The suppressor R IS critical, especially for 10M. Either use 100-120 Ohm 2W
carbons or get the Ohmite OY ceramic version at Mouser. If the amp is still
unstable use 47-51 Ohms which would be my first choice anyway as you want to
quench the parasitic from even forming. I see JI has added that concept to
his list....after Ive mentioned it for decades...and after reading it in a
50's QST. At least I dont have to be a plaigarizer... and make believe that
everything I write is a unique idea.
Carl
KM1H
----- Original Message -----
From: "Jerry Kaidor" <jerry@tr2.com>
To: <amps@contesting.com>
Sent: Saturday, June 16, 2012 2:19 AM
Subject: [Amps] Squirrely 30L-1 Redux
> Hello,
>
> Per advice received on this forum, I pulled the Chinese tubes out of
> my amp. One of them broke while I was gently wiggling it out - amazing.
> The plate cap pulled off, right along with a chunk of glass. As for the
> parasitic suppressors - both of them are cracked. So it looks like I need
> a pair of 100ohm 3-W resistors. Couldn't find any in my junk box, 240-ohm
> was the closest. So for now, I rebuilt the suppressors with the 240-ohm
> R's. I figured they're not critical - they're just there to kill the Q of
> the coil
> at the VHF frequencies. Installed my four fairly matched American 811a's.
>
> Powered it up - yeah it works - just as squirrely as before. I guess I'm
> going to go get some RG-58/U and make up a 20.5 foot cord.
>
> - Jerry Kaidor ( jerry@tr2.com )
>
>
>
>
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