[AMRadio] Viking Desk Modulation

Jay Bromley jayw5jay at gmail.com
Tue Jan 15 01:02:46 EST 2008

It has been a long time since I owned one, but be sure to look for the 
obvious things like wrong regulator tube in wrong socket.  Check bias and 
screen voltages, but use great care!  My mod iron had two taps, one would 
make slightly more than 100%, but required more audio drive.

I am not sure what your audio driver is, but it make not be up to the task.

Wow what a nice gift!!  Have fun and enjoy, you will get it iron out.  73 de 

Hello All, I recently inherited a Viking Desk Kilowatt from a SK friend of 
mine. I returned it to service after almost a year. It seems to make output 
power 275 low power and +700 watts high power. When looking at the 
modulation on a scope though it appears to be only modulating about 80% in 
either low or high power.
I have changed out the 810's and 4-400 and see little improvement. I do 
notice that when I approach 80% modulation on the scope that both positive 
and negative peaks appear to curl slightly instead of going flat like I 
thought I would see with clipping.  Anyone have any thoughts or experience 
on where to look next ?

-Tom / KA1NVZ
Anchorage, Alaska

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