"KNX" Screen Mod and Viking II an Clamper Tube

[ka2pbo]

 I was just wondering if anyone has done the "KNX" Screen mod on a Viking II and what changes had to be made to the clamper tube circuitry ; if any. Im assuming the rig wont do CW anymore without some sort of external switching or fixed bias.

 Thanks

   Rick

[wa3dsp]

Rick,

  That is exactly what I did on the Ranger which is very similar to the viking in regard to the clamp tube. I kept the clamp tube and simply used the KNX mod with it. I also used variable bias on the clamp tube to vary the transmit power. It still clamps and works fine on CW or if there is loss of drive.

See the schematic at my site on the Ranger mod for details.

http://www.crompton.com/hamradio/JohnsonRanger/RangerRestoration.html

[ka2pbo]

Thanks Doug ,

If I would have looked at the modulator modifications schematic on your Ranger page the first time I was there I would have seen it ! Nice job...should work fine for me !

 73

  Rick