Hi John, Thanks for writing that up. With a simple diagram, it would make an excellent Journal article (hint hint).
I should also point out that High Sierra Microwave makes a UHF to HF converter, the 435M7 near the bottom of the page at http://www.hsmicrowave.com/page12.html . It outputs to 10 to 13 Mhz, but that should be no different than 10m for newer rigs like the TS-2000. The noise figure looks really good, and I expect the quality to be much better than the Hamtronics. The owner is a big AMSAT supporter too. 73, Drew KO4MA -----Original Message----- >From: John Papay <j...@papays.com> >Sent: Nov 30, 2011 10:49 AM >To: amsat-bb@amsat.org >Subject: [amsat-bb] TS2000 ~436.798 MHz Birdie Solution > >As many of you know, my satellite radio is a TS2000X. >If you have visited my satellite webpage, you have seen >many recordings of AO-27 and SO50 from AOS to LOS. Most >of these recordings were made when I was not sitting in >front of the radio. > >At first I used a uhf mobile to hear AO-27 and SO-50. The >problem was that those radios were not computer controlled >so you had to tune for the doppler. That worked fine when >I was in the shack, but it didn't work when I was away. The >obvious solution was another radio that didn't have the birdie >problem, or a simple UHF to 10M downconverter which wouldn't >have the birdie problem. Back in the day, UHF and VHF down- >converters were very popular because we didn't have a lot of >DC to Light radios out there. Now these converters are sitting >in junk boxes and are long forgotten by their owners. > >One of the more popular manufacturers of these inexpensive >downconverters was Hamtronics. They made all kinds of stuff >for repeaters etc. At first their products were not that great, >but they evolved into some better designs including their >UHF to 10m downconverters. Unfortunately most downconverter >manufacturers stopped making them when the devices they were using >became obsolete and unavailable. The use of current production >devices required a redesign of their PC boards and since the demand >was no longer there, these products were abandoned. > >I was fortunate to find a Hamtronics converter on a qrz.com posting >from several years back. It never sold back then and the owner still >had it. I purchased it and ran some tests on it against the receiver >in the TS2000. It turned out that the downconverter had a slightly >better sensitivity than the TS2000! > >The big concern when using a converter or preamp is the fear of >transmitting into it and smoking the front end. But the TS2000 >has an auxiliary antenna jack which is receive only and perfect for >a downconverter output on HF. As Drew mentioned, SatPC32 can >compensate for a downconverter and tune the TS2000 for doppler >in the 10m band. This allowed me to track AO-27 AO-51 and SO-50 >unattended and make all those recordings without any human >intervention. > >A coaxial transfer relay was inserted into the uhf antenna line so >that when the converter was in use, the UHF antenna was switched >to the downconverter input (which outputs to the aux antenna jack >on the TS2000) and the UHF antenna jack on the TS2000 is switched >to a dummy load. So if you transmit on UHF, power goes into the >dummy load and all equipment is safe. When I want to transmit on >UHF (VO-52 and AO-7 mode B), the coax relay switches the UHF antenna >back to the UHF antenna port on the TS2000. The downconverter is out >of the antenna circuit at this point. I did not use the downconverter >when operating on FO-29 so the aux antenna jack had to be switched to >normal in the tS2000, menu #18 (FO-29 is a linear bird that outputs on >UHF, currently not working). > >Every owner of a TS2000 that operates satellites needs a UHF to 10M >downconverter. Hamtronics is making a VHF to 10M downconverter now. >If everyone emailed them to encourage them to make a UHF model, they >might just do it. The only other solution is to make one yourself, >or find a used downconverter or transverter that is gathering dust on >someone's shelf. I now have an IC910H and am doing comparisons against >the TS2000. My first impression it that I prefer the TS2000 but that >might be because I'm so familiar with it. I use another TS2000 in the >mobile sat truck but don't have a downconverter for it. I simply use >a uhf mobile for receive on AO-27 and SO-50 since I'm in front of the >radio and don't run it unattended. I have a coax switch to switch >the UHF antenna from the TS2000 to the UHF mobile. > >Now that AO-51 is silent, all of the FM operation is on SO-50 and AO-27. >If you have a TS2000, you'll want to investigate the use of a downconverter. > >73, >John K8YSE > > >_______________________________________________ >Sent via AMSAT-BB@amsat.org. 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 AMSAT-BB@amsat.org. 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
