[NJARC] Dim eye tubes

[michael s christiansen]

Hi guys, That's why they have screen savers on computers. I've seen old
monitors with text actually burned into the CRT. And now on to something
completely different, Girl Scout Cookies will be delivered the night of
the party to those folks who purchased them at the last clinic   Thanks,
Mike Christiansen
On Wed, 6 Dec 2006 15:51:54 -0800 (PST) Jim Whartenby
<antqradio at sbcglobal.net> writes:
> Visit our web site - See http://www.njarc.org
> _______________________________________________
> Greetings Nick
> I don't know the exact cause.  The phosphor coating either wears 
> out,
> wears off or get contaminated by the electrons bombarding it.  The 
> same
> thing appears to happen to CRTs.
> 
> I visited a TV shop in Bound Brook, NJ to pick up a donation of 
> vacuum
> tubes for the club at least 8 or so years ago.  In talking with the
> owner, he mentioned that he had noticed that this problem happened 
> to a
> TV CRT he used to align video camcorders.
> 
> He had adjusted a TV so that the top portion of the CRT displayed 
> the
> sync bar and never changed the settings. It stayed this way for 
> years. 
> When he needed the set for another type of test, he readjusted the
> controls and noticed that the area that had been black, that is not
> exposed to the electron beam, showed much brighter colors then the 
> rest
> of the screen.  So it appears that the phosphors don't last forever.
> 
> Lud Sibley experimented with trying to rejuvenate eye tubes with no
> success.   He even put a tube or two in the microwave oven!  Nice
> sparks but no joy.
> Regards,
> Jim
> 
> --- Nick Senker <ns539 at earthlink.net> wrote:
> 
> > Visit our web site - See http://www.njarc.org
> > _______________________________________________
> > Why do eye tubes (eg 6U5, 6E5, etc) lose their brightness?  Is it 
> a
> > failure of the phosphor coating?  I checked one that had good
> > emmision, yet it was very dim. Nick Senker
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