It could be lots of things. But I recently had this problem and it turned
out to be the tube.
Symptoms: Pop in standby, at power up.
Visible flash, apparently coming from RF compartment
Occationally, damage to B- clamping diodes.
No carbon or other charring
Differential Diagnosis: Remove tube; apply power.
Never happened with tube removed
Alternative theories:
Parasitics
Dust, humidity, spiders and other bugs,
finger grease on the tube chimney
bent chimney clips
Cracked or damaged blocking capacitor
Actual Cure:
Replacement of the tube.
Apparently, Ameritron has seen this before and replaced the tube w/o charge
(under warranty). The tube was returned to Ameriton
for testing and 'tested good' but promptly failed when re-inserted in my
amp. Ultimately, my tube went back to Eimac.
(Yes, I know, you shouldn't have seen a flash for a tube arc, but there was
an arc. It may have been a reflection
of the step start relay arcing, or perhaps the light of the internal arc
through the ceramic)
Happy hunting
Ed
----- Original Message -----
From: "Dana Roode" <K6NR@ARRL.net>
To: "AMPS" <amps@contesting.com>
Sent: Sunday, July 04, 2004 9:25 PM
Subject: [Amps] AL-1200 Pop
> I just finished replacing the open frame relay in my old AL-1200 with the
> Ameritron relay PCB mod. Put it all back together, seemed to work fine,
> tuning on 40m. Moved to 160m, had the Amp in Standby while I set the
output
> power on the exciter. Heard a loud Pop - exciter power only.
>
> I turned the Amp off for awhile, then tried it again. It still works
fine.
> I opened it up looking for a visibly bad component, none found.
>
> Any ideas what this might have caused a Pop in Standby? Should I worry?
>
> Dana
>
> _______________________________________________
> 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
|