Ditto! Great post Greg!
----- Original Message ----- From: "Tom Hammond" <[EMAIL PROTECTED]> To: "G. Beat" <[EMAIL PROTECTED]>; <[email protected]> Sent: Tuesday, December 14, 2004 8:44 AM Subject: RE: [Elecraft] OT: Repairing Astron RS-20 > Greg: > > Wish I'd had these (first two) references back YEARS ago when I was first > learning about linear supplies.. would have made things a LOT easier. > > These should be MUST HAVE links for all hams! > > 73, > > Tom N0SS > > > At 03:15 AM 12/14/04, you wrote: > >Harold, > > > >A couple of suggestions in repairing your Astron. > >You MUST discharge the large filter capacitor before removing or replacing > >the LM723 regulator IC (this is the part you will likely have to replace). > > > >The RS-20 uses 2N3055 pass transistors, but you can also use 2N3771 (which > >is what Astron has been using on newer units). Test the pass transistors, > >IF you are replacing the LM723 (testing with a VOM is covered in the KBT > >web site - below) > > > >Excellent reference web site for understanding, troubleshooting and > >repairing linear power supplies > >http://www.kbt-dc-supplies.com/index.php > > > >Dave Metz, WA0AUQ's article "What Inside Your Astron?" > >http://www.seits.org/features/pwrsup.htm > > > >This is a very easy repair, and it one of the Amateur technical basics > >(audio, power, antennas) that I teach new amateurs. > > > >Astron schematic diagrams > >http://www.repeater-builder.com/rbtip/astron-index.html > > > >Greg > >w9gb > > > > > Message: 11 > > > Date: Mon, 13 Dec 2004 09:47:45 -0600 > > > From: "James" N5TOG > > > Subject: [Elecraft] OT: Astron RS 20 schematic > > > > > > Would some one have a schematic for an Astron RS 20 power supply they > > could > > > email me or know were i can find it. > > > Sincerely Harold N5TOG K2 1587 > >_______________________________________________ > >Elecraft mailing list > >Post to: [email protected] > >You must be a subscriber to post to the list. > >Subscriber Info (Addr. Change, sub, unsub etc.): > >http://mailman.qth.net/mailman/listinfo/elecraft > > > >Help: http://mailman.qth.net/subscribers.htm > >Elecraft web page: http://www.elecraft.com > > _______________________________________________ > Elecraft mailing list > Post to: [email protected] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
