[Johnson] Viking Desk Modulation

[Tom Elmore]

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