Wavetek 143 - Page 23

5.1 FACTORY REPAIR
Wavetek maintains a factory repair department for those
customers not possessing the necessary personnel or test
equipment to maintain the instrument. If an instrument is
returned to the factory for calibration or repair, a detailed
description of the specific problem should be attached to
minimize turnaround time.
5.2 REQUIRED TEST EQUIPMENT
Voltmeter ο... 0.1 mVdc resolution (0.1% accuracy)
Oscilloscope, Dual Channel. . . . .. 2 150 MHz bandwidth
Distortion Analyzer e To 600 kHz
Counter aa: To 20 MHz (0.1% accuracy)
БОС osd A +0.1% accuracy, 2W
Generator о: 200 kHz signal, 2 to 20V p-p
5.3 REMOVING GENERATOR COVERS
de Invert the instrument, remove the four screws in the
cover.
2 Turn the instrument upright, remove the top cover,
and remove the four screws securing the bottom cover.
3% Replace the top cover and turn the instrument upside
down.
NOTE
Remove the bottom cover only when it is neces-
sary to make adjustments or measurements.
5.4 CALIBRATION
After referring to the following preliminary data, perform
calibration, as necessary, per table 5-1. If performing partial
SECTION
CALIBRATION
calibration, check previous settings and adjustments for
applicability. See figures 5-1 and 5-2 for calibration point
location.
1. Unless otherwise noted, all measurements made at the
50Q OUT connector should be terminated into а 500,
(50.196) load.
2: Verify operation in TRIG and GATE modes by con-
necting an external generator to the TRIG IN BNC
and observing proper operation of TRIGGER LEVEL
and TRIGGER START/STOP controls (paragraph 3.1).
3. Verify SYNC OUT is an approximate 30 ns positive
pulse into 500 and that GCV OUT is a voltage pro-
portional to dial position with a2V max (open circuit).
4. Start the calibration by connecting the unit to an ac
source and setting the front panel switches as follows:
Dial rex mE AE RN pe ҒА A SAY .02
BREO: MULT on dude ος) 100K
FREQ МЕНМЕН ее 8 Full cw
GENERATORIMOD Es I 05] ELT CONT
RISER Ell Е Full cow
TRIGGER STARTS LOL 20077 SERIE 0° CAL
ЗҮММЕТНҮ л СТ E ee es eee OFF
5ο ΘΕΕΘΕΤΟΕ ЫЛ О eee ORTE. OFF
FUNGTIONES 8 DC
ATTENUATION 22-22 52722225 57226225 7270 2010
ATTENUATION VERN IE... Full cow
POWER 25 265 RT Lot ee ya ON
5. Allow the unit to warm up at least 30 minutes for
final calibration. Keep the instrument covers on to
maintain heat. Remove covers only to make adjust-
ments or measurements.
5-1