[Amps] Rebuilding oxide cathode tubes

[John Lyles]

I believe the answer is that thoriated tungsten filaments are much easier to copy and replace, than oxide cathodes. 
Its my impression that calcium, barium, strontium oxide chemistry is somewhat proprietary among tube manufacturers, and to get long life requires 
care and very clean conditions. 

73
John
K5PRO



-----Original message-----
From: amps-request at contesting.com
Date: Tue,  6 Jul 2010 12:00:37 -0600
To: amps at contesting.com
Subject: Amps Digest, Vol 91, Issue 10

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>    1. Re: Rebuilt tubes (Carl)
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> Message: 1
> Date: Tue, 6 Jul 2010 14:42:46 -0400
> From: "Carl" <km1h at jeremy.mv.com>
> Subject: Re: [Amps] Rebuilt tubes
> To: "AMPS" <amps at contesting.com>,	"Bill Fuqua" <wlfuqu00 at uky.edu>
> Message-ID: <017c01cb1d3b$08d69e30$6501a8c0 at DAVES>
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> 	reply-type=original
> 
> I wonder why there are no cathode type tubes in that list?
> 
> Cant be done or not economically?
> 
> Since I have 3 full output 3CX1000A7's I guess Im set for awhile. One is in 
> the 2M amp
> 
> Carl
> KM1H
> 
> ----- Original Message ----- 
> From: "Bill Fuqua" <wlfuqu00 at uky.edu>
> To: "AMPS" <amps at contesting.com>
> Sent: Tuesday, July 06, 2010 2:22 PM
> Subject: [Amps] Rebuilt tubes
> 
> 
> >    Look at
> > http://www.cpii.com/docs/related/23/Tube%20Ratings%20Data%20for%20Devices%20Rebuilt%20by%20ECONCO.pdf
> >
> > It appears that ECONCO does rebuild some tubes as low as 1000 Watt plate
> > dissipation but only the rarer industrial, medical or scientific types.
> > I suspect that if they did 8877's they would be over run by ham and CBers
> > and would not be able to take care of the other customers. I had a
> > 3CW20,000 rebuilt one time for a sputtering power supply.
> >    You can always ask if they will rebuild it.
> >
> >
> > 73
> > Bill wa4lav
> >
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