Viking II puzzler

[Paul Litwinovich]

TNX to all that replied. I finally found the problem. the rig has a .01uF 1.5kv disc cap between the plates of the 807s. It tested good for value and leakage but was braking down under modulation peaks. After replacing it with a cap with a 3kv rating I decided to perform the same test that we do on broadcast rigs, feed the set a 1khz square wave@ 50%modulation and look at the overall response. I saw quite a bit of ringing. I optimized the system with a snubber composed of the .01uF cap and a 2.7k 5w non inductive resistor. nice response between 300 and 3khz with no overshoots or ringing.
73
Paul A.Litwinovich
Chief Engineer
WSHU AM&FM, WSUF FM
N1MUC
"RF IS GOOD FOR YOU"