[Boatanchors] SG-8 Sig Gen, Band "E" Fudgy

[Glen Zook]

Don't trust a tube tester, especially since the tube tester checks at DC and cannot test a tube as an oscillator at like 100 MHz!

Try a couple of different tubes in the oscillator and then see what happens.
 
Glen, K9STH


Website:  http://k9sth.com
On Wednesday, April 16, 2014 2:01 PM, "digital-conjurers at roadrunner.com" <digital-conjurers at roadrunner.com> wrote:
 
No answers from other groups (incl. Heath), thought someone here might know....

Got this SG-8 out of 5-year storage, cleaned it up, lubed/cleaned the 
switches, pots, tested the tubes, etc etc.....and it all works fairly well 
for what is it...but Band "E" is extremely erratic.  A thru D are fine.

Have tried numerous fixes, tightened ground bolts, touched up fudgy solder 
joints....no go.  Can sometimes get a squawk out of it around 40 Mhz or 
so... _ if I happen to bend the coil sub-chassis a bit towards the front 
panel_....but it's very unreliable, not a permie fix.

Switched tubes, too, just for grins...no luck.

Clue: The fellow who had this before me put in a 1Meg ohm pot in the audio 
gain position _with no on/off switch_ (orig. was 1 meg too)...can hardly 
see how this could affect the case, but...that band "E" is nasty...all it 
used is the bus bars for inductance, methinks.

Anyone have a similar issue and fix it with this generator?

All tubes tested fine on a Hickok 539B.

Tnx,

Lin/KJ6EF 
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