[Amps] [AMPS] 3-500z "glow blue"

[Shon Edwards]

See:  http://www.jacmusic.com/html/articles/blueglow/blueglow.htm.

On Wed, Apr 7, 2010 at 3:56 PM, DAVE WHITE <mausoptik at btinternet.com> wrote:

> If I key down with my 4-1000A amp tuned up, I can see a faint blue glow
> around the glass, looking from above - but I thought that was normal
>
> Dave G0OIL
>
> --- On Wed, 7/4/10, Ryan Foster <foster.ryan at gmail.com> wrote:
>
> From: Ryan Foster <foster.ryan at gmail.com>
> Subject: Re: [Amps] [AMPS] 3-500z "glow blue"
> To: amps at contesting.com
> Date: Wednesday, 7 April, 2010, 22:05
>
> 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 at 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
> >
> >
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> > Amps at contesting.com
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> >
>
>
>
> --
> "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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-- 
Shon R. Edwards,
KO3U
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