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BE FM 3.5B problem

greg.hahn said:
wvnrwnyv said:
IF amperage: ~.95 (now at .17)
Plate Current: ~4300 (now at 3.0)
Percent Power: ~98-100 (now at 2.0)

My GM went up to the transmitter today and said the meters read barely any amperage or plate current.
Click to expand...

Up to now everyone has failed to mention that you are basically off the air. The reason you hear static in your signal is that you have no output power.

I interpret your normal readings to be:

Ip (Plate Current) .95
Ep (Plate voltage) 4300

That would give a DC input power of 4085 watts. If we assume typical 76% efficiency, your total power out would be 3100 watts. That sounds about right for a 3.5 KW tube type transmitter. Does that sound right to you?

But you are saying plate voltage has dropped to 3 volts, and plate current to near nothing, and your RF output meter to zero. YOU'RE OFF THE AIR!!! Whatever you are hearing now is your exciter and possibly your IPA stage coupling through the dead tube stage to the antenna. You may have a couple of watts, that's it.

Now, forget everyone's advice here, except the ones that told you to get an engineer in there. You need someone that knows waht he's doing!
Click to expand...

I 1000% agree!! If you don't know what you are doing, GET AN ENGINEER IN THERE! You could kill yourself screwing around without knowing what you are doing!
 
Yes, we're trying to reach our engineer, I think we have reached him now we just need to get up to the transmitter with him. The odd thing is that while I was in Poultney VT a good 8 miles from our FM Transmitter I could hear it clearly with only minor static intermediately. hmmm...
 
wvnrwnyv said:
Yes, we're trying to reach our engineer, I think we have reached him now we just need to get up to the transmitter with him. The odd thing is that while I was in Poultney VT a good 8 miles from our FM Transmitter I could hear it clearly with only minor static intermediately. hmmm...
Click to expand...

You were hearing the exciter loosely coupled through the tube to the antenna.
 
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