Hi,
Having fun here with Delfi and RASCAL. Keeping on tune and in sync is quite tricky though.
Using computer control via the CAT port the Yaesu FT847 seems to limited to 10Hz steps. When manual tuning the available steps are Normal 0.1, 1, 10 Hz. Default 1Hz ( page 23 in the manual)
Does anyone on the bb know if the CAT frequency step can be modified, perhaps by a hidden menu or similar.
BTW this 10Hz limitation seems to apply to the FT817 as well.
A posting from YAESU on this subject would I am sure be of interest as there are a lot of FT847 users on this bb.
73 John G7HIA
PS/ thanks to the Delfi team, and especially Wouter PE4WJ for his neat telemetry program.
john heath wrote:
Hi,
Having fun here with Delfi and RASCAL. Keeping on tune and in sync is quite tricky though.
Using computer control via the CAT port the Yaesu FT847 seems to limited to 10Hz steps. When manual tuning the available steps are Normal 0.1, 1, 10 Hz. Default 1Hz ( page 23 in the manual)
Does anyone on the bb know if the CAT frequency step can be modified, perhaps by a hidden menu or similar.
BTW this 10Hz limitation seems to apply to the FT817 as well.
Its even worse... My ft817 seems to mute when given frequency commands via the cat interface. I have to tune it in steps of 100 to 200 Hz to minimize the amount of corrupted packets.
73, Jeroen
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
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: [email protected] [mailto:[email protected]] 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
_______________________________________________ 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
John,
There is indeed a 10 Hz limit on resolution in the CAT, set by the firmware. However, that should not be a problem. All the many TLM programs I have used in the past have worked well with 10 and even 100 Hz step sizes. My impression is that RASCAL could do with a little tweaking of the PLL values, but that may be more of an indicator issue. My experience is that is will in fact decode nicely, even though the Sync indication blinks off. FWIW
Alan WA4SCA
Yes,
The best thing to do is using a "free" program like Spectran (http://www.weaksignals.com/) to center the audio frequency around 1600Hz by fine tuning the FT-847. Rascal does the rest. Have used it now for several days and shipping frames to our Dutch friends.
Stefan, VE4NSA
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Alan P. Biddle Sent: May-03-08 8:18 PM To: 'amsat' Subject: [amsat-bb] Re: FT 847 and Doppler for Delfi
John,
There is indeed a 10 Hz limit on resolution in the CAT, set by the firmware. However, that should not be a problem. All the many TLM programs I have used in the past have worked well with 10 and even 100 Hz step sizes. My impression is that RASCAL could do with a little tweaking of the PLL values, but that may be more of an indicator issue. My experience is that is will in fact decode nicely, even though the Sync indication blinks off. FWIW
Alan WA4SCA
_______________________________________________ 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
participants (4)
-
Alan P. Biddle -
Jeroen Vreeken -
john heath -
Stefan Wagener