PRAXSYM 5500, 5700 User Manual

PRAXSYM

Model 5500 Receiver

Model 5700 Transmitter

User’s Manual

February 6, 2002

TABLE OF CONTENTS

1.0 Overview of Model 5500 Receiver page 3

2.0 Operation of Model 5500 Receiver page 4

2.1 Control and Indicator Description page 4

2.2 Battery Charging page 5

2.3 Operation with AA Dry Cells page 6

3.0 Making Path Loss Measurements page 7

4.0 Controlling the Receiver Remotely page 7

5.0 Definition of Receiver Commands and Error Codes page 8

6.0 Overview of Model 5700 Transmitter page 11

7.0 Operation of Model 5700 Transmitter page 11

7.1 Control and Indicator Description page 11

7.2 Battery Charging page 13

7.3 Operation with AA Dry Cells page 13

7.4 Operation with External Power Source page 14

8.0 Programming the Synthesizer page 14

8.1 Programming Through a PC page 14

8.2 Programming Through the Model 5500 Receiver page 15

9.0 Definition of Transmitter Commands and Error Codes page 16

Appendix A - RXScan Software page 18

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MODEL 5500

DUAL BAND SIGNAL STRENGTH RECEIVER

USER MANUAL

Overview of Model 5500

1.0

The Model 5500 Signal Strength Receiver is a portable, dual band receiver that measures the strength of
an RF signal. The receiver is capable of measuring signal strengths from -20dBm to -120dBm. The
frequency and signal strength are displayed on the LCD display on the front panel or can be monitored
remotely over an RS232 interface. The receiver and transmitter frequency can be set using the keypad
on the front panel of the receiver or controlled remotely.

These Model 5500 Dual Band Receivers are available:

Part Number Low Band High Band

310-010055-002 Cellular band (824 – 894 MHz) PCS band (1930 – 1990 MHz)
310-010055-003 GSM band (925 – 960 MHz) DCS band (1805 – 1880 MHz)

The Dual Band Receiver can be used in conjunction with Praxsym’s Model 5700 Dual Band
Transmitter to take path loss measurements in the low band (Cell or GSM) and high band (PCS or
DCS). Typically, the operator decides which frequency to use for testing by scanning the band with the
receiver, identifying vacant frequencies. Once the test frequency is determined, the appropriate
Transmitter Synthesizer Assembly is programmed with the transmit frequency for the test.

Note: If your receiver is the Cellular/PCS model, the term ‘low band’ will refer to the Cellular band and
‘high band’ will refer to the PCS band. Likewise, in the GSM/DCS model, the term ‘low band’ will refer
to the GSM band and ‘high band’ will refer to the DCS band.

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2.0

Operation of the Model 5500 Receiver

2.1 Control and Indicator Description

See the following figure for the connections and control locations.

Communications port

Shipping switch

Key Name Key Function

ON Press the ‘ON’ key to turn the unit on. The display will indicate the receiver status.

OFF Press the ‘CTRL’ and ‘OFF’ keys simultaneously to turn the unit off.

BAND

Press the ‘CTRL’ and ‘BAND’ keys simultaneously to toggle the receiver between
the low and high bands. The display will indicate the active band, and the last tuned
frequency in that band.

FREQ

Press the ‘CTRL’ and ‘FREQ-UP-ARROW’ keys simultaneously to increment the
receiver frequency up by one step. If these keys are held for more than ½ second,
the frequency will be changed at 10 times the rate, allowing rapid slewing across the
band. ‘CTRL’ and ‘FREQ-DN-ARROW’ moves the tuned frequency down.

LIGHT Press the ‘LIGHT’ key to toggle the display backlight on and off.

CTRL This key is used in conjunction with certain other keys to help prevent accidental

activation.

F1

Reserved

F2 Press the ‘CTRL’ and ‘F2’ keys simultaneously to put the receiver in “TX Program

Mode.”

Model 5500 Dual Band Receiver

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Received Signal Strength

Synthesizer Lock Status

Receiver

Frequency

Battery Charge State

Active
Band

Indicator Function

Received Signal Strength Indicates the signal strength of the channel the Receiver is currently tuned

Receiver Frequency Indicates the frequency of the channel the Receiver is tuned to receive.

Active Band Indicates the active frequency band.

Synthesizer Lock Status Indicates the lock status of the Synthesizer PLL. When the padlock is

Battery Charge State Indicates the current charge state of the batteries.

Connection Function

Shipping Switch The shipping switch should be placed in the OFF position whenever the

Communications Port RJ45 modular jack for serial communications to the receiver. See Sections

Charger Jack Jack for connection to 9V AC/DC adapter for battery charging. See

Low RF Input Connector TNC connector for low band antenna
High RF Input Connector SMA connector for high band antenna

2.2 Battery Charging

The Dual Band Receiver is fully operational while the batteries are being charged. Charging
can occur whether or not the unit is powered on. However, with the unit powered off, there
will be no way to monitor the charge cycle.

When the display shows “BATTERY LOW”, the battery has less than 10% of its maximum
capacity remaining. Connect the AC/DC adapter (9V /300mA) to the unit’s CHARGE jack.
Plug the adapter into a 115V 60 Hz power outlet. An internal battery charger will control
and terminate the charging of the 4 NiMH cells within each unit. Allow about three hours
to fully charge the batteries.

A.) The charge cycle begins in the charge pending phase. For a period of time, the battery

-110 dBm

Freq:
Band:

to receive.

closed, the synthesizer is locked.

receiver is placed in the case. The switch prevents discharge of the
batteries should the ON key on the front panel be inadvertently pressed.

4.0 and 5.0.

Section 2.2.

display area may alternate between displaying the normal battery bar and the message

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“CHARGING.” During this time, the charging circuitry is conditioning the battery
before entering the fast charge phase.

B.) In the fast charge phase, the message “CHARGING” appears on the display. The time

to achieve a full charge will depend upon the amount of charge remaining on the
battery.

C.) Once the batteries are fully charged, the message “CHARGING” is replaced by charge

bar. In this mode the battery charger will maintain battery charge using a pulse trickle
mode as long as the adapter is plugged into the Battery Box.

If the AC/DC adapter is connected while the Receiver is in operation and after the batteries
have discharged below 4 volts, the charger will remain in the charge pending phase. The
batteries will continue to discharge since the unit’s operating current is greater than the pulse
trickle charge rate. When this condition occurs, turn the unit off until the batteries have
charged to the point that the fast charge phase begins. The unit may then be turned back
on.

2.3 Operation with AA Dry Cells

Although the four internal AA Nickel Metal Hydride (NiMH) batteries should provide
sufficient power for most testing situations, provision for operation with disposable lead acid
or alkaline batteries has been made.

A. With the unit off and unplugged from the wall adapter, remove the four #8 screws

from the back of the receiver. Remove the lid.

B. Fully remove the batteries in the holder.

C. Install the new batteries and reinstall the lid and screws.

• If the 5500 Receiver will be operated for periods of greater than 6 hours, it is

recommended that the AC/DC adapter be connected to the unit.

• The AC/DC Adapter should only be used while the rechargeable batteries are

present in the unit.

NOTES

• Do not attempt to use the adapter when disposable batteries are installed

in the unit.

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3.0

Making Path Loss Measurements

The Model 5500 Receiver measures absolute signal strength of CW signals at the antenna input port. Relative
path loss measurements can easily be made by selecting a reference location and then moving the receiver to
different locations while noting the change in received signal strength. To measure actual path loss, the user
must take into account the gain of the antennas being used on both the transmitter and receiver and the output
power of the transmitter.

The Model 5500 Receiver is a single conversion receiver with an intermediate frequency of 90MHz. Because of
the bandwidth of the SAW filter, there is very little attenuation of signals in the adjacent channel (30 kHz).
Signals that are 60kHz from the receiver frequency are attenuated by more than 40dB. Because of this
limitation, the user should not conduct tests in a channel adjacent to a strong signal.

When using the receiver with the Model 5700 Transmitter, the following procedure can be used to setup the
equipment to make relative path loss measurements.

• Install the supplied cable between a serial port on the PC/laptop and the serial port on the

receiver.

• Install the antenna for the proper band and turn the receiver on.

• Start the RXScan software. Enter the frequencies or channels that you would like to scan and

then initiate the scan. Information on controlling the receiver with the RXScan software can be
found in appendix A.

• Using the spectrum display or the spreadsheet output of the RXScan software,

choose a test frequency. Tune the receiver to the test frequency.

• Set up the test transmitter to the test frequency using the procedures outlined in Section 8 of this

manual. The RXScan software can also be used to set up the transmitter. See Appendix A of
this document.

• Install the 30dB attenuator on the RF OUT port of the test transmitter. (An attenuator is

provided when the Receiver and Transmitter are purchased as a system). Connect a coax cable
from the attenuator to the antenna input of the receiver for the correct band. Caution: Always

use the attenuator when connecting the transmitter directly to the receiver. Too much
RF power applied to the receiver could damage the low noise amplifier.

• Adjust the AMPL ADJ control on the transmitter until the receiver measures 30dB lower then

the output power you would like at the transmitter antenna base.

• Connect the test transmitter to the test antenna.

• Begin path loss measurements.

Controlling the Receiver Remotely

4.0

The receiver can be controlled by a PC or embedded controller via the RS232 interface. The RXScan software
included with the receiver can be used to control the receiver for most applications. Procedures in this section
also describe control with terminal emulation software on a PC or laptop computer.

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