[Boatanchors] Valiant Adustment

[WQ9E at btsnetworks.net]

Paul,

For L-17, see page 10 of your manual.  In brief, set the band switch to 40 meters and tune the VFO to 7.33.  Tune exciter for maximum grid current and set drive for a moderate amount of grid current and adjust L-17 for maximum grid current.

Are you referring to the 100K resistor to ground in the screen circuit of the 6CL6 stage as the missing resistor?  Johnson used the label R61 (and R62) for variable pots for adjusting modulator and final bias which were added to later Valiant production.  

If the 100K resistor is missing and R8 is now effectively 34K I expect the screen voltage is higher than it should be.  There were some revisions in the 6LC6 buffer with the Valiant II where the effective screen series resistor is about 67K (a 120K and 150K in parallel) and the 100K resistor is removed but I am not sure if any running changes were made to the earlier units and 34K of resistance sounds too low.  It sounds like a user mod in your unit.

If you have an early model Valiant it won't have the two variable bias pots.  This change was required if using the Valiant to provide power and modulated plate voltage to the 6N2 transmitter so that the modulator bias is independent of excitation level.  You can find this listed as Valiant bulletin on edebris and the information is also contained in the 6N2 manual.  Although these production change makes bias setup a bit easier there is no need to add this to an earlier Valiant if you are not using it with the 6N2.

Rodger WQ9E

-------- Original Message --------
> From: Paul Baldock <paul at paulbaldock.com>
> Sent: Tuesday, September 27, 2011 6:20 PM
> To: boatanchors at mailman.qth.net
> Subject: [Boatanchors] Valiant Adustment
> 
> Does anybody know the adjustment procedure for L17 in the VFO?
> 
> Also in my Valiant R61 is missing and R8 is 2 68K's in parallel. Was 
> this a factory upgrade for the 6CL6 Buffer?
> 
> Thanks
> 
> - Paul
> 
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