[Johnson] Viking II low modulation

[Gary Schafer]

That is a step down transformer in the driver. They need a low impedance 
at the grids because the modulators run in AB2 and draw grid current.

Measure the audio voltage at the grids with a scope. See if it exceeds 
the biase voltage slightly. If it does then the transformer is probably ok.

73
Gary  K4FMX

Michael Sell wrote:
> I am modifying a Viking II for a friend.  It had very low modulation.  Was
> that way before I began and even after a complete rebuild of the speech amp.
> I suspect the inter-state transformer, T3. Lot's of audio goes in, not much
> out to the 807's. However, the ohm meter measurements do match what the
> manual says they should be on the original transformer.  Any idea's.
> 
> I used a replacement from AES back in 1998 to fix my VIking II but it is no
> longer available.  (thordarson 20A14)  Any idea's where to find a
> replacement?
> 
> Michael Sell
> k0com at comcast.net
> 
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