[amsat-bb] Re: Satellite's

[Mike Seguin N1JEZ]

Hi Tom,

The "uplink" connection in the panadapter seems to be the missing piece 
right now, but truthfully, I have not looked lately to see what's available.

I can tell you that HDSDR and Omni Rig work well with the FT-817 and the 
FUNcube. In HDSDR, the tuning controls the FT-817 (and tuning the FT-817 
manually updates HDSDR) and behind the scenes, HDSDR locks the FUNcube to 
68.33 (or whatever you set it to use - I use 68.32 to get away from the DC 
offset spike). But, no doppler control.

I guess if I were going to do it, I'd tap the common IF of my FT-847. Then 
use SatPC as usual to control the 847 and HDSDR to just display the FUNcube. 
I wouldn't have full integration, but I'd be able to see most of the 
passband and could simply tune the 847 to receive the downlink. SatPC would 
compensate for uplink Doppler.

I could probably do the same with an FT-817 or two of them....

Having the ability to see other signals in a +/- 40 kHz window (for those 
weak signals off frequency) was the big plus for us working microwave and I 
could see it being a big help in satellite work as well.

73,
Mike, N1JEZ
AMSAT 29649
"A closed mouth gathers no feet"



----- Original Message ----- 
From: "Thomas Doyle" <tomdoyle1948 at gmail.com>
Subject: Re: [amsat-bb] Re: Satellite's


> Hi Mike,
>
> I have two radios that have a built in panadapter and have used the
> dongle as a stand alone panadapter. The problem is all the panadapters
> I have used or read about, other than SDR based gear like the Flex
> radios, do not have a connection between the panadapter and the
> frequency control of the radio. With an SDR receiver you click on the
> waterfall or spectrum display and the radio is tuned to that
> frequency. That is what I am trying to do and that bit you get for
> free with an SDR receiver the hard the part I am trying to solve is
> controlling the transmit frequency (including doppler correction and
> offset) when using linear sats. The only way I have been able to do
> this so far is to use SDR-Radio with its built in doppler correction
> for the receiver and my IC-7000 as a transmitter under the doppler
> corrected frequency control of SatPC32. This works but changing the
> frequency on the SDR does not adjust the transmit freq. I am hoping
> someone has actually done this as I have never been a big fan of
> reinventing the wheel.
>
> The FT-817 is a very cool rig and I will be very interested to see how
> you control the FT-817 frequency from the panadapter - that is the
> tricky bit since the panadapter does not have to even know what
> frequency you are receiving. It should be possible to poll the
> panadapter for the offset of the frequency you have clicked on and add
> that to the FT-817 frequency and feed it back into the FT-817.   I am
> sure you guys have come up with something. Thanks for writing the
> article. I look forward to reading it.
>
> 73 W9KE Tom Doyle
>
>
>
>
>
> On Wed, Aug 29, 2012 at 9:18 AM, Mike Seguin N1JEZ
> <n1jez at burlingtontelecom.net> wrote:
>> Hi Tom,
>>
>> There will be an article coming up in the AMSAT Journal on work that 
>> W1GHZ,
>> W1FKF and I have done on tapping the common IF in the FT-817 and using 
>> the
>> FunCube as a Panadapter. Our primary application is weak signal 
>> microwave.
>>
>> I would think it would work well for satellite. That way your software 
>> would
>> be controlling an FT-817. The common IF is centered on 68.33 MHz in the
>> FT-817, so you see +/- 40 kHz around that. You would be able to take
>> advantage of all the front end filtering in the FT-817.
>>
>> 73,
>> Mike, N1JEZ
>> AMSAT 29649
>> "A closed mouth gathers no feet"
>>
>> ----- Original Message ----- From: "Thomas Doyle" 
>> <tomdoyle1948 at gmail.com>
>> Subject: [amsat-bb] Re: Satellite's
>>
>>
>>> I am close to a SatPC32 <-> dongle system but there is probably
>>> someone with a much better 'simple' or even a 'very simple' solution.
>>> I would be very interested in hearing from anyone who has actually
>>> achieved fully synchronized doppler corrected transmit control with a
>>> dongle for the receiver. A reply offline would be best to prevent
>>> flames.
>>
>>
>>
>
>
>
> -- 
>
> Sent from my computer.
>
> tom ...
>