Need Help

[HillBilly]

have a 6 tube modulator that keys 75 watts with 2 watts on the radio dk the with 30 watt swing it goes to a full amazing 15 watts put of the box. I NEED HELP!!!!

[Popcorn501]

A 6 tube mod???? Who makes it? And what kind of tubes are in it? So you are dead keying 2 watts into the mod and you are only see a 15 watt swing???

[HillBilly]

It is a homemade box. It has 6 12dq6B's in it. The radio is keying 2 swinging 35. The box keys 75 swings 15.

[HillBilly]

When i first got it it would do about 500 on my rms meter.

[kor b]

It is a homemade box. It has 6 12dq6B's in it. The radio is keying 2 swinging 35. The box keys 75 swings 15


.

Is this backward swing? If so the problem could be your are coming up short on amps or you need to do some grounding.

[Popcorn501]

Yeah sounds like you got something going on there.Id try checking all my grounds and jumpers

[HillBilly]

Well the other day we had a power surge and it popped 4 of the tubes and i put 6 new ones in it and let them sit for the 24 hour burn in and it still does it.

[Night Crawler]

Well the other day we had a power surge and it popped 4 of the tubes and i put 6 new ones in it and let them sit for the 24 hour burn in and it still does it.

You popped something in your High Voltage supply too.
Check your HV Rectifiers and Filter Capacitors.

[Trouble]

Check your HV Rectifiers and Filter Capacitors.

This one has my vote being that the tubes are new. Replaced with same type tubes also?

[Foxhunter]

How/what do the remaining tubes test at ? I see that it's important that the tubes be of pretty close equal output and not mismatched

[HillBilly]

well the other 2 tubes are not doing what they should i took them to a local cb dr. he said that one was about 42% the other on was 48% so yea. The other 4 won't even light up.

[Foxhunter]

well the other 2 tubes are not doing what they should i took them to a local cb dr. he said that one was about 42% the other on was 48% so yea. The other 4 won't even light up.

Yeah I see...........Everyone I've talked to says that you can't mix new and older tube together and that it's very similar to say AA batteries if you put a bad one or two in they will pull down the others prematurely. Sounds like you need the whole set then..........

[HillBilly]

I did replace all 6 those where just the 2 that didn't blow with the power surge.

[Night Crawler]

If you replaced all the tubes and they're good check and make sure your getting the proper amount plate voltage going to the tubes under load. Also check your plate choke and bypass caps on the HV line and your coupling capacitors on the input and output.

[HillBilly]

ok ill do that and let you know something