Hi all, I have gotten in my hands a 'semi' working IEC F34 Function Generator. The problem is that it does not in any shape or form have a stable waveform. Usually there is a lot of amplitude modulation on the signal. 3 Doors Down Better Life Zip more. Law of electronics repair #1: 'Thou shalt check voltages.' Luckily, this device is from the early 70s!

FUNCTION GENERATOR MODEL 5400ACR3 SfRIAL No3a OPERATING AND MAINTENANCE MANUAL KROHN-HITE CORPORATION 580 Massachusetts Ave., Cambridge, Mass. FUNCTION GENERATOR Operation Manual. 8110 FUNCTION GENERATOR ii. Bench type function generator capable of producing 5 different waveforms. • Meets IEC-1010-1.

When they still knew hot to put nice pretty test points in everywhere. (And the manual is awesome.) Manual is attached. Anyway, it has a split supply +-15 and +- 5 V.

Both positive rails are dead on, but the negative 15V rail measures -12.## and the -5 measures -4.5. So, I checked the manual (attached), and it says 'Q31 or Q32 shorted' for the problem of '-5V rail too high.' Technically the -5V rail is too 'high', but it all depends on what you consider high with negative numbers. The other problem of '-5V rail too low' is simply Q31 or Q32 open'. Neither of which is true. I don't know how a transistor can be shorted, but both had 10s of kOhms between the pins.