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Re: Difference between 9600 bps DFM Satellite and 9600 DFM Terrestrial



At 03:00 PM 2/18/2006 -0800, John Magliacane wrote:

>--- "Christensen, Eric" <CHRISTENSENE@ECU.EDU> wrote:
>
> > Maybe it is too early in the morning but I
> > can't fathom the difference between the two and why you would have to go to
> > the discriminator for one and not the other.
>
>Hi Eric.
>
>As far as I'm aware, there's no difference between satellite and terrestrial
>modes of 9600 baud FSK modulation.
>
>So, unless the manufacturer of the transceiver has already made the necessary
>provisions, direct connections to the transmitter varactor and receiver
>discriminator are required for proper 9600 baud FSK modulation/demodulation.

Hi Guys,

The IC-820 problem on 9600bps is only because of the ridiculous
way ICOM set up the SUB/MAIN band operation. When you select 9600BPS
operation, you get only the MAIN band audio but that is the uplink band!
For satellites, you need the audio from the SUB band. This is so silly you
have to wonder what they were thinking. Fortunately, this was fixed in
the IC-821 and you can mod the IC-820 to get the SUB rx audio to use
9600 for satellites with a relatively easy mod.

73,
Tony AA2TX
----
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