[Boatanchors] SG-8 Sig Gen, Band "E" Fudgy
gzook at yahoo.com
Thu Apr 17 11:41:48 EDT 2014
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.
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.
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