Ref: [Amps] AL-1200 Pop

[R.Measures]

=F0  Will -- It was bandswitch arcing.  Tube arcing was due to=20
"barnacles" - which sounds like a sea story to me after having=20
autopsied tubes that supposedly arced from this malady.  .
-  Someone -

On Jul 7, 2004, at 3:56 PM, Will Matney wrote:

> Well,
>
> I'd say it was the tube arced internally first thought. I wouldn't=20
> discount parasitics causing this either. There's not too many things=20=

> that cause a loud pop in an amp. If it were an electrolytic capacitor,=20=

> you'd smelled a real sour smell coming from the amp and foil with=20
> paper would be everywhere it "once" was. If the coupling cap shorted,=20=

> it should have blown a fuse. If the tube did arc, it would have blown=20=

> a grid resistor if that amp has them. Some uses a choke and some none=20=

> at all. Let's put it this way about parasitics, MFJ the manufacturer=20=

> of your amp threatened a law suit over someone even mentioning=20
> parasitics causing tube and band switch arcing! Now that should tell=20=

> you something about it.
>
> Will
>
>
>
>
> "Subject: [Amps] AL-1200 Pop
>
> I just finished replacing the open frame relay in my old AL-1200 with=20=

> the Ameritron relay PCB mod.  Put it all back together, seemed to work=20=

> fine,tuning on 40m.  Moved to 160m, had the Amp in Standby while I set=20=

> the output power on the exciter.  Heard a loud Pop - exciter power=20
> only.I turned the Amp off for awhile, then tried it again.  It still=20=

> works fine.I opened it up looking for a visibly bad component, none=20
> found. Any ideas what this might have caused a Pop in Standby?  Should=20=

> I worry?"
>
> Dana=