[TenTec] Omni VI Pls CW hum

[Ken Brown]

Jorge,

Since you have made adjustments to PA circuitry, I am guessing that you 
hear this hum on your sidetone during transmit? Maybe it is a power 
supply problem. Perhaps the filter capacitors are going bad or the diode 
bridge has a failed diode. What happens when you transmit at very low 
power? Is the amplitude of the hum dependant on the amount of current 
being drawn from the power supply? Can you try a different power supply? 
How about paralleling a big fat umpteen thousand microfarad capacitor 
across the DC power supply line? Does this change anything?

DE N6KB

>My Omni VI pls has recently developed  an intermittent
>hum which can be heard through  headphones while on CW
>mode. I did the current limiting and power amplifier
>bias adjustments, hoping that either would solve the
>problem but no luck.
>Looks like the problem has to do with the DC input
>board, Has anyone has a similar problem.
>
>  
>