Re Exploding cap. ?? TR4 AC4 Danien I would guess that is what it is. I has a massive crack from putting a tiny 50uF 20V the wrong way round.
I might have a similar experience as you have had some time in the future when I get round to powering up my L4B which has never been switched on. The guy from Drake told me to do as you did, very slowly power up the caps on a variac. Incidentally, I had also been warned to really bake in the filaments for a few days before putting the HT, otherwise there would be arcing, though this precautionary not be relevant to your valves/tubes. Like you, I have returned to amateur radio after, in my case 43 years. I have a ton of Drake stuff, since I loved the Drake 2B in 1964, but only have had the time to put up a receiving aerial. May have to wait till I retire/ Nigel Patterson G3YDT On Fri, Aug 24, 2012 at 5:00 PM, <[email protected]> wrote: > Send Drakelist mailing list submissions to > [email protected] > > To subscribe or unsubscribe via the World Wide Web, visit > http://mailman.zerobeat.net/mailman/listinfo/drakelist > or, via email, send a message with subject or body 'help' to > [email protected] > > You can reach the person managing the list at > [email protected] > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Drakelist digest..." > > > Today's Topics: > > 1. Exploding cap' ??? (Damien Mannix) > 2. Re: Exploding cap' ??? (Ed Tanton) > 3. Re: Exploding cap' ??? (Charles Ring) > 4. Re: Exploding cap' ??? (Ed Tanton) > 5. FOR SALE: Drake T4XC Transmitter and AC4 Power Supply > (William Mills) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Thu, 23 Aug 2012 16:24:05 +0000 > From: Damien Mannix <[email protected]> > To: <[email protected]> > Subject: [Drakelist] Exploding cap' ??? > Message-ID: <[email protected]> > Content-Type: text/plain; charset="iso-8859-1" > > > > > > Hi all, Bought an immaculate looking TR4 which has been out of use a long > time. Also bought an AC4 which claims to have had the original EHT caps > and diodes replaced. Powered them up with 20 vac for four hours, then up in > 20 v steps at four hours per step, listening and sniffing for any problems. > Reached 220 vac an hour ago. AC4 slightly warm and centre of TR4 top a > bit warmer. Then there was one hell of a crack! Sounded like a gunshot > and frightened me to death! Swiched off immediately of course. No smell > that I can detect. Is that what an exploding capacitor sounds like? Any > advice on where to start looking? The TR4 or the AC4? Sad day for me. > Trying to return to the hobby after over 30 years. Been too busy making a > living and bringing up a family. Regards, DamienG3XER > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://mailman.zerobeat.net/pipermail/drakelist/attachments/20120823/4db821dc/attachment-0001.html > > > > ------------------------------ > > Message: 2 > Date: Thu, 23 Aug 2012 13:26:52 -0400 > From: "Ed Tanton" <[email protected]> > To: "'Damien Mannix'" <[email protected]>, > <[email protected]> > Subject: Re: [Drakelist] Exploding cap' ??? > Message-ID: <[email protected]> > Content-Type: text/plain; charset="us-ascii" > > Is it possible power supply was set for 110V not 220V? I do not believe > it's > the TR4-although of course it could be. If it was, I should think you would > have lost a diode(s) or Heaven-forbid: the transformer. It could have been > a > faulty diode that caused it-hence, after making sure about the input > voltage > selector (and if it's correct, I'd check its wiring) I'd check all the > diodes. > > > > Finally, it's always possible it was just the capacitor's time having come. > If you've made sure about the voltage setting, then replace the cap, do the > same start-up routine, and then the SAME cap goes, then yeah, it's > obviously > not the caps, but something else going on. > > > > Before you walk-away for the run-time test, I'd check all the voltages just > to be sure they're right. That way, if it does go again (or some other cap) > you'll know at least it LOOKED right prior to catastrophe. > > > > Ed Tanton > > website: <http://www.n4xy.com/> http://www.n4xy.com > > All emails <IN> & <OUT> checked by > Norton AntiVirus with AutoProtect > > -------------------------------------------------- > Wag more / Bark less > -------------------------------------------------- > > > > From: [email protected] [mailto: > [email protected]] > On Behalf Of Damien Mannix > Sent: Thursday, August 23, 2012 12:24 PM > To: [email protected] > Subject: [Drakelist] Exploding cap' ??? > > > > Hi all, > > Bought an immaculate looking TR4 which has been out of use a long time. > Also bought an AC4 which claims to have had the original EHT caps and > diodes > replaced. > > Powered them up with 20 vac for four hours, then up in 20 v steps at four > hours per step, listening and sniffing for any problems. Reached 220 vac > an > hour ago. AC4 slightly warm and centre of TR4 top a bit warmer. Then > there > was one hell of a crack! Sounded like a gunshot and frightened me to > death! > Swiched off immediately of course. No smell that I can detect. > > Is that what an exploding capacitor sounds like? Any advice on where to > start looking? The TR4 or the AC4? > > Sad day for me. Trying to return to the hobby after over 30 years. Been > too busy making a living and bringing up a family. > > Regards, > > Damien > G3XER > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://mailman.zerobeat.net/pipermail/drakelist/attachments/20120823/b8d3cdd6/attachment-0001.html > > > > ------------------------------ > > Message: 3 > Date: Thu, 23 Aug 2012 15:55:03 -0400 > From: Charles Ring <[email protected]> > To: Damien Mannix <[email protected]> > Cc: [email protected] > Subject: Re: [Drakelist] Exploding cap' ??? > Message-ID: <[email protected]> > Content-Type: text/plain; charset="iso-8859-1"; Format="flowed" > > > On 8/23/2012 1224, Damien Mannix wrote: > > Hi all, > > > > Bought an immaculate looking TR4 which has been out of use a long > > time. Also bought an AC4 which claims to have had the original EHT > > caps and diodes replaced. > > > > Powered them up with 20 vac for four hours, then up in 20 v steps at > > four hours per step, listening and sniffing for any problems. Reached > > 220 vac an hour ago. AC4 slightly warm and centre of TR4 top a bit > > warmer. Then there was one hell of a crack! Sounded like a gunshot > > and frightened me to death! Swiched off immediately of course. No > > smell that I can detect. > > > > Is that what an exploding capacitor sounds like? Any advice on where > > to start looking? The TR4 or the AC4? > > > > Sad day for me. Trying to return to the hobby after over 30 years. > > Been too busy making a living and bringing up a family. > > > > Regards, > > > > Damien > > G3XER > > > > I had this happen to an R-4B probably 25 years ago. A medium sized lytic > went off like a bomb. Many tiny fragments to extract from under the > chassis but upon replacing the cap, all was fine. Very startling. > > -- > *Charles Ring W3NU* > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://mailman.zerobeat.net/pipermail/drakelist/attachments/20120823/67d6d0de/attachment-0001.html > > > > ------------------------------ > > Message: 4 > Date: Thu, 23 Aug 2012 16:06:42 -0400 > From: "Ed Tanton" <[email protected]> > To: "'Charles Ring'" <[email protected]>, "'Damien Mannix'" > <[email protected]> > Cc: [email protected] > Subject: Re: [Drakelist] Exploding cap' ??? > Message-ID: <[email protected]> > Content-Type: text/plain; charset="us-ascii" > > I forgot to mention I was present when one within my Drake L7 went. Filled > the basement with little tiny things that looked a lot like tiny black > butterflies fluttering to the floor. I don't remember if diodes went or > not. > But it did repair easily enough. > > > > Ed Tanton > > website: <http://www.n4xy.com/> http://www.n4xy.com > > All emails <IN> & <OUT> checked by > Norton AntiVirus with AutoProtect > > -------------------------------------------------- > Wag more / Bark less > -------------------------------------------------- > > > > ///snip > > > I had this happen to an R-4B probably 25 years ago. A medium sized lytic > went off like a bomb. Many tiny fragments to extract from under the chassis > but upon replacing the cap, all was fine. Very startling. > > -- > Charles Ring W3NU > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://mailman.zerobeat.net/pipermail/drakelist/attachments/20120823/e3ada980/attachment-0001.html > > > > ------------------------------ > > Message: 5 > Date: Thu, 23 Aug 2012 16:57:57 -0400 > From: "William Mills" <[email protected]> > To: <[email protected]> > Subject: [Drakelist] FOR SALE: Drake T4XC Transmitter and AC4 Power > Supply > Message-ID: <F2F0E2EEB3FA42A38617AED2B8FD8E15@D3DT6RD1> > Content-Type: text/plain; charset="iso-8859-1" > > > Excellent condition Drake T4XC transmitter and AC4 power supply for > sale. Also, AC4 power supply capacitor upgrade kit to be installed. If > interested, send me an e-mail or call (478-452-2957) and make a reasonable > offer on the package or single items. > > 73, > Bill Mills > KC4AA > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://mailman.zerobeat.net/pipermail/drakelist/attachments/20120823/2bde3683/attachment-0001.html > > > > ------------------------------ > > _______________________________________________ > Drakelist mailing list > [email protected] > http://mailman.zerobeat.net/mailman/listinfo/drakelist > > > End of Drakelist Digest, Vol 50, Issue 19 > ***************************************** >
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