Kris Power Pump?

[broncoman529]

Hi,

I just replaced the tubes that were no good in my Kris Power Pump linear with a 6KV6A driver tube and (2) 6mj6 final tubes. The amp works awesome with 230 peak on AM and 280 peak on SSB. AM mode works flawlessly, But I have a small problem on SSB. When I initially key up on SSB it works fine, But when I stop modulating with the microphone still keyed the amp will not key back up with my voice once the delay drops. It only happens intermittently, But when it does happen I have to unkey the microphone and key back up and speak for the linear to have output. Sometimes if I initially key up on SSB and wait more than a few seconds to talk the amp will not key up unless I unkey and start speaking again. Any thoughts on what might be the problem? Please help me!

Thanks,

 

[paws264]

Hi,

......... Sometimes if I initially key up on SSB and wait more than a few seconds to talk the amp will not key up unless I unkey and start speaking again. Any thoughts on what might be the problem? Please help me!

Thanks,

I am not really sure how much of a real problem this really is versus how much of a problem you perceive it to be.

What you are talking about is the amount of SSB delay designed into the amp (in some amps this is adjustable). The amp is probably operating fine, perhaps you are just speaking too slowly for the RF sensed keyer to stay pulled in.

However, there are 2 active components that could cause keying problems (which you don't seem to have on AM), these are Q1 which acts as a gate for the voltage that travels thru it to R3 which is the voltage that turns Q2 on and off which is what activates the antenna switch relay (RL-1).


You could also place a higher value capacitor in the C6 position, that might give you more hold in time.

.

 

[paws264]

Or, you could just turn your power mic wide open, that will keep the SSB keyed up on your amp.


.