One more update: the relays can be purchased here! http://radiodan.com/ted_stuff/tohtsu.htm
73, Mark N8MH At 09:33 PM 6/1/2011 -0400, Mark L. Hammond wrote: >Hello Domenico I8CVS, > >I did take pictures while I had the cover off :) You can see and download >them here: > >https://sites.google.com/site/marklhammond/hamradio > >Indeed, they are labeled "COAXIAL RELAYS" as you suspected. > >You can also see the "little white button" on the relays that I mentioned >previously. > >73! > >Mark N8MH > >At 02:42 AM 6/2/2011 +0200, i8cvs wrote: >>Hi Mark, N8MH and All guys on the list. >> >>I am very happy that you solved the problem on your preamplifier and since >>you took the cover off I would like to know if the relays are or not >>"COAXIAL RELAYS" or just non constant impedance relays for AC or DC >>applications. >> >>Can you take a picture on the inside of preamplifier and send it to me by >>email ? >> >>I remember that the owner of Landwehr was a 432 MHz EME'r in the early 1973 >>and I worked him off the moon but actually I don't remember his call letter >>from Sweden. >> >>I believe that he dismitted the production of the above preamplifiers many >>years ago. >> >>Tanks >> >>73" de >> >>i8CVS Domenico >> >>----- Original Message ----- >>From: "Mark L. Hammond" <[email protected]> >>To: "Amsat - BBs" <[email protected]> >>Cc: "i8cvs" <[email protected]>; "Vince Fiscus, KB7ADL" >><[email protected]>; "K5OE" <[email protected]> >>Sent: Thursday, June 02, 2011 1:44 AM >>Subject: Fixed! Re: Landwehr 70cm preamp device question? >> >> >>> Hello All, >>> >>> You gotta love a happy ending ;) >>> >>> Thanks to I8CVS, Domenico; Vince, KB7ADL; and Jerry, K5OE for the advice >>and coaching with troubleshooting my Landwehr 70 cm preamp. >>> >>> I took the cover off and applied 12V, and the two relays closed----or did >>they?!? >>> >>> One side looked good, while the other side didn't quite push the "little >>white button" enough to make the contacts meet. It was stuck--just a gentle >>push with the finger, and I could tell it had become "unstuck." Inserted >>back in line, and bingo! It's working just fine. >>> >>> I have resisted my urges to spray something down in there...figure I can >>unstick it the same way another time, should it happen. Looks like the >>preamp was made in 1990, based on the dates of the relays. >>> >>> What I was seeing seemed like it might be a relay issue on one side (could >>hear a rise in noise, so the relay at the output side (rig) was working--but >>the relay on the input side (antenna) wasn't. So, when powered, the input >>relay didn't switch over correctly--what I was seeing now makes sense! >>> >>> Anyhow, it wasn't the GaAsFET after all. >>> >>> Thanks again for the help, guys. >>> >>> 73, >>> >>> Mark N8MH >>> >>> >>> >>----- Original Message ----- >>> >>From: "Mark L. Hammond" <[email protected]> >>> >>To: "Amsat - BBs" <[email protected]> >>> >>Sent: Tuesday, May 31, 2011 8:00 PM >>> >>Subject: [amsat-bb] Landwehr 70cm preamp device question? >>> >> >>> >>> Hello All, >>> >>> >>> >>> I have an old Landwehr preamp that apparently uses the MGF1402 device >>> >>> (does that sound right?). It's not working so I presume it's the >>> >>> GaAsFET. >>> >>> >>> >>> Can the MGF1302 be substituted for the original MGF1402? Or can >>> >>> anybody recommend another device for the 70 cm Landwehr? >>> >>> >>> >>> I need to do something... >>> >>> >>> >>> Thanks in advance! >>> >>> >>> >>> -- >>> >>> Mark L. Hammond [N8MH] >>> > >_______________________________________________ >Sent via [email protected]. Opinions expressed are those of the author. >Not an AMSAT-NA member? Join now to support the amateur satellite program! >Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb _______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
