Off

ResolAvg

+/-Clear

Rate

Enter

Pwr Offset

Freq Offset

On/Off

Avg

+/-Clear

Rate

POWER

FREQ

Gate

Rel Freq Rel Pwr

dBm/ W

Channel 2

Chan Select

Offset On/Off

Display Power

Other Function Selection Keys

There are several functions that you access directly from front-panel keys (not from within the Menu). These functions are:

• Measurement Rate (Rate key)

• Number of Averages (Avg key)

• Display Resolution (Resol key)

• HP-IB Address (HPIB key)

Use the Selection keys in the manner described earlier in this chapter (see

“Numeric Entry” and “Changing States”) to adjust the settings for these functions. Detailed procedures for using the Rate, Avg, Resol, and HPIB keys are provided later in this chapter.

There are also a number of functions that are toggled between states (no selections are displayed) using named front-panel keys. These are:

• Display backlight on and off ( On/Off). Press Shift, and then press the On/Off / Clear key.

• Channel selection (Chan Select). Press Chan Select to switch between the two input channels.

• Display power measurement (Display Power). Press Display Power to turn the power-measurement function on and off.

• Frequency offset measurement (FREQ Offset On/Off). Pres s th e Off set On/Off key in the FREQ area of the front panel to turn the frequency

offset function on or off.

• Power offset measurement (POWER Offset On/Off). Press the Offset On/Off key in the POWER area of the front pa nel to turn the power

offset function on or off (the Display Power function must be on).

• Relative frequency measurement (Rel Freq). Press Shift, and then press the Rel Freq (Offset On/Off) key to measure the difference in frequency between the current measurement and the measurement taken at the time you pressed the Rel Freq key (drift).

2-10 Operating Guide

Chapter 2 Operating Your Frequency Counter

Other Function Selection Keys

• Relative power measurement (Rel Pwr). Press Shift, and then press the Rel Pwr (Offset On/Off) key to measure the difference in power

between the current measurement and the measurement taken at the time you pressed the Rel Pwr key.

Operating Guide 2-11

Chapter 2 Operating Your Frequency Counter

Main ~ Power

CHANNEL 2

50 MHz to 20 GHz

DAMAGE

+27 dBm

50 W

Measuring Frequency

1 Connect the Counter to a power source, and set the

Main ~ Power switch on the back panel to 1 (on).

If the Counter is connected to an AC power source, the Main AC Power indicator on the back panel and the Standby indicator on the front panel light. If the Counter is connected to an external DC power source or is operated from internal batteries (with Battery option only), the Standby indicator lights, but the Main AC Power indicator does not.

2Press the POWER button on the front panel.

The Standby indicator goe s off, and all segments of t he front-panel display

POWER

Standby

are temporarily activated. TESTING is displayed while the Counter performs its power-on self- test. If the Coun ter passes all of the tests, SELF TEST OK is displayed, and the Counter then displays its model number, firmware version number, HP-IB address, and CH2 NO SIGNAL. The Counter is now ready to measure the frequency of a signal applied to the Channel 2 input. Note that the Ch 2 and Freq annunciators are activated.

3 Connect an input signal to Channel 2.

CAUTION The Channel 2 input path circuits contain sensitive GaAs semiconductors.

To prevent damage to these components, always adhere to standard ESD (ElectroStatic Discharge) prevention procedures, and ensure that the maximum power specification for this channel (+27 dBm) is not exceeded.

The Counter automatically displays the measured frequency of the input signal. To set the resolution, measurement rate, and/or the number of

averages, see the appropriate procedure in the section titled “Operating the Counter,” or refer to “Setting the Resolution,” “Setting the Measurement Rate,” and “Setting the Number of Averages,” later in this chapter.

2-12 Operating Guide

Chapter 2 Operating Your Frequency Counter

Measuring Frequency

NOTE

FREQ

Chan Select

Gate

When the frequency of a si gnal a pplied t o the Channel 2 in put exce eds th e maximum rated frequency for the instrument, the Counter displays CH2 TOO HIGH.

4 To measure the frequency of a signal applied to the Channel 1

input, press the Chan Select key.

CHANNEL 1 is displayed momentarily, and the Ch 1 and Freq annunciators are activated. If a signal is presently applied to the Channel 1 input, the measured frequency is then displaye d. If no sign al is applied, CH1 NO SIGNAL is displayed until an input signal is connected to the Channel 1 input connector.

Operating Guide 2-13

Chapter 2 Operating Your Frequency Counter

Setting the Resolution and the Measurement Rate

The number of measurements the Counter makes in a given amount of time is affected by the Rate setting, the Resolution setting, and the quality of the input signal (signal quality affects the amount of time the Counter requires to determine an accurate measurement). By adjusting the Resolution and Rate settings, you can affect how often the Counter takes measurements.

Setting the Resolution

The Counter’s resolution setting determines the number of digits displayed for measurement s and the preci sion of the measurement s. Since less time is required to compute each measurement as the resolution of the measurements is reduced, the resolution setting also affects the rate at which me asurements are taken and displayed. As a result, the flash rate of the Gate indicator changes when you change the resolution.

The numerals shown for the value of the measurement are displayed in four groups of three digits, as shown below (the leading zero is suppressed):

GHz MHz kHz Hz

Ch 2

Freq

2-14 Operating Guide

Chapter 2 Operating Your Frequency Counter

Enter

HPIB

Resol

Setting the Resolution and the Measurement Rate

Resolution Setting Exampl e

For the following example, use the 10 MHz output from the reference timebase as the input to Channel 1.

1 Press the Resol key to enter the resolution-setting mode.

The current resolution setting is displayed (the current value and the indicator between the arrow keys are flashing to indicate that you can use the up- and down-arrow keys to change the setting).

2 Press the up-arrow or down-arrow key to decrease or increase the

resolution.

You can press these keys as many times as necessary to locate the setting you want to use. The available resolution settings are 1 Hz (the default setting), 10 Hz, 100 Hz, 1 KHz, 10 KHz, 100 KHz, and 1 MHz.

3Press the Enter key to activate your setting and exit the

resolution-setting mode.

The setting you chose is now in effect. The number of digits displayed for the measurement is adjusted accordingly; you can observe the affect on measurement speed by monitoring the flash rate of the Gate indicator.

NOTE

The measurement resolution has a direct effe ct on th e amo unt of time the Counter requires to complete a measurement. Measurements made at the

Counter’s maximum resolution setting (1 Hz) are noticeably slower than at lower resolutions. This is especially noticeable when the Counter is set to average a number of measurements.

Operating Guide 2-15

Chapter 2 Operating Your Frequency Counter

Freq Offset

Clear

Rate

On/Off

Hold

Setting the Resolution and the Measurement Rate

Setting the Measurement Rate

The measurement Rate setting determines how frequently the counter initiates measurements. Since the actual measurement rate is also affected by the resolution setting and the signal quality, as mentioned earlier, the available rate settings (FAST, MED, and SLOW) do not equate to a fixed number of measurements in a given amount of time.The HOLD setting turns off automatic measurements, so that a single measurement is made each time you press the Reset/Local key.

Rate Setting Example

1 Press the Rate key to enter the rate-setting mode.

The current rate setting is displayed (the current value and the indicator between the arrow keys are flashing to indicate that you can use the upand down-arrow keys to change the setting).

2 Press the up-arrow or down-arrow key to decrease or increase the

measurement rate.

You can press these keys as many times as necessary to locate the setting you want to use. The available resolution settings are FAST, MED, SLOW, and HOLD.

3Press the Enter key to activate your setting and exit the rate-

setting mode.

The setting you chose is now in effect. The measurement rate is adjusted accordingly; you can observe the effect on measurement speed by monitoring the flash rate of the Gate indicator. There is no annunciator on the display for the rate setting, unless you set the rate to HOLD.

4 If you set the rate to HOLD, press the Reset/Local key to initiate a

measurement.

The Counter displays the MEASURING message while it computes the measurement, and then displays the result. Press the Reset/Local key again each time you want to take an additional measurement.

2-16 Operating Guide

Chapter 2 Operating Your Frequency Counter

Pwr Offset

+/–

Avg

Setting the Number of Averages

You can set the counter to take a variable number of measurements and average them mathematically before displaying the result (the Counter computes a running average). This feature can be used to determine the effective frequency of a signal that is fluctuating and to retain some of the precision of a maximum-resolution measurement of a fluctuating signal.

The default number of averages is one, which means that no averages are performed, and the maximum setting is 99. Note that the tens p osition (10 through 90) and the units position (0 through 9) are adjusted separatel y, and that it is not possible to set the number of averages to zero.

NOTE

Averages Setting Example

1 Press the Avg key to enter the averages-setting mode.

The current averages setting is displayed (the current value and the indicator between the arrow keys are flashing to indicate that you can use the up- and down-arrow keys to change the setting).

2 Press the up-arrow or down-arrow key to decrease or increase the

value for the units position of the number of averages.

Operating Guide 2-17

Chapter 2 Operating Your Frequency Counter

Ch 12

Rel Freq

Avg On

Setting the Number of Averages

NOTE

3 Press the left-arrow key once to move the focu s to the tens

position, and then use the up- and/or down-arrow key to set the value for the tens position (if desired).

Note that the tens and units values are set separately.

4Press the Enter key to activate your setting and exit the averages-

setting mode.

The Avg On annunciator is activated, and the Counter displays AVERAGING while it takes the first set of measurements. The length of

time that th e AVERAGING message is displayed varies primarily with setting for the number of averages, but it is also affected by other factors, such as the current resolution and rate settings and the quality of the signal. Once the first set of averages is complete and the result is displayed, the Counter continues to display that result until the next set of averages is complete.

If the measurement rate is set t o HOLD, and a value larger than one is set for averages, the first set of measurements is not initiated until you press the Reset/Local key. When you do, the Counter displays the AVERAGING message while it takes the first set of measurements. When the first set of measurements is complete, and the averaging result is displayed, the

2-18 Operating Guide

Chapter 2 Operating Your Frequency Counter

Setting the Number of Averages

Counter remains in this state until you press the Reset/Local key to initiate another set of measurements, change the value for averages back to one, or change the setting for the measurement rate to SLOW, MED, or

HIGH.

Operating Guide 2-19

Chapter 2 Operating Your Frequency Counter

Ch 2

Rel Freq

Measuring Relative Frequency

You can measure the difference in frequency from one measurement to another (frequency drift) or between two separate input signals using the Relative Frequency function.

Relative Frequency Example

Press the Shift key, and then press the Rel Freq (FREQ Offset On/Off) key. The Shift annunciator activates when you press the Shift key. When you press the Rel Freq (FREQ Offset On/Off) key, the Shift annunciator disappears, and the Rel Freq annunciator in the upper-left corner of the display activates. At the same time, the Counter saves the frequency measurement it was displaying at the time you pressed the Rel Freq key, and it computes and displays the difference between that measurement and the current measurement.

You can also use the Relative Frequency function to measure the

difference between two different signals. To do this, acti vate the Relative Frequency function, as described in the previous paragraph, disconnect the cable supplying the signal to the input connector, and then connect the second signal to the same input connector. The value displayed when the Counter acquires the second signal is the frequency difference between the two signals.

2-20 Operating Guide

Chapter 2 Operating Your Frequency Counter

Offsetting a Frequency Measurement

To display an offset frequen cy measurement, you need to set the valu e and sign (+/–) of the offset and to turn the Frequency Offset function on. In the following example, the Frequency Offset function is enabled first, and the

offset value is then entered . Howeve r, the order doesn’t matter, so you ca n also enter the offset value first, and then turn the offset function on.

Frequency Offset Example

1 Connect a cable from the 10 MHz reference output on the back

panel to the Channel 1 input connector, and press the Chan Select key (if necessary) to activate Channel 1.

The display should look like this:

GHz MHz kHz Hz

Ch 1

Rel Freq

2Press the Shift key, and then press the Freq Offset (Rate) key.

The Shift annunciator activates when you press the Shift key. When you press the Freq Offset key, the Shift annunciator disappears, and the Freq

Offset annunciator at the left side of the display activates.

Operating Guide 2-21

Chapter 2 Operating Your Frequency Counter

Offsetting a Frequency Measurement

3 Use the left- and right-arrow keys to move the focus to the digit(s)

in the frequency-offset display that you need to adj ust to enter the offset value, and then use the up- and down-arrow keys to adjust the value for each digit. Enter a value of 500 Hz.

The flashing digit is the digit that currently has the focus. This means that you can change the value of the flashing digit using the up- and down-arrow keys.

4 Press the sign (+/–) key (if desired) to change the si gn of th e offse t

value.

The display should look like this:

GHz MHz kHz Hz

Ch 1 Rel Freq Offset

5Press the Enter key to confirm the offset value and exit the

offset-entry display.

The Freq Offset annunciator is deactivated, and the measurement display returns.

NOTE

2-22 Operating Guide

Chapter 2 Operating Your Frequency Counter

Offsetting a Frequency Measurement

6Press the Offset On/Off key.

The Freq Offset annunciator is activated, and the value of the display is adjusted to reflect the value and sign of the offset entered in Steps 2 and 3.

The display should look like this:

GHz MHz kHz Hz

Ch 1

Rel Freq

Offset

Since the offset function can be used to add or subtract a fixed value to/from the measurement result, you can use this feature to tune or align the odd frequencies of a local oscillator (LO). If you enter the target frequency as a negative offset, the Counter displays the difference

between the LO’s frequency and the target frequency. You can then adjust the LO until the Counter displays a value of zero.

NOTE

The maximum value that can be entered for Frequency Offset is ± 49,999,999,999 Hz.

Operating Guide 2-23

Chapter 2 Operating Your Frequency Counter

Measuring Power

The HP 53150A/53151A/53152A Microwave Frequency Counter can also measure signal power (in the same frequency ranges as for frequency measurements) on Channel 2. The p ower measurement, w hich is shown in a dedicated area of the display, includes a digital readout and an analog representation that is useful when peaking signals. The display can be configured to show power in units of dB, dBm, W, mW, µW, and percentage (%).

CAUTION The Channel 2 input path circuits contain sensitive GaAs semiconductors.

Power Measurement Example

input connector.

1Press the Display Power key to enable power measurement.

The Pwr annunciator at the left side of the display is activated, and the

Counter’s digital and anal og power di splays sho w the powe r measurement in dB or dBm (the default units of measurement).

The display should look like this:

This example assumes that a signal is currently applied to the Channel 2

Ch 12

Rel Freq

dBm

Rel Pwr

Watts mW uW %

2-24 Operating Guide

Chapter 2 Operating Your Frequency Counter

Measuring Power

2Press the Shift key, and then press the dBm/W (Display Power) key.

When you press the Shift key, the Shift annunciator is activated. When you press the dBm/W (Display Power) key, the Shift annunciator goes off, and the units of measurement annunciator group to the right of the digital power measurement changes from dB or dBm t o W, mW, or µW, as shown below:

Ch 12

Rel Freq

dB dBm

Rel Pwr

Watts

uW %

NOTE

When the power of a signal applied to the Channel 2 input exceeds the maximum rated power for the instrument, the Counter displays HI.

Operating Guide 2-25

Chapter 2 Operating Your Frequency Counter

Ch 12

Rel Freq

Rel Pwr

Measuring Relative Power

You can measure the difference in power from one measurement to another or between two separate input signals using the Relative Power function.

Relative Power Example

Press the Shift key, and then press the Rel Pwr (PWR Offset On/Off) key. The Shift annunciator activates when you press the Shift key. When you press the Rel Pwr key, the Shift annunciator disappears, and the Rel Pwr annunciator at the left side of the display activates. At the same time, the Counter saves the power measurement it was di sp laying at the time you pressed the Rel Pwr key, and it computes and displays the difference in power between that measurement and the current measurement.

NOTE

When the Counter is set to measure power in dBm, relative power is expressed in dB. When the Counter is set to measure power in Watt s, mW, or, µW, power relative power is expressed as a percentage (%).

You can also use the Relative Power function to measure the difference in power between two different signals. To do this, activate the Relative Power function, as described in the previous paragraph, disconnect the cable supplying the signal to the input connector, and then connect the second signal to the same input connector. The value displayed when the Counter acquires the second signal is the power difference between the two signals.

2-26 Operating Guide

Chapter 2 Operating Your Frequency Counter

Offsetting a Power Measurement

You can use the Power Offset (Pwr Offset) function to add or subtract a constant value to/from a power measurement. For example, you can use an offset to compensate for a systematic error, to display the difference in power between two signals, or to compensate for losses and attenuation in cables or components that are between the signal source and the Counter.

To display an offset power measurement, you set the value and sign (+/–) of the offset and turn the Power Offset function on. In the following example, the Power Offset function is enabled first, and the offset value is then entered. However, the order doesn’t matter, so you can also enter the offset value first, a nd then turn the offset function on.

Power Offset Example

1 Connect a signal to the Channel 2 input connector, and activate

power measurement by pressing the Display Power key.

The display should look like this (except for the values, which are simulated in the illustration):

Ch 12

Rel Freq

dBm

Rel Pwr

Watts mW uW %

Operating Guide 2-27

Chapter 2 Operating Your Frequency Counter

Offsetting a Power Measurement

2 Press the Shift key, and then press the Pwr Offset (Avg) key.

The Shift annunciator activates when you press the Shift key. When you press the Pwr Offset key, the Shift annunciator and the f requency display disappear, the Pwr Offset annunciator at the left side of the display activates, and the power offset value is set to 00.00, as shown below:

Ch 12

Rel Freq

dBm

Rel Pwr

Offset

Watts mW uW %

3 Use the left- and right-arrow keys to move the focus to the digit(s)

in the power-offset display that you need to adjust to enter the offset value, and then use the up- and down-arrow keys to adjust the value for each digit.

The flashing digit is the digit that currently has the focus. This means

that you can change the value of the flashing digit using the up- and down-arrow keys.

NOTE

If you enter a value for Power Offset that results in a power reading that

is out of the Counter’s specified power-measurement range, the Counter displays HI in the power displa y when the Power Offset function is enabled.

4 Press the Sign (+/–) key (if desired) to change the si gn of the offset

value.

Ch 12

Rel Freq

dBm

Rel Pwr

Offset

Watts mW uW %

2-28 Operating Guide

Chapter 2 Operating Your Frequency Counter

Offsetting a Power Measurement

5Press the Enter key to confirm the offset value and exit the offset-

entry display.

The Pwr Offset annunciator is deactivated, and the measurement display returns.

6Press the Offset On/Off key (in the POWER area of the front panel).

The Pwr Offset annunciator is activated, and the value of the display is adjusted to reflect the value and sign of the offset entered in Steps 3 and 4.

The display should now look like this (values are simulated):

Ch 12

Rel Freq

dBm

Rel Pwr

Offset

Watts mW uW %

NOTE

When you are entering a value f or Power Of fset (or Freque ncy Offset ), you can use the Reset key to restore all of the displayed digits to zero. These are the only two functions in which the Reset key has this effect.

Operating Guide 2-29

Chapter 2 Operating Your Frequency Counter

Using Power Correction

The Power Correction function in the main Menu allows you to set the Counter to automatically compensate for power loss (or gain) that occurs in the test configuration, such as attenuation resulting from cable impedance. You can choose from nine power-correction prof iles that are stored in nonvolatile memory, and you can modify the contents of these profiles.

Each profile is defined by two t o ten da ta po int s (a da ta po int con si sts of a loss value and a frequency value). When Power Correction is enabled, the Counter automatically adds a correction to the power reading (determined from the data points in the profile) that compensates for the loss (or gain) at the frequency being measured. When a measured frequency does not match any of the frequency values defined in the currentl y selected profile, the Counter interp ol ates for t he measur ed freq ue ncy to determi ne the appropriate loss value to add to the power measurement.

A minimum of two valid data points is required for Power Correction; you can enter up to ten data points in each power-correction profile. Each of

the power-correction profiles initially contains two valid data points—

0.0 dB loss at 1 GHz, and 0.0 dB loss at the highest frequency the Counter can measure (20 GHz for the 53150A, 26.5 GHz for the 53151A, or 46 GHz for the 53152A). The remaining eight data points contain values of 0.0 dB loss at 0.0 GHz. When entering data, you can change the values in an existing data point or enter new values in a data point that currently has zero values. The data points are automatically sorted into order by frequency as you finish entering each one.

2-30 Operating Guide

Chapter 2 Operating Your Frequency Counter

Using Power Correction

Power Correction Theory of Operation

profile would show a “curve” that consists of two to nine straight-line segments, rather than a true curve, as shown below.

P o

NOTE

F r e q u e n c

When the frequency value of a signal is beyond either end of the curve specified by the values in the currently selected profile’s data points, the Counter computes a correction by extending the straight line defined in the last two data point s in the pro file .

As the graph above shows, the Counter never computes power-correction values for loss above the zero axis. Conversely, corrections are never computed for gain below the zero axis. When the Counter interpolates for frequencies that are above or below the range of frequencies specified in the currently selected profile, it never computes a value that would fall on the opposite side of the zero axis from the closest specified frequency. In other words, if there are two or more data points that contain loss values, the Counter never computes or applies a correction that would be indicative of gain. Conversely, if there are two or more data points that contain gain values (negative loss values), the Counter never applies a correction that would be indicative of loss. Since there can be no further

Operating Guide 2-31

Chapter 2 Operating Your Frequency Counter

Using Power Correction

change in the loss or gain values once the zero axis is reached, no power corrections are applied when the input frequency reaches or passes a point in the profile that intersects the zero axis. Effectively, the Counter

computes only loss-correction values or gain-correction values—never both within the same profile.

When you enter values in power-correction data points and then exit the data-point display (using either the left-arrow key or the Enter key), the Counter immediately sorts all of the data-points into order by the frequency values. Therefore, if you enter a pair of values in a data point, exit the data-point displ ay, and then immediatel y return to the disp lay for that data point, you may s ee different values than the ones you just entered. The values you entered may now be contained in a different ly numbered data point in the same profile, if they were previously entered out of order by frequency.

Increasing Profile Accuracy

To increase the accuracy of a power-correction profile, you can add data points between the existing data points in the profile (if less than 10 data

points are in use), thus bringing the data points closer together and shortening the straight-line segments. If all ten data points are in use, you can add data points by using two or more profiles for a single test configuration. If you do this, you must se lect the profile you need (from the Menu) for the range of frequencies being measured. This means that you must select a different profile whenever the measured frequency moves outside the range of frequencies defin ed by the data points in the currently selected profile.

Power Correction Examples

The procedures for using Power Correction and entering loss (or gain) and frequency values in power-correction profiles are demonstrated in the Power Correction examples on the following pages. The first example, on page 2-33, shows how to select a power-correction profile and enable Power Correction and also shows how to disable Power Correction.The second example, on page page 2-35, shows how to enter data in the power-correction profiles.

2-32 Operating Guide

Chapter 2 Operating Your Frequency Counter

Using Power Correction

Power Correction Example: Selecting a Correction Profile

1Press the Shift key, and then press the Menu (Reset/Local) key.

2 Press either the up- or down-arrow key repeatedly until “PWR

CORR > OFF” is displayed as shown below:

3 Press the right-arrow key once.

The flashing pointer in the Power Correction display changes direction to indicate that you can now use the up- and down-arrow keys to select a power-correction profile (or select OFF to disable Power Correction). The current setting for Power Correction (OFF or a number between 1 and 9) also flashes.

4 Press the up- and/or down-arrow key repeated ly until the number

of the power-correction profile you want to use is displayed. For this example, choose profile number 3.

If no data points were entered into the correction profiles p reviou sly, each of the nine power-correction profiles contains only two valid data

points—0.0 dB loss at 1 GHz and 0.0 dB loss at the highest frequency the Counter can measure (20 GHz for the 53150A, 26.5 GHz for the 53151A, or 46 GHz for the 53152A). The remaining eight data points in each of the profiles initially contain values of 0.0 dB loss at 0.0 GHz. (This example assumes that valid loss and frequency values were previously entered in two or more of the data points in this profile.)

Operating Guide 2-33

Chapter 2 Operating Your Frequency Counter

Using Power Correction

5Press the Enter key to select profile number 3.

Power Correction is enabled using profile number 3, and the measuremen t display returns. The power reading now includes an adjustment for the loss incurred at the measured frequency. The amount of t he adjustment is derived from the loss and frequency values in the data points in the

selected profile. A lower-case letter “c” is shown in the hundredths position of the power-measurement display to indicate that Power Correction is enabled.

Ch 2

Freq

Pwr

dBm

NOTE

press the right-arrow key instead of the Enter key to select the power-correction profile without exiting the Menu.

You can also select a power-correction profile by pressing the right- or left-arrow key (instead of the Enter key). When you press either arrow key, you do not exit the Menu. As the next example shows, you should select a profile with the right-arrow key when you intend to enter or change the loss an d/or f requency va lues in the s elected profil e. You shoul d select the power-correction profile with the left-arrow key if you are done working with the power-correction settings, but you want to change settings for other functions in the Menu.

2-34 Operating Guide

Chapter 2 Operating Your Frequency Counter

Using Power Correction

Power Correction Example: Editing Data Point Values

1 Select a power-correction profile using the up- and/or

down-arrow keys (as shown in steps 1 through 4 in the previous example). For this example, choose profile number 3.

2 Press the right-arrow key.

The display changes to show the loss and frequency values stored in the data point that contains the lowest frequency value in the current profile.

The left and right pointers that are before and after the word “LOSS” are flashing.

The ten small, single-line annunciators that are below the analog power display are used to indicate which of the ten data points is currently displayed. In the example shown above, only the first annunciator is activated, which indicates that the values displayed are for data point 1, the lowest data point.

Operating Guide 2-35

Chapter 2 Operating Your Frequency Counter

Using Power Correction

3 To insert values in an empty data point, press the up- and/or

down-arrow key repeatedly to cycle through the data points in the selected profile to locate one that contains values of 0.0 for both loss and frequency.

For a profile that has not been previously used, the first two dat a points displayed contain values of 00.0 dB loss at 1.0 GHz and 00.0 dB loss at the highest frequency the Counter can measure (20 GHz for the 53150A,

26.5 GHz for the 53151A, or 46 GHz for the 53152A). The remaining data points contain values of 00.0 dB loss at 00.0 GHz. In profiles that have been previously used, all data points containing non-zero values are displayed in order from lowest to highest, and any zero-value data points are displayed above the non-zero data points. All data points are automatically sorted into order by frequency and saved whenever you select a different profile or exit the Power Correction menu.

4 To change a value (or values) in a data point, press the up- and/or

down-arrow key repeatedly until the data point that contains the value(s) you want to change is displayed, and then press the right-arrow key (the number of the data point displayed is

indicated by the number of annunciators to the right of the loss value).

The pointer to the left of the word “LOSS” stops flashing, the pointer to the right of the word “LOSS” changes direction and flashes, and the first digit of the frequency value flashes. This indicates that you can now adjust the value of the first digit in the frequency setting.

5 To adjust the value of the tens position of the frequency setting,

press the up- or down-arrow key until the desired value is displayed.

2-36 Operating Guide

Chapter 2 Operating Your Frequency Counter

Using Power Correction

6 Use the right-arrow key to move to each of the remaini ng digit s in

the frequency setting, and use up- and down-arrow keys to adjust their values, if necessary.

The currently selected digit flashes to indicate that it is the one that changes when you press the up- and down-arrow keys. You can also use the left-arrow key to back up to a previous digit, if necessary. However, be aware that the digit to the left of the one you are adjusting increments automatically to the next higher or lower value when the value of the currently selected digit exceeds nine or is incremented below zero.

7 To adjust the loss value, press the right-arrow key while the digit

in the tenths position of the frequency value and the pointer to

the right of “GZ” are flashing.

The pointer at the right end of the display changes direction, and the first digit (tens position) of the loss value flashes. You can now adjust its value using the up- and down-arrow keys.

8 Use the left- and right-arrow keys to navigate to the remaining

digits in the loss setting, and adjust their values (if necessary) with the up- and down-arrow keys.

9 Press the Sign (+/–) key to change the sign of the loss value (if

necessary).

Operating Guide 2-37

Chapter 2 Operating Your Frequency Counter

Using Power Correction

10 To add or adjust the values in another data point, press the

left-arrow key repeatedly until “PWR CORR” is re-displayed, and repeat steps 2 through 10. To edit data points within another power-correction profile, press the left-arrow key repeatedly until “PWR CORR” is re-displayed, and repeat steps 1 through 10.

NOTE

When a data point is entered in a profile, all of the data points in that profile are sorted by frequency and stored in that order. Therefore, the data points in a profile are always in order from the lowest frequency to the highest when you access a correction profile. The first data point displayed is always the data point that contains the lowest frequency value.

11 If you are done entering data-point values, press the Enter key to

accept your changes, save the data-point values, and return to the measurement display.

Power Correction is now enabled using the profile number 3.

NOTE

Ch 2

Freq

Pwr

dBm

You can include your selection of a power-correction profile in any of the nine sets of user settings s tored in non-v olatile memory (s ee page 2-46) by enabling the profile and then saving the set. If you save set 0 (zero) while Power-Correction is enabled, the currently-selected profile will be in effect whenever you turn on the Counter.

The data in the saved user settings and in all of the power-correction profiles is stored in non-volatile memory. If the Counter ever requires repair, and the main circuit-board assembly is replaced, these stored values will be lost. Therefore, to protect these values and ensure they are available for future use, you should keep an external record of them.

2-38 Operating Guide

Chapter 2 Operating Your Frequency Counter

Using the Menu

The HP 53150A/151A/152A Counter’s Menu makes it easy to control a number of the Counter’s features and functions. You use the Selection (arrow) keys to navigate to the setting you want to change and then to actually make the changes.

1 Press the Shift key and then the Menu (Reset/Local) key to displa y th e

Menu. When you press the Shift key, the Shift annunciator (near the bottom-right

corner of the display) activates. When you press the Menu (Reset/Local) key, the Shift annunciator goes off, and the first menu item is displaye d. If you have not previously invoked the Menu since you last turned the Counter on, the first menu item is REF OSC, the Reference Oscillator.

NOTE

2 Press the right-arrow key to change the setting for the Reference

Oscillator.

The flashing annunciator ( ) in the display reverses direction to indicate that you can now change the setting by pressing either the up-arrow key or the down-arrow key. In the case of the Reference Oscillator function, which has only two possible settings (INTernal and EXTernal), pressing either the up- arrow or the down-arrow has the same effect (it toggles the setting from INT to EXT or from EXT to INT).

The Counter will not switch to EXTernal unless a suitable reference signal is available at the External Reference connector.

Operating Guide 2-39

Chapter 2 Operating Your Frequency Counter

Using the Menu

3Press the Enter key to activate the setting and exit the Menu.

The setting you chose is put into effect, and the Menu closes. If you need to exit the Menu without changing any of the settings, press

the Clear key. To restore the setting of any menu item to the setting that was in effect when you opened the Menu, press the Reset/Local key (this restores the original setting for the current menu item but does not close the Menu).

The Menu contains the following items (these items are displayed in the order they are listed if you repeatedly press the up-arrow key after opening the Menu):

• REF OSC — Sets the Counter to use the internal timebase or an external timebase connected to the Reference connector on the back panel.

• DO SELF TEST — Starts the sequence of built-in tests.

• BATT VOLTAGE — Displays the current voltage level in the

rechargeable battery packs (only if the Battery option is installed).

• OP HRS — Displays the total number of hours the Counter has bee n in operation since it was last calibrated.

• Model number, firmware version number, serial number, OPTNS (installed options).

• PRESET — Resets all user-settable functions to the factory default settings.

• BAUD — Sets the data rate for the RS-232 serial port.

• FM — Turns the Counter’s ability to compensate for frequency

modulation on (AUTO) or OFF.

• CH1 LPF — Turns the Channel 1 Low -Pass Filte r (approx . 50 KHz) ON or OFF.

• RECALL — Reads and implements a stored set of user settings from one of nine (0 – 9) that are stored in non-volatile memory.

2-40 Operating Guide

Chapter 2 Operating Your Frequency Counter

Using the Menu

• SAVE — Saves a copy of the current user settings in non-volatile memory. Nine sets (0 – 8) can be saved, an d Set 0 is auto matic ally rea d

on startup.

• PWR CORR — Activates (or deactivates) the Power Correction function and allows you to edit and select power-correction profiles. Power Correction is used to compensate for losses in the test configuration, such as attenuation resulting from cable impedance.

Each of these menu items is described in greater detail on the following pages.

Navigating in the Menu and Changing Settings

When you select the Menu (with the Shift and Menu [Reset/Local] keys), the indicator between the arrow keys flashes to indicate that the arrow keys are now active. Since the Reference Oscillator setting is the first one displayed when you invoke the Menu (unless you’ve used the Menu to change another setting since you turned the Counter on), you don’t have to use the up-arrow key or the down-arrow key to get to it.

When you press the right-arrow key, the flashing annunciator ( ) changes direction, and the current setting for the Reference Oscillator INT (internal) or EXT (external) flashes. This indicates that you can now change this setting. Use ei ther the up-arrow key o r the down-arrow key to change the setting.

If there are more than two settings available for the currently selected function, you can cycle through the available settings by repeatedly pressing either the up-arrow key or the down-arrow key. For example, to change the setting for the Baud rate for the serial port, invoke the Menu, and then repeatedly press the up-arrow or down-arrow key until BAUD is shown on the displa y. The n, pres s the ri ght- arrow k ey to se le ct the BAUD option, and press the up- or down-arrow repeatedly until the setting you want is displayed. Finally, press the Enter key to implement your choice.

You navigate to and adjust the remaining settings available in the Menu in the same manner. Each time you modify a setting and press the Enter key, the Menu closes, so you have to reinvoke it each time to change additional settings.

Operating Guide 2-41

Chapter 2 Operating Your Frequency Counter

Using the Menu

Some of the menu items listed on the previous page provide information only (no settings are required [or possible] for these), such as Battery Voltage, Operation Hours, and information that identifies the Counter (HP model number, firmware version number, serial number, and installed option codes). These menu options are described in the

remainder of this chapter and also in “The Front Panel Menus at a Glance” on page 1-4.

NOTE

Always terminate each setting you change in a menu option by pressing the

Enter key. You can abort any change while the Menu is displayed by

pressing the you made to the current menu option, but they do not affect any of the other menu options. The but the Reset/Local key does not.

Reset/Local key or the Clear key. Both keys nullify the change

Clear key terminates the current menu session,

Reference Oscillator (REF OSC)

By default, the Counter uses its internal 10 MHz reference oscillator (or the optional Oven Timebase, Option 001) as a timebase for all

NOTE

measurements, unless REF OSC is set to EXT, and it detects a 1, 2, 5, or 10 MHz reference signal on the Reference connector on the back panel. If an external reference signal is present, you can force the Counter to use the internal reference oscillator by setting the REF OSC menu option to INT.

The available settings are EXT (external) and INT (internal), and the default setting is INT.

When REF OSC is set to internal (INT), the Counter outputs a 10 MHz, 1 V p-p signal on the Reference connector on the back panel.

2-42 Operating Guide

Agilent 53150A Operations Guide

Specifications and Main Features

Frequently Asked Questions

User Manual

In This Guide

Operating Guide Contents and Organization

Related Documents

Types of Service Available if Your Instrument Fails

Standard Repair Services (Worldwide)

Express Repair/Performance Calibration Service (USA Only)

Repair Instrument Yourself

Repackaging for Shipment

Description of the Microwave Fre quency Counter

Options

Hardware

Support

Accessories Supplied and Available

Accessories Supplied

Accessories Available

Manuals Supplied

HP 53150A/151A/152A Quick Reference Guide

The Front Panel at a Glance

The Front Panel Indicators at a Glance

The Front Panel Menus at a Glance

The Display Annunciators at a Glance

The Display Special Characters at a Glance

The Rear Panel at a Glance

Operating the Counter

Turning the Counter On

Turning the Display Backlight Off or On

Using the Menu

Displaying the Menu

Navigating in the Menu and Changing Settings

Setting the Serial Por t Baud Rate (Menu Example)

Selecting the Input Channel

Measuring Frequency

Measuring Relative Frequency

Offsetting a Frequency Measurement

Measuring Power (Channel 2 Only)

Selecting the Unit of Measurement for Power

Measuring Relative Power

Offsetting a Power Measurement

Using Power Correction

Power Correction Theory of Operation

Increasing Profile Accuracy

Selecting a Power-Correction Profile

Entering Data Points in a Power-Correction Profile

Setting the Measurement Rate

Setting the Number of Averages

Setting the Resolution

Introduction

Chapter Summary

How this Counter Works for You

Summary of the Measurement Sequence

Using the Selection Keys

Sequencing Through the Menu

Numeric Entry

Changing States

Using the Clear and Reset/Local Keys

Acknowledging Messages

Other Function Selection Keys

Measuring Frequency

Setting the Resolution and the Measurement Rate

Setting the Resolution

Resolution Setting Exampl e

Setting the Measurement Rate

Rate Setting Example

Setting the Number of Averages

Averages Setting Example

Measuring Relative Frequency

Relative Frequency Example

Offsetting a Frequency Measurement

Frequency Offset Example

Measuring Power

Power Measurement Example

Measuring Relative Power

Relative Power Example

Offsetting a Power Measurement

Power Offset Example

Using Power Correction