-- 73, Les Rayburn, N1LF 121 Mayfair Park Maylene, AL 35114 EM63nf 6M VUCC #1712 AMSAT #38965 Grid Bandits #222 Southeastern VHF Society Central States VHF Society Life Member Six Club #2484 Active on 6 Meters thru 1296, 10GHz & Light On 4/23/2013 4:40 PM, Stephen E. Belter wrote: > Les, > > Here is the procedure I've used with SatPC32 and my Icom IC-821 for > Doppler correction when operating SSB. It should work with any rig that > is CAT controlled. (This is a corrected version of something I wrote a > couple of years ago in response to a similar question.) > > Your success operating SO-50 is a good proving ground. > > Here is the approach I took: > > (1) Install SatPC32, enter your station's latitude and longitude, update > the Keplarian elements, and synchronize the PC clock to a national > standard like WWV/NIST. > > (2) Get your radio and SatPC32 communicating, and verify the operation > (including Doppler correction) using an FM satellite (for example, SO-50). > > (3) Wait for a good pass of VO-52, for example 60+ degrees maximum > elevation. I suggest VO-52 because it is the newest (compared to AO-7 and > FO-29), it was more tolerant of using too much transmit power, and it had > the smallest transponder correction. Note: This was true in 2011 with > the Indian transponder. Since then the Indian transponder has failed and > VO-52 is using the Dutch transponder which is not as tolerant of high > power and isn't as frequency stable. > > (4) Open the "CAT" window. You can move the Window so that it doesn't > block access to the main SatPC32 window. Tune the radio above the center > of the satellite passband to reduce the QRM to other users. Make sure > you are in SSB mode on the radio ("CW-" on SatPC32). > > (5) Using your call and "Test 1-2-3", listen for yourself while you are > transmitting. You probably won't hear yourself at all, at least I > didn't. Using the +100 and -100 buttons in the Transmit Correction part > of the CAT window, try to find yourself. For VO-52, you should hear > yourself within +/- 1500 hertz. (I think I was about +800, but that is > from memory on the Indian transponder.) > > (6) Once you hear yourself using the +/-100 buttons, fine tune using the > +/-10 buttons. > > (7) You can improve the tuning of your uplink/downlink using CW mode > ("CW+" on SatPC32). Zero-beat the Icom's CW sidetone with your received > signal. > > (8) *Save* the result by using the "Save" button in the CAT window. When > given the choice, save the transmitter correction. > > (9) Verify that things are working by working a few VO-52 QSOs. > > (10) Repeat using FO-29 and AO-7, in that order. You may need to search > over a wider frequency range (+/-3000 hertz). > > (11) One other important change when moving from FM to SSB. Your power > output is important! Learn how to reduce your power and use the minimum > power needed to hear yourself on the satellite. If you use too much > power, you'll trash other conversations on the satellite and your > transmissions will be badly distorted! This is especially true of AO-7 > mode B; you'll be able to hear the entire satellite passband modulated by > a single CW operator running too much power. > > Good luck! > > 73, Steve N9IP > -- > > Steve Belter, [email protected] > > > On 4/23/13 3:40 PM, "Les Rayburn" [email protected] wrote: > > >> I'm very new to satellite operation but have been having a blast for the >> past couple of weeks. Using an IC-910H with attic antennas that include >> a 7 element 432 Arrow >> antenna with an SSB Electronics pre-amp mounted at the antenna. 1/2" >> hardline makes the 70' run from the attic to the shack in the garage. 2 >> Meters shows a 6 element K1FO Yagi with an SSB Electronics pre-amp and >> 1/2" hardline. >> >> Rig is controlled by SATPC32 via the CI-V interface at 9600 baud. >> >> On SO-50, I have no problems with doppler correction as you would >> suspect. With the other birds, doppler is sometimes an issue. Sometimes >> I hear stations strongly but when I call them, I don't hear my own >> uplink and the other station obviously doesn't hear me either. >> >> On other passes, the difference is not so great, and I'll hear my own >> uplink, though usually slightly off frequency. >> >> I know its possible to adjust the uplink frequency in the software, and >> I've tried it during passes without much success. The translated help >> file from German isn't much >> assistance to me so far. >> >> Can someone on the list point me towards a better explanation on the >> web, or offer suggestions on how to correct the situation? Any help is >> greatly >> appreciated! >> >> >> -- >> 73, >> >> Les Rayburn, N1LF >> 121 Mayfair Park >> Maylene, AL 35114 >> EM63nf >> >> 6M VUCC #1712 >> AMSAT #38965 >> Grid Bandits #222 >> Southeastern VHF Society >> Central States VHF Society Life Member >> Six Club #2484 >> >> Active on 6 Meters thru 1296, 10GHz & Light >> >> _______________________________________________ >> 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 >