Hameg HM 303-4 Service Manual

ENGLISH 4S-0303-04E0 10 JUN 1998

Instruments

Oscilloscope

HM 303-4

SERVICE-MANUAL HM303-4

Table of contents

Service Manual Circuit Diagrams Adjustment Procedure

HM303-4

Y-Preamplifier CH I (YP-Board).................................. 4

Y-Preamplifier CH II (YP-Board)................................. 5

Y-Intermediate Amplifier and Trigger Amplifier

(YP-Board) ................................................................. 6

YPA-Board (Top side)................................................. 7

YPA-Board (Bottom side) .......................................... 8

XY-Amplifier, YF-Amplifier, OS-Circuit ....................... 9

XY-Board (Top side) ................................................. 10

XY-Board (Bottom side)........................................... 11

Sync.-Amplifier........................................................ 12

Time base................................................................ 13

Sweep-Generator .................................................... 14

TB-Board ................................................................. 15

CRT-Board ............................................................... 16

CRT-Board (Top and Bottom side) ........................... 17

Power Supply (PS-Board)........................................ 18

PS-Board (Top side)................................................. 19

PS-Board (Bottom side) .......................................... 20

Component tester, Calibrator .................................. 21

CCT-Board (Top and Bottom side) ........................... 22

Front-Control Board................................................. 23

Front-Control Board (Top and Bottom side) ............ 24

ADJUSTMENT PROCEDURE ................................. 25

St. 100698. Hüb/goRR

Subject to change without notice

Specifications

Vertical Deflection

Operating modes: Channel I or II separate,

both Channels (alternated or chopped), (Chopper frequency approx. 0.5MHz). Sum or difference with Ch. I and Ch. II (both channels invertable).

XY-Mode: via channel I and channel II Frequency range: 2xDC to 30MHz (−3dB)

Risetime: <12ns. Overshoot ≤1%. Deflection coefficients: 12 calibrated steps from 5mV/div. to 20V/div. (1-2-5 sequence) with variable 2.5:1 up to 50V/div. Accuracy in calibrated position: ±3% Y-expansion x5 (calibrated) to 1mV/div. (±5%) in the frequency range from DC - 10MHz (–3dB) Input impedance: 1MΩ II 20pF. Input coupling: DC-AC-GD (ground). Input voltage: max. 400V (DC + peak AC).

Triggering

Automatic: (peak to peak) <20Hz-100MHz (≤ 0.5div.) Normal with level control: DC-100MHz (≤0.5div.) ALT. Triggering; LED indicator for trigger action

Slope: positive or negative, Sources: Channel I or II, CH. I alternating CH II,

Coupling: AC (10Hz to 100MHz),

Active TV-Sync-Separator (pos. and neg.) External: ≥0.3

Time coefficients: 20 calibrated steps

from 0.2s/div. - 0.1µs/div. in 1-2-5 sequence Accuracy in calibrated position: ±3%. Min. speed incl. variable 2.5:1 up to 0.5s/div. with X-Mag. x10: ±5%; 10ns/div.: ±8%

Holdoff time: variable to approx. 10:1 Bandwidth X-amplifier: 0-3MHz (−3dB).

Input X-Amplifier via Channel II, (sensitivity see Channel II specification)

X-Y phase shift: <3° below 220kHz.

Test voltage: approx. 6V Test current: approx. 5mA Test frequency: approx. 50Hz

Test connection: 2 banana jacks 4mm ∅ One test lead is grounded (Safety Earth)

CRT: D14-364GY/123 or ER151-GH/-, 6" rectangular screen (8x10cm) internal graticule

Acceleration voltage: approx 2000V Trace rotation: adjustable on front panel Calibrator: square-wave generator (tr <4ns)

≈1kHz / 1MHz; Output: 0.2V ±1% and 2V Line voltage: 100-240V AC ±10%, 50/60Hz Power consumption: approx. 36 Watt at 50Hz. Min./Max. ambient temperature: 0°C...+40°C Protective system: Safety class I (IEC 1010-1) Weight: approx. 5.6kg, color: techno-brown Cabinet: W 285, H 125, D 380 mm Lockable tilt handle

line, external

DC (0 to 100MHz), LF (0 to 1.5kHz)

from 30Hz to 30MHz

p-p

Horizontal Deflection

Component Tester

rms

General Information

(open circuit).

(shorted).

OSCILLOSCOPES

30MHz Standard Oscilloscope HM303

Dual Channel, DC to 30MHz, 1mV/div.; Overscan Indicator Time Base: 0.2s to 10ns/div.; Variable Holdoff; Alternate Triggering Triggering: DC-100MHz; Auto Peak to Peak; Active TV-Sync-Separator Additional Features: Component Tester, 1kHz/1MHz Calibrator

The new HAMEG HM303 oscilloscope succeeds the HM203 (over 170,000 sold worldwide). The bandwidth has been extended from 20 to 30MHz , the sweep rate increased to 10ns/div. and improvements added to the already legendary HAMEG auto triggering system. The HM303 is the ideal instrument for waveform display in the DC to 100MHz frequency range.

A key feature of this oscilloscope is the vertical amplifier's pulse fidelity, limiting overshoot to only 1%. The HM303 offers a special fast rise time 1kHz/1MHz Calibrator, permitting high quality probe compensation across the entire frequency range to ensure probe-tip thru to display integrity. An Overscan Indicator assists in vertical display amplitude and position adjustment.

The HM303 is capable of triggering on input waveforms over 100MHz and on signal levels as small as 0.5 division. Alternate triggering mode enables the display of two asynchronous signals simultaneously. An active Video Sync- Separator permits detailed examination of complex TV signal inputs. A well proven, built-in component tester is now equipped with a stabilized measuring voltage. The use of a switching type of power supply minimizes both weight and power consumption and universally accepts a wide range of input power line voltages, without the requirement to change jumpers or switch positions. The

HM303's CRT is fully mu-metal shielded against outside magnetic fields.

HAMEG is setting new price/performance breakthroughs with the introduction

of this fine oscilloscope. This performance packed scope will tempt all users to run it through its paces.

Screen photo of 50 and 100MHz

Screen photo of 1 MHz square wave signal

sine wave with alternate triggering

Subject to change without notice

5/96

Accessories supplied: Line cord, Operators Manual, 2 Probes 1:1/10:1