Hi John,
Here is a quote from Wouter Jan Ubbels PE4WJ (Delfi Team):
.......................
" Tuning can sometimes be difficult, in the presence of Doppler shift, fading due to polarization changes, frequency offset due to temperature of the spacecraft oscillators and there is the possibility that the Costas Loop indicates a false sync because of lock on one of the signal's sidebands. If possible, you can use a waterfall display in software like MixW running parallel to RASCAL which will give you an indication of the center frequency.
During transmission of AX.25 flags, the actual carrier frequency is the highest peak in the spectrum, with a couple of sidebands exactly 150Hz apart, looks like a comb. Now, using the waterfall display, tune such that this highest peak corresponds to 1600Hz +/-100Hz, in order to achieve sync. " ...........................
...As you can see the last part is very important. The highest peak is the one that you will center around 1600Hz. You do that by tuning your radio. Once you have it centered the Doppler control will keep it there (more or less) and only minor adjustments are necessary afterwards (depend also which Keppler data you are using).
I have attached pictures of my screen from last night and two days ago. You can see it on "Spectran". I have that program running on top of Rascal. Try it, it is fun and don't get frustrated.
73, Stefan VE4NSA
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of john heath Sent: May-04-08 3:11 AM To: Jeroen Vreeken Cc: amsat Subject: [amsat-bb] Re: FT 847 and Doppler for Delfi
Hi Joroen,
Try a hard reset, the software in the 817 may have become corrupted.
Try running with the software COMMANDER I find it works realy well, and it gives you some more features on the 817. It was written by the authjor of Ham Radio Deluxe.
Good luck.
73 John G7HIA
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