He meant they didn't look "gassy" (blue ionization inside the envelope).
Actually, I've been PMing with Jay and the problem was the T-R relay.
"One of the usual suspects."
WB2WIK/6
-----Original Message-----
From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com]
On Behalf Of Ryan Foster
Sent: Wednesday, April 07, 2010 2:05 PM
To: amps@contesting.com
Subject: Re: [Amps] [AMPS] 3-500z "glow blue"
I changed the subject so I don't hijack the thread.
What does "Tubes do not glow blue" mean? What don't I know about blue
glowing tungsten filaments? I've never seen this and never heard of
it.
--Ryan w8cya
On Wed, Apr 7, 2010 at 11:43 AM, JayKay <pcb4u@verizon.net> wrote:
> HI all
>
> Need some help. I have a friends SB220 that does not accept RF drive.
Following info
>
> 1) Plate voltage good at tubes
> 2) Looks like 30 ohm parasitic resistors/cap (aftermarket) are good,
both tubes
> 3) Relay closes...TUNE position plate idles at 100ma
> 4) When relay closed I do have a DC path from RF input via relay to
tube just prior to .01uf coupling capacitor.
> 5) In standby RF path good from INPUT to OUTPUT
> 6) Tubes do not glow blue
> 7) The tubes appear OK (physically), passed the "shame next to ear"
test
> 8) No grid current
> 9) Driving rig (TS950) shows INFINITE SWR which (to me) indicates an
open or short (RF wise) in input.
> 10) 5 volt zener OK when relay energized
>
> I am thinking it could be the .01uf coupler to the filaments
>
> Thoughts?
>
> Jay
> W2IJ
>
>
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
--
"If someone has a gun and is trying to kill you, it would be
reasonable to shoot back with your own gun." -- The Dalai Lama, May
15, 2001
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