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Re: 38k4 questions



Hi Steve,

My IFD seems to work perfectly in a FT-736R!!

I did have trouble with the initial installation -- when I tightened the nut
on the steel stand-off next to L17, the inductor jumped off the board.
Either the board wasn't perfectly flat or my stand-off mounting was off a
little.  The second time I was able to carefully solder it back on and leave
the nut off of that stand-off.  And it now works as advertised!!  I would
recommend plastic stand-offs.  ;-)

One thing that I found through experimentation is that the center frequency
for best data through-put is about 16KHz lower than it should be.  I set my
TrakBox for 437.384MHz and I now get better than 90% with the best downloads
over 2MB.  With the frequency set for 437.400MHz I only get good data with a
signal over S9 with downloads about similar to the 9600 birds.

Unfortunately, we haven't had a pass since the 16th so my experimentation is
on hold.  :-(

Let me know if I can answer any specific questions about the installation.

73  Tom  n0ntx

----- Original Message -----
From: Diggs, Steve <Diggs@daugherty.com>
To: 'Mark L. Hammond' <hammond@surrealnet.net>
Cc: 'amsat-bb@amsat.org' <amsat-bb@AMSAT.Org>
Sent: Friday, June 23, 2000 09:34
Subject: RE: [amsat-bb] 38k4 questions


> Hi Mark,
>
> 1. Stacey Mills, the author of the 38k4 article in QST, uses a TS-790.
> 2. Not sure. Ask Stacey. (w4sm@amsat.org, I think)
> 3. It does not lend itself to more-narrow band modes. Too noisy for 9600,
> but it does work. Definitely out for 1200. (WAY too much noise)
> 4. The first and foremost test of successful installation is...do all
> existing functions work as well as they did before installation? Mine did,
> and on top of that I got a 1-2 db increase in sensitivity, as stated in
the
> IFD docs. Bottom line: nothing negative, maybe even a bit positive.
>
> For me the kicker has been to get it to work at 38k4. I have a FT736r, and
> can't get the IFD to produce a stable audio out. The install seems to have
> an internal ground loop that causes the audio out to have a stutter-like
> noise that is clearly evident in the noise pattern. Symek says the darn
> thing works perfect in a 736, but I have *yet* to hear someone other than
> Symek to get it to work on a FT736r. That leads me to believe that the
> instructions are missing some key element.
>
> If anyone has successfully completed an IFD install in a FT736r, I'd love
to
> hear from you!
>
> Regards,
> Steve Diggs, W4EPI
>
> -----Original Message-----
> From: Mark L. Hammond [mailto:hammond@surrealnet.net]
> Sent: 6/22/2000 8:37 PM
> To: amsat-bb@AMSAT.Org
> Subject: [amsat-bb] 38k4 questions
>
>
> Hello all,
>
> I'm dreaming about 38k4 operations.  Some questions come to mind:
>
> 1) anybody on the list mod their Kenwood TS-790  with the Symek F-IFD
unit?
>
> 2) do the transformers necessary for the mod come with the F-IFD?
>
> 3) does integration of the F-IFD still permit digital operations at 1200
> and 9600?
>
> 4) what effect (if any) does the F-IFD have on SSB operations?
>
> Thanks for any input,
>
> Mark L. Hammond  [N8MH]
>
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