anyone use a hp 200CD generator?

[targeteye]

I recently picked up a 200CD generator for general use. After replacing the week 5y3 it seems to be working very well and even accurately calibrated!

The only issue it still has is on the 1k setting the unit will actually audibly emmit the signal between 5K and 6K. It still seems to work correctly but it is sure annoying. I"m thinking the High Freq output transformer may have issues but was curious if anyone else had one of these and could check to see if it does the same thing.

Perhaps its just a characteristic of this model?

Thanks
Steve

[PakProtector]

hey-Hey!!!,
That is afterall an ancient tube amp, so treat it as such. Replace all the electrolytic caps, and any suspect parts you find. Something in the tuning tank drifted and once you find that part or adjustment, you'll be set.
cheers,
Douglas

[Tom Bavis]

Neither of mine make any audible sound. I think it's a loose lamination in the transformer...

[merrylander]

It was over 50 years ago, we used them in Bell for testing and frequency response checks, can't ever remember one making audible noises.

[targeteye]

Thanks for the feedback.

I"ll just avoid 5-6K on that setting. As I can get to those freqs on a lower band.

I might go thru the thing at a later date and rec cap it.

I agree I think its the lamination on the output tranny. (high freq)

Steve

[blue_lateral]

FWfW The manual is here:

http://bama.edebris.com/manuals/hp/200cd/

I have heard of people fixing noisy laminations in power transformers by dipping them in motor varnish or something, with the bolts removed, then tightning it all up before the varnish completely hardens. I can't think of any good reason it shouldn't work with an OPT. I have never done this myself. YMMV.

John

[ultralc]

Don't know anything about this generator, but I have a 50L6 amp from a Magnavox portable record player where the 50L6 tube will act like a speaker (albeit a tiny one) when fed with high level 1KHz test tone. I guess it is the opposite of microphonic.