[AMRadio] Viking II Audio Mod Question

[Gary Schafer]

I think that the Valiant or maybe the Ranger has a similar audio circuit with
the parallel 12AU7 driver.

73
Gary


"Freeberg, Scott (STP)" wrote:

> Hi,
>
> I am cleaning up a recently acquired Viking II and discovered the original
> audio circuits had been totally removed, including tubes and sockets.  They
> were replaced with 9 pin sockets and a 12AT7 and a 12 AU7.  The first tube
> is used as a two stage preamplifier with the second stage (of the first
> tube) driving paralleled grids of second tube.  The second tube is all
> paralleled.  The plates are tied together driving the audio interstage
> transformer, the grids are tied together, and the cathodes are tied
> together.   Does this mod sound familar with anyone?  I'd like to get
> additional information to confirm the value of the input resistor and the
> wiring.  I don't know if this mod originally worked or is even wired up
> right, so I'd like to find out more about it.  I'm half inclined to rip it
> out and restore the Viking II back to the original configuration.
>
> By the way, 75 meter AM has been great these past few days.  I wuz on last
> night and checked into the South Eastern AMI net and the informal rag chew
> afterwards and all the guys were sounding great up here in Saint Paul
> Minnesota.  Even the low power AM rigs were running S-9 to 10/S9.  I sure
> want to enjoy 75 while its so quiet in the winter because we all know what
> it sounds like in the summer....
>
> 73,  Scott WA9WFA in Saint Paul Minn
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