Steve-
How about putting a high pot tester on the entire shebang?
We found a random arc that was blowing past a standoff insulator
to the chassis once that way.
Tom
K0SN
On Sun, Feb 15, 2026 at 2:36 PM Steve Bookout, NR4M <steve@nr4m.com> wrote:
> Good suggestion, but don’t think so. Solid AC line and nothing dimmed.
> Computer would have reset.
> Didn’t see any type of glitch from the amp meters as I was facing the amp.
> The other fellow, Gary, mentioned tube arcing. Surely, could be that. I
> can pull the tube and hi-pot it. Unless, some really marginal voltages
> before a fault, that might not tell me much.
> I’ve got several tubes and I could swap one out, but does not PROVE
> anything. With this tube, I may never see it happen again.
> Of course, I’d love to never see this become a REAL problem. It would
> really define the problem, but may not be good for the equipment.
> I had a Millen HV connector arc over 20 years ago. The problem was easy
> to find, but it took months to find all the damage it caused.
> I appreciate you and Gary sharing your thoughts.
>
> Steve NR4M
> Sent from my iPhone
>
> > On Feb 15, 2026, at 4:08 PM, Tim Duffy <k3lr@k3lr.com> wrote:
> >
> > AC mains "brown out"?
> >
> > 73
> > K3LR
> >
> > -----Original Message-----
> > From: Amps [mailto:amps-bounces@contesting.com] On Behalf Of Gary
> Schafer
> > Sent: Sunday, February 15, 2026 3:53 PM
> > To: Steve Bookout
> > Cc: amps@contesting.com
> > Subject: Re: [Amps] AL-1500 'thump'
> >
> > Sounds like the tube arcing.
> >
> > 73
> > Gary K4FMX
> > Gary Schafer
> >
> >
> >> On Feb 15, 2026, at 12:40 PM, Steve Bookout <steve@nr4m.com> wrote:
> >>
> >> Hello all,
> >>
> >> Had a friend using the station this weekend, and while sitting there
> with him, while operating on 40 meters, we both heard a 'thump' or 'thungg'
> from the amp while transmitting. Happened two or three times or a period
> of a few hours.
> >>
> >> Reminded me of the sound the current surge makes when you first turn
> the HV on in an amp.
> >>
> >> Puzzling to me cuz if that was it, why and why now? And, no other
> follow up issues. I don't think a PS filter cap would 'sorta, kinda'
> short, then not and be OK. It would only be a small part of a larger
> 'event'. (Been there; done that and still remember the pucker factor.)
> >>
> >> Amp was being operated in a typical fashion, with resonant load, 25
> watts of drive, ~ 40 ma grid current, +/- 1200 watts RTTY.
> >>
> >> Dealt with many amps before, but have not heard anything like this in
> the past. 'If' it had a soft start to deal with initial current surge, I
> might think there was a problem there, but there isn't one.
> >>
> >> Ideas?
> >>
> >> 73 Steve NR4M
> >>
> >>
> >>
> >> _______________________________________________
> >> Amps mailing list
> >> Amps@contesting.com
> >> http://lists.contesting.com/mailman/listinfo/amps
> >
> >
> > _______________________________________________
> > Amps mailing list
> > Amps@contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
> >
>
>
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|