[Johnson] My poor sick Viking II

[Gary Schafer]

Do these things then let us know the results:

1.  While tuning up and the plate current starts to rise, can you retune 
the plate tuning and bring it back down momentarily?

2.  Watch the grid current when the plate current starts to rise 
(quickly switch the meter to grid current). What does it do?

3.  Can you turn down the drive control and make the plate current drop 
to what value?

4.  What band are you trying to use?

5.  Have you tried with a crystal instead of the vfo?

73
Gary  K4FMX


KENNETH A CRIPS wrote:
> I have been watching My Viking II transmit while dumping it's output into a
> cantenna trying to track down the fuse blowing problem.  I replaced the 
> 807's
> one was gassy, the other was weak. I pulled out all of the 6146 (not A, B, 
> or W)
> I had and tested for the two best ones. Here is what I witnessed.
> The transmitter was in CW mode, 160 meter coil switched out, M122 VFO 
> installed.
> I started into the tune up and the PLT  dips where coming at the correct 
> places
> for the frequency I was set at. I made sure the PLT reading never went above 
> 250 mills.
> as I approached the tuning peak the meter started to slowly raise. I had 
> lots of fuses so I watched the tubes to see if anything happened. I had a 
> R390A on the frequency the
> transmitter was tuned to.  I noticed a increasingly loud buzz, and at the 
> same time
> one of the 6146's started to arc inside and with in a second or two the fuse 
> would blow.
> I changed out the 6146 that was arcing and started again the same thing 
> happened except this time the tube that I had not changed arced over. I am 
> going to check the clamp
> circuit on the Viking again I set it up and it should be ok, but who knows 
> with old gear like this.
> 
> Do any of you have any ideas what is going on here.
> 
>                    Ken de W7ITc 
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