Audio Pot Replacement for Viking II

[W7POW]

Hello everyone.  First post here on the  forum.  I just scored a Viking II locally and it seems to be in good shape.  Looks like someone added the PTT mod and am currently replacing the paper caps and the electrolytics.  The audio pot was replaced by someone in the past but they used a wimpy one with a two inch shaft and it is burned up.  Any suggestions on a replacement?  Also, the knob is missing as well.  Anyone know where I can get a replacement knob?  I am really excited about getting this rig up and running again and this will be my first AM rig.  Thanks everyone.
73,
Chris Simmonds

[kA5WHO]

Hi Chris
  I can send you a knob
dale

[W7POW]

Dale,
That would be great!!!  Let me know what I owe you and I will PM you my address.  Thanks a million.

I was digging through my junk box and the only suitable pot rated at 2 watts that I own is a 300K Linear.  What would be the effect of using this temporarily until I can find a 1 meg pot??

73 to all!

[WD5JKO]

  Chris, using that 300K would lower the gain, and attenuate the bass more than stock if C2 is still 0.003uf. The modulator would still work though (somewhat), while waiting for a replacement.

   I'm trying to figure out how that pot smoked. Even if cap C2 shorted, I don't see the pot smoking. What does happen with the Viking I, II is that people try different tubes replacing V2 with maybe a 6AH6 to get more drive. If someone tried a 6C4, a triode, then pins 1,5 are tied together. This would smoke the pot as the wiper is turned down since the LV B+ gets shorted out through the pot. Make sure the tubes in there are what Johnson says they should be. You can do mods later..

Jim
WD5JKO

[W7POW]

Brian,
Your probably right about someone replacing the old one due to age with a cheapy RS replacement. 

Jim,
thanks for the insight.  The tubes are all correct other that they had a 5R4 where the 5V4 should have been and 5U4 where one of the 5R4 should have been

Chris.