>Message: 2 >Date: Fri, 11 Jun 2010 18:41:37 -0700 >From: Clint Bradford <clintbradf...@mac.com> >Subject: [amsat-bb] VO-52 - OK to Work in FM? >To: AMSAT BB <amsat-bb@amsat.org> >Message-ID: <783B57E0-1B8C-4F72-A695->acd09e6ae...@mac.com> >Content-Type: text/plain; charset=us-ascii
>The Bengal ham club posted about five years ago >instructions for working >V)-52 in FM mode. Is that still >OK to do? >"HAMSAT or VO-52 is a satellite intended for >SSB/CW operation. However as in VU land very few >of us can afford multimode VHF/UHF radios we are >accessing Hamsat on FM for which it is best to stick to >the centre frequencies (435.250 uplink and 145.900 >downlink). It is also >best to simultaneously monitor your >own signals on the downlink using a separate radio. >Hamsat requires around >100 watt ERP for solid 59 >signals. So if you are using 10 watts RF the >recommended antenna gain is around 10 db. However >Hamsat or VO-52 have been accessed on high >elevation passes using 25 watts ERP. If you want to use >omni directional antennas you can build a turnstile or an >eggbeater antenna which has a dome shaped radiation >pattern with circular polarisation. Separate 10 element >UHF and 5 element VHF crossed yagis with >circular .polarisation would give excellent results. Only >keep the transmission line loss (particularly on UHF) >minimum. Use hardline CATV cable if transmission line >is more than! > 100 feet. Otherwise if you use RG-213 keep the >feeder length to around 20 - 30 feet. I have been using a >handheld arrow yagi antenna with RG-58U cable of >around 1 meter length. Doppler compensation is needed >particularly on the UHF uplink where the signal will shift a >round 10 KHz. So for the uplink it is best to start from >435.240 MHz during AOS and end at 435.260 MHz at >LOS and on the downlink start receiving 5 KHz up at >145.905 MHz and end at 145.895 MHz. Currently the >VU transponder is on and it has a beacon (continuous >carrier) on 145.936 MHz though we have not yet r >eceived the beacon from Calcutta / Kolkata." >Clint, K6LCS It is very exciting to work VO-52 in the CW mode. She is a strong bird and hears well. I work her often on only 2 watts CW and a 12 dbi gain vertical yagi on the uplink and 10d bi for the V down link and can hear her down to about 5 degrees on most passes. LOUIS, KD5GM CW, The original digital mode _______________________________________________ Sent via amsat...@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
