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High voltage arcing in amp?

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Ima gonna guess that he didn't VNA, GDO or otherwise VERIFY the tuning of his new coil was actually RESONANT at 11 meters, instead of 6 :)

With a 6 meter tank, you can get a resonance on 11 meters..... And since it's ACTUALLY tuned to 6, you also usually get a nice peak in the wattmeter... :) Them pesky harmonics, ya know.....


BUT, to his defense, if the original coil was that screwed up, he might have saved it. I still want to know if the amp works now or not. He stated he fixed it, and it still sputters.

--Toll_Free
 
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He stated he fixed it, and it still sputters.

--Toll_Free


That's the thing, if it still sputters and arcs then he didn't fix it. He may have possibly found something wrong, but he didn't fix the amp yet. A long way back I said I didn't think the issue was the loading cap and to look at the plate blocker. I just can't imagine an amp NOT having a plate blocking capacitor in it. That thing would be a death trap.
 
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There are even commercial amps that omit Cblock...

Not in the last 50 or so YEARS, but they DID exist. Some people have put them on the opposite side of the coil as well, between L and Ctune.

--Toll_Free


Omitting a plate blocker would allow full plate voltage to reach the antenna. If a grounded antenna was used then BANG!! not to mention what could happen to the operator.

Hey Doc. you take butter on your popcorn?
 
In the early days of radio, they didn't use coax, etc. Things where MUCHO different. Collins radio invented the "collins coupler", what we call the pi net today, which pretty much puts us at the point we are.....

I agree, not having Cblock is dangerous... It also means you can't have a static drain on the output of the amp.

BUT, there are some interesting designs of feeding the plate circuit THROUGH the RF choke, which puts the feedpoint for DC at a low impedance point.... Makes it a lot easier to NOT have resonances, etc... I haven't tried it, but have been reading about it lately.


--Toll_Free
 
In the early days of radio, they didn't use coax, etc. Things where MUCHO different. Collins radio invented the "collins coupler", what we call the pi net today, which pretty much puts us at the point we are.....

I agree, not having Cblock is dangerous... It also means you can't have a static drain on the output of the amp.

BUT, there are some interesting designs of feeding the plate circuit THROUGH the RF choke, which puts the feedpoint for DC at a low impedance point.... Makes it a lot easier to NOT have resonances, etc... I haven't tried it, but have been reading about it lately.


--Toll_Free

Agreed, they generally used either a random single wire (still dangerous) or likely a balanced feeder which was fed from a link coupled balanced tuned output from the TX which would have isolated the antenna from the high voltage. It's still a scary thought however. I think I'll just continue to install plate blockers in anything I build. (y)
 
Well im done arguing with you idiots. If you read what was going on the amp lost its output and would not do anything at all... That insulator was the problem with that.. it has full output now but does like it did when I first got it and arcs in the plates. The coil is the exact same as the old one tapped in the same place. I didnt try to reinvent the coil.. Now it is the same way as when I got it, and does the same thing.
 
Well im done arguing with you idiots. If you read what was going on the amp lost its output and would not do anything at all... That insulator was the problem with that.. it has full output now but does like it did when I first got it and arcs in the plates. The coil is the exact same as the old one tapped in the same place. I didnt try to reinvent the coil.. Now it is the same way as when I got it, and does the same thing.

Yup, we are the idiots:

1. We have working equipment. We maintain it ourselves. We are stupid.
2. We didn't make the STATEMENT that we fixed our amplifier, then in the SAME paragraph STATE that it was doing the EXACT same thing as it was before.
3. We didn't shotgun the approach to your amplifier repair. Fixing the PENULTIMATE problem, the sputtering, would have been problem number one. Actually, Cblock SHOULD be problem number one, then on to the sputtering, OH SHIT, replace Cblock and all of a sudden the voltage impressed on Ctune is HALF, EYE DEE TEN TEE!!!!

Yes, screaming that the people trying to help you are idiots is SURE to get you help. Especially when your English skills leave much to be desired.... Read above, MORE THAN MYSELF QUESTIONED YOU WHEN YOU STATED YOU FIXED IT AND IT DIDN'T WORK STILL.

I'd suggest at this point taking your amplifier to someone competent in the English language, electronics, as well as reading comprehension.

I like being yelled at for trying to help you and decypher what you MEANT.

--Toll_Free
 
First off there are no idiots in this thread.

Second a sure fire way to be mistreated is calling those who want to help idiots.

Thirdly, 3022 you stated that after you fixed the problem with the insulator everything was normal. What did "normal" mean at this point? Did it mean all was well and good or did it mean that the arcing had stopped but the amp still had no or very low power output?

You see we are not idiots but perhaps you could have explained just what the hell was going on a bit better. I now assume that "normal" means normal power output but it is still arcing. If that is the case then the amp still needs work. No reasonable and knowledgeable operator would ever say "sparking persists but I dont care it works". May I suggest you chill out a bit and perhaps explain things better next time. Just exactly when the amp first developed low output was NEVER clear. I thought it had low output when you got it AND was arcing as well.
 
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Ok, well I guess I should have worded it better and things got misunderstood in 4 pages.. But it started off with just the arc then it lost the output... I fixed the output and said that was fixed but the arcing still continued, but it was back to where it was before as someone said I "ruined the box". Well thats how it was all along, nothing changed while it was in my hands... I seem to get bashed for trying to fix this stupid amp if I misword something or not use the right terms. If I do something wrong and blow it up why should anyone care, its my box? I got it working so just delete this damn topic already I'm not going to bother to respond anymore. Cya
 
Ok, well I guess I should have worded it better and things got misunderstood in 4 pages.. But it started off with just the arc then it lost the output... I fixed the output and said that was fixed but the arcing still continued, but it was back to where it was before as someone said I "ruined the box". Well thats how it was all along, nothing changed while it was in my hands... I seem to get bashed for trying to fix this stupid amp if I misword something or not use the right terms. If I do something wrong and blow it up why should anyone care, its my box? I got it working so just delete this damn topic already I'm not going to bother to respond anymore. Cya


Well there you go folks. With an attitude like that and the verbal skills to go with it I wish you all the best in your future endeavors whatever they may be. You'll need it.

The thread shall not be deleted however I no longer see the need for further comments considering the original poster considers things closed.
 
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