[Milsurplus] More Vodka-Scented Ether (long)

[David's Mail]

Original Message ----- 
From: "Meir WF2U" <wf2u at starband.net>
> Regarding caps in Russian equipment - I never had a bad cap (excluding
> electrolytics) in any Russian equipment I own, and never had a cap failing
> at the rated supply voltage. Their caps are constructed using a different
> technology that is not prone to deteriorate and short out....
> Feeding the US-P with 150-160 V should be safe, even if you don't want to
> apply the full rated 200V.

Thank you for writing, Meir, and for sharing your superior
knowledge of these radios.
I'm confident you're correct about the caps.
The higher voltage would likely work, but it isn't needed to
make the receiver perform in a manner I find acceptable.
I believe I lose a minor amount of performance,
but gain better preservation
by using as little B+ as possible.
Moreover- it's safer for me, because I'm clumsy.
My fingers keep forgetting that electrons hurt.
I've already been "bitten" by the 60 volts once.
Had I been running 200 volts, it might have been nasty.

>.... Also, the tube socket contacts are
> intermittent sometimes (contact material quality) and ground rivets/srews
> should be checked for good ground contact.

I forgot to mention in the post
that I did find two grounding screws and nuts which
had come loose- one in the tuning cap, one that provided ground to
the interesting mounting strip along the "audio" side of the rig.
I'll check for more.  And thanks for the tip on the resistors.
If I find a bad component, I'll lift one end, leaving it in place
and "tack-solder" in a replacement.
Another thing I forgot to include: The audio output is derived using
an audio choke with a cap coming off a center-tap.
the half between the output cap and the audio tube is open.
I tacked-in a 3300 ohm resistor across the open winding
and that restored function.

73 Dave S.