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Re: SDR-1000 (was FT-847 discontinued?)



There is a processing delay on receive. This is a limitation of the
operating system used for signal processing.

73,

John
KD6OZH

----- Original Message -----
From: "John P. Toscano" <tosca005@tc.umn.edu>
To: <amsat-bb@amsat.org>
Sent: Friday, December 16, 2005 00:46 UTC
Subject: Re: [amsat-bb] SDR-1000 (was FT-847 discontinued?)


> Dave G. wrote:
>
> > The problem for high speed CW lies in the inherent delay with
> > the DSP processing algorithms. IMHO because of that delay
> > it's not yet a serious contest rig YMMV!!
>
> Dave (or anyone else on the list who knows):
>
> Is the "slow" CW speed only a function of computer-generated CW?  If so,
> couldn't you get around that problem by using an external keyer?  The
> MFJ-495, for example, allows you to send CW via straight key, paddles, a
> PC keyboard plugged directly into it, or via a serial data stream from a
> computer.  It handles speeds up to 990 WPM (or so they say), which
> oughta be fast enough for almost anyone.  :)  (Heck, if I could reliably
> work CW at a "mere" 20 WPM I'd be ecstatic!)
>
> Or is the SDR not able to send fast CW even if it doesn't have to
> synthesize the CW from keyboard commands on the same PC that is
> supporting the digital encoding/decoding process?  It just seems odd to
> me that it could encode voice into an SSB or AM or FM signal, but simple
> "on/off" sequences of Morse code would be hard for it to do...  But I'm
> certainly very uneducated (at least so far) about the whole SDR DSP
> process, so maybe I'm way off base...
>
> If the problem is the delay between hitting the dit or dah side of the
> paddle and the time that you hear feedback from the monitor speaker, it
> should be possible to listen to yourself send only from the output of
> the keyer, and have the SDR not echo what you send back to your ears.
> Then, it doesn't matter if it takes an extra 300ms for your CW to finish
> transmitting before the person on the other end can respond.
>
> Or am I still missing something totally?  (These are honest questions,
> I'm not trying to take pot shots at anyone, I really don't know the
> answers to them.  Since I've been tempted to step into the SDR-1000
> world "one of these days", I'd really like to know more about it.)
>
> 73 de W0JT
> ----
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