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From: "Vernall" <vernall@xtra.co.nz>
To: rsgb_lf_group@blacksheep.org
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Subject: LF: Re: RE: Transcontinental modes - what next?
Date: Thu, 8 Mar 2001 08:32:29 +1300
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Alberto

> Hi all,
>           which would you all prefer as a way to frequency-shift your TX ?
> With frequency shift I mean many steps, separated by a fraction of an
Hertz.
> The first two possibilities that come to my mind are an audio output from
the
> sound card (requiring then a mixer to bring the tone to the wanted freq.),
> or a binary value output from, say, the parallel port, which then would
require
> a small external board with a DDS or a microcontroller to drive the TX.
>
> No linearity requirements will be needed. I need your input to not start
in a
> false direction.    TNX for any advices.

My preference is to transceive via a PC sound card, and use the likes of an
SSB transceiver, i.e. very little different to practices for HF digital
modes, except much longer message times.  When fine tuning is available on a
sound card, it is a very convenient way to arrange for quite accurate LF
carriers.

73, Bob ZL2CA