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
