Hello Tom, the automatic Doppler correction works flawlessly. However, the program does not update the radio frequencies every second (that is not neccessary and would take a lot of system time), but only when the Doppler shift of the higher one of both frequencies has changed by more than the "interval". In menu "CAT" the interval can be set separately for FM and SSB sats (default: 100 Hz for SSB, 600 Hz for FM sats). So, if the Doppler shift changes rather slowly, it may look as if the automatic Doppler correction wouldn't t work. Decrease the intervals in menu CAT and watch the changes of the Doppler shift. Whenever the Doppler shift of the higher band changed by more than the interval the program will update both radio frequencies.
73s, Erich, DK1TB
----- Original Message ----- From: "Tom Schuessler" tjschuessler@verizon.net To: amsat-bb@amsat.org Sent: Sunday, April 10, 2011 6:38 AM Subject: [amsat-bb] SATPC32 and FT847
Hi all,
In an attempt to dabble my toes in the linear transponder pool, I asked a FT847 owner friend to bring his rig over to try and understand the mechanics of making it all work with the computer interfaced. Got SatPC32 to communicate at 9600, 8, none, 1, none, with the radio and the radio responded to changes I made on the program like using keystrokes to modify the frequency of uplink or downlink. Problem is that although the program was tracking Doppler correctly, the radio was not tracking at all. With the multiple lines of possibilities on the Doppler.sqf file as is the case for AO-51, I can go to the CAT dialog and change the mode frequencies just fine, the radio goes to the new frequencies and even reflects the current state of the Doppler shifted frequencies but from there, no Doppler corrections occur.
Now I remember reading the "Manual" that "CAT Delay" for the FT897 needed to be set to 20. Cat Delay is in the "Radio Setup" dialog is defaulted to 70. I realize this now after the fact with radio not in my presence. Is this the reason that the above mentioned problem could be occurring?
I hope to make another go at this in a few weekends in the hope of getting ready for Field Day. Thanks for the help of the list.
Tom Schuessler 2713 Lake Gardens Drive Irving, Texas 75060 972-986-7456 214-403-1464 (Cell) n5hyp@arrl.net
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