Gary Blau
W3AM - Phoenix, AZ
w3am@juno.com
http://www.qsl.net/w3am/
On Fri, 5 Dec 97 08:38:28 -0800 Rich Measures <measures@vc.net> writes:
>
>An inexpensive source of tube testing is commercial broadcast tube
>rebuilders. However, a second opinion is not a bad idea. . I know of
>a
>number of instances where customers were told that a tube needed to be
>
>rebuilt - but a second test (from a different source) indicated that
>emission was normal.
>- Here's how the scam works: The customer is told something like
>this: "Your tube is a dud, sir, however we can recarburize the
>filament for you and restore full emission." If the customer declines
>to
>have the filament recarburized, he is told: "We can either return the
>
>dud to you, or purchase the core, and send you a cheque." . . Don't
>
>fall for it. A core is worth much more to someone who needs a core --
>
>and the second test may indicate good news.
>- If you need a padded factory-style shipping container, they are
>available at reasonable cost from tube rebuilders.
>- To avoid mixups, record the serial number of tubes that you send to
>a
>rebuilder for testing.
>Rich...
>
>R. L. Measures, 805-386-3734, AG6K
Right on. Always track your serial numbers. And insist that the
rebuilder use YOUR dud!
FWIW, I have used many rebuilds over the years from Econco and Freeland
Products and have had very good luck. I've never had a bad business
experience with either. Granted, this is primarily with higher power
tetrodes for VHF & FM broadcasting. For whatever reason, it seems that
some new tubes are good, long-lifers and some lose emission much earlier.
The rebuilds of the long-lifers always seem to also reincarnate well.
The short-timers have been very unpredictable. I've always put this off
to some flaw in original manufacture. Maybe I'm all wet. I'm very
interested to see how Eimac's new remanufacturing service does. However,
I must say that I've had very variable results just buying new tubes from
them in the past few years. I don't think I'm alone there. The rule of
thumb with broadcasters is that if you find a good new tube with a long
emissive life, hold onto it dearly and have it rebuilt as many times as
you can!
Gary W3AM
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