Eddy, I don't think aluminum foil makes good gasketing material for two reasons. At least in this country, the shiny side of the foil is coated with Mylar which is nonconducting. In addition, aluminum oxide is an insulator as well.
73, Bob AD3K -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Eddy Swynar Sent: Monday, July 18, 2011 12:27 PM To: Steve Wedge Cc: [email protected] Subject: Re: [Drakelist] R-4A PTO, Act III Hi Steve, The frequency of my T-4X PTO jumps upward almost exactly 100-KHz with the cover removed... I've tried several different "tricks" in futile efforts at trying to tame mine, including (A) unplugging the cooling fan that I added to allow everything inside to "heat soak" properly in the confines of my cool basement (no change), and, (B) "gasketing" the seam at the base of the PTO shield can with aluminum foil to better shield its contents, and to negate any effect that expansion/contraction of the shield might have upon the frequency (again, no effect). I have yet to re-enter the inner sanctum of my PTO here (far too busy with other stuff), but when I do I plan to completely swab everything down inside it that moves with isopropyl rubbing alcohol & Q-tips. The frequency flutter is so very vexing for me that I'm afraid it's fast-removing the gleam in my eye that I've heretofore reserved for Drake gear---indeed, I'm almost ashamed to admit that I'm coming to more & more appreciate the sheer joy & pleasure of the reliability & quality of signal that my old Icom 751A affords me in my portable work, as compared to the on-going grief given me thus far by the Drake Twins. That's sacrilege, I know, admitting such on a Drake Reflector, but it is, alas, a sad reality & fact... ~73~ de Eddy VE3CUI - VE3XZ **************************************************************************** ******************************************* On 2011-07-18, at 12:13 PM, Steve Wedge wrote: > Logging on from work: > > Garey, I thought about that last night and, as luck would have it, I had an extra good 6HS6, which I swapped. There was no change. > > The PTO seems to be a bit better with the cover removed, not the entire unit. Of course the frequency of the PTO changes considerably with the cover off. It's got me scratching my head, as there should really be no significant heat being generated in there... > > W1ES > > Date: Mon, 18 Jul 2011 10:11:15 -0400 > From: Garey Barrell <[email protected]> > To: [email protected] > Subject: Re: [Drakelist] R-4A PTO, Act III > Message-ID: <[email protected]> > Content-Type: text/plain; charset=windows-1252; format=flowed > > Steve - > > This has been 'one of those' problems! Just a quick question.... I've forgotten if you said the PTO > was stable outside the radio? IF so have you subbed the PreMixer tube? Possible load change on the > PTO due to a tube anomaly? > > 73, Garey - K4OAH > Glen Allen, VA > > > > _______________________________________________ > Drakelist mailing list > [email protected] > http://mailman.zerobeat.net/mailman/listinfo/drakelist _______________________________________________ Drakelist mailing list [email protected] http://mailman.zerobeat.net/mailman/listinfo/drakelist _______________________________________________ Drakelist mailing list [email protected] http://mailman.zerobeat.net/mailman/listinfo/drakelist
