[amsat-bb] Re: SATPC32 and IC-910H

Les Rayburn les at highnoonfilm.com
Wed Apr 24 09:10:30 PDT 2013


Thank your the advice on how to improve my satellite operation. Much 
appreciated, and exactly what I was hoping for when I posted the questions
to the AMSAT BB. Tried it last night on a pass with mixed results.  But 
I think I understand the principle now.

I'll also look for you on the birds---I need your grid! :-)


Les Rayburn, N1LF
121 Mayfair Park
Maylene, AL 35114

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, seb at wintek.com
> On 4/23/13 3:40 PM, "Les Rayburn" <les at highnoonfilm.com> 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
>> _______________________________________________
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