Jim and fellow Drake enthusiasts,
That is an interesting point Jim brought up. This is the reason why I used Teflon tubing on the brass rods, sometimes with heatshrink as well, and used RTV or hot glue to hold the caps in place so there is air spacing between adjacent caps. The originals were of slightly larger diameter than the computer caps so the air gap works to advantage. However, there is only about 325 vdc across any two terminals/points on the capacitor so the insulation on the can itself might even be adequate. But extra doesn't hurt either. 73, Evan, K9SQG -----Original Message----- From: Jim Shorney <jshor...@inebraska.com> To: Drakelist <Drakelist@zerobeat.net>; John King <k5...@yahoo.com> Sent: Fri, Jan 17, 2014 11:57 pm Subject: Re: [Drakelist] L4B power supply I've never done it. But I may need to in the near future, My L-7PS is still running on original caps. Clean brass with 63/37 Kester solder and maybe a little extra liquid rosin flux should work fine. The only thing that may be of concern with this method is the length of brass rod running along the side of the can. As some of us have found out, the "isolated" can on those capacitors can develop a voltage potential. Not necessarily a problem, as it would be through a high impedance leakage path, but I think I would prefer a little more insulation between that rod and the can. OTOH, Evan and Ron are both pretty sharp techies, and I'm sure they would have revised the article if there was a problem. 73 -Jim NU0C On Fri, 17 Jan 2014 20:23:40 -0800 (PST), John King wrote: >Thanks Jim. That is a wonderful technical article. I will certainly follow it. I have never soldered brass rod. Is it difficult? Any special solder required? I really appreciate your assistance. 73, John, K5PGW > > > > > >On Friday, January 17, 2014 9:50 PM, Jim Shorney <jshor...@inebraska.com> wrote: > > >This may be the droid you are looking for: > >http://www.wb4hfn.com/DRAKE/DrakeArticles/TechTips/ElectrolyticRelacements.htm > >73 > >-Jim >NU0C > > >On Fri, 17 Jan 2014 18:06:14 -0800 (PST), John King wrote: > >>I have the power supply out of covers and the caps and mounts loose. Two of the eight cap previously changed. At least one 50K 50 watt bleeder appears open. I plan to replace all caps, diodes and resistors. Not interested in changing layout of supply or redesigning it physically. >> >>Is there a replacement board other than the one from Heath shop? I have eight new 470 MFD @ 450 VDC caps with both terminals + and - on the same end. New caps 105 degree rated about 1/2 the height of the original caps. >> >>Anyone have suggestions for a rebuild? Please reply directly. Thank and 73, John, K5PGW -- "I aim to misbehave." - Captain Malcolm Reynolds, "Serenity" _______________________________________________ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
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