Just a couple of initial questions for now: Can these things be repaired? What internally is it that actually fails. I have an 8664A signal generator (and the aching back to prove it!) that has "gaps" in the output level as it is varied from the front panel. The transitions from/to sensible output to/from just noise coincide with audible relay clocks in one of the 2 attenuators. With the top cover off, and if my 65yo ears aren't deceiving me, it's the 33321-60030. Before rolling up my sleeves and doing any further disassembly to remove/replace/inspect the attenuator, I'm just wondering if they can actually be repaired with a sensible level of effort. Replacements can be had on eBay, but I suspect it's just a crap shoot as to whether any of those would be in better working order than my own. The sig gen otherwise works fine, and I can get by output-level-wise with the presently functioning range of the internal attenuators combined with fixed external attenuators. But if the internal one can be fixed, I'd like to invest the time and do so.
Thanks,
Jim