[Amps] Replacement of plate caps on glass tubes

[Kees - pa7two]

Hi Mike,
 
I used 2 component glue (high temperature type) after de-soldering the top cap. When the glue becomes hardened, I solder the wire back on the tube. Pretty simple. 
Vy 73, de Kees Member of an all HAM familyAmateurRadio : PA7TWO - M5TWO Locator: JO22jp Remember: QRO seperates men from QRP. HAMs be active, use it or loose it!Please visite my HAM sales webpage at  <  http://www.2dehands.nl/winkel/ham_tubes/  >



> Date: Thu, 10 Apr 2008 11:12:53 -0400> From: k2ki at starc.org> To: Amps at contesting.com> Subject: Re: [Amps] Replacement of plate caps on glass tubes> > Hi Mike,> > Yes, they can in most cases. I have successfully done it on many tubes.> > Get some Furnace cement and use that to bond the cap to the tube..> > What I do is make the hole in the top of the cap slightly larger than > the wire. Then put some lead dressing, shrink, whatever through the hole > and extend it past the bottom of the cap. Then I fill the cap with a > generous amount of Furnace cement and then slip the cap with the > dressing over the lead and slide it onto the tube. Then I carefully > remove the dressing thus exposing the clean wire. I can then solder the > lead to the tube. It works better if the dressing or whatever material > you use is a snug fit to the hole. This helps prevent the cement from > coming out with the dressing as you pull it out.> > If you need to extend the lead a bit to make it clearly out of the hole, > make sure your splice and solder the new wire to the old really well! > You don't want the thing to open up or become resistive inside the cap > from tube heating!> > Also, a little amount of flux added to the top of the cap might help > make the bonding process a little better.> > As I stated earlier, it can be done in most cases. Your mileage may vary.> > I'm sure there are many other ways to do this. and I look forward to > hearing them.> > Hope this helps...> > 73, cul...> Bob de k2ki> > K6QD wrote:> > I have some old glass tubes where the plate cap bond to the glass envelope has become loose; i.e. the cap is being held on by the soldered wire going through the glass envelope to the internal plate. The solder joint from the wire connection to the plate cap is intact and the tubes are good, but the bond to the glass has failed over time. Can the caps be unsoldered, re-bonded and re-soldered?> > Thanks for any help. > > de Mike, K6QD> > _______________________________________________> > Amps mailing list> > Amps at contesting.com> > http://lists.contesting.com/mailman/listinfo/amps> >> >> >> > > _______________________________________________> Amps mailing list> Amps at contesting.com> http://lists.contesting.com/mailman/listinfo/amps
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