Re: HP8640B Signal Generator
Here's a progress report folks. There are a few fairly major problems remaining. The A9 assembly is now detached and two of the three rotary switches have only a single spring contact. Only a couple of plastic gears need intensive care and maybe one or two just a spot of glue. The FM slide switch is sticky but seems OK. The AM slide switch is now detached and waiting for inspiration to fit a new lever. The attenuator knob has so far refused all attempts to come off and needs a new printed scale. The multi-turn tuning mechanism needs a tiny adjustment and some scalpel work in-situ on the inner plastic disk. The output amplifier is awaiting further experiments which I'm putting on hold until the range can be moved from 4-8MHz where it's stuck until A9 faults are cleared.
Fortunately, most if not all the problems, seem to be stock faults and have been described with lots of helpful suggestions and pictures.
I see a late mod is adding buffers under the transparent top of the mode switches.
Allan
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