AL-811HD relay clicking

[KQ4BX]

Can someone suggest what may have caused my amplifier to start clicking the replay, and power pumping on and off as the relay clicks back and forth?

I'm not sure if I over drove it, or what I may have done, nor what went wrong so I can fix it.

I did a search for the symptom, but I knew what I found was not exactly what I describe here.

The amp is out of commission until I get the the bottom of this and fix it.

Thanks for any informed comments?

73' joe

 

[KQ4BX]

What I know now is that the protection circuit is kicking in, and out. I have it powered down and open, tonight I will pull the caps off the tubes, then start adding the tubes back until I find one that may be damaged. I am pretty sure I can run the amp on 3 of the tubes, and I didn't find anything burned, or discolored from heat. That leaves the tubes.

Update: I did damage a tube by running the amp at near full power on D-star. Live and learn, I should have realized that D-star is a digital mode, and other digital modes are run at reduced power.

It looks like I will be ordering at least one 572B in the next day.

 

[cmdrwill]

Yes, something about Duty Cycle, and exceeding it.....

DStar is full carrier and analog modulation, so that will exceed the duty cycle.

 

[KQ4BX]

I took the tubes out and testing them for shorts, then put them back when I found nothing wrong. They are working fine now. Probably just had to cool down and be roughed up a bit.
Live and learn,

Joe