Linux-Hams archive - December 1999: Re: Off the shelf 9k6 and 19k2.
Re: Off the shelf 9k6 and 19k2.
Jose R. Marte A. (gfgdg@va.us)
Sat, 11 Dec 1999 00:02:02 -0400
> From: Bob Nielsen <gunxuhdv.qmmtttvxwq@permlinks.com>
> To: hzjidg@mailit.tunk.net
> Subject: Re: Off the shelf 9k6 and 19k2.
> Date: Friday, December 10, 1999 6:40 PM
>
> On Thu, Dec 09, 1999 at 08:55:48PM +0100, Thomas Sailer wrote:
> > Bob Nielsen wrote:
> > >
> > > On Wed, Dec 08, 1999 at 03:45:40PM +0000, Patrick Ouellette wrote:
> > >
> > > > Most of the newer mobile radios from the major manufacturers
include
> > > > 9k6 ports.
> > >
> > > Have you found any of these to actually work (low BER, txd < 30 ms or
> > > so)?
> >
> > Good question. Henning DF9IC has measured a couple of mobile
> > transceivers
> > claimed '9k6 capable' about 3 years ago, and none was satisfactory.
> > I've heard of new allmode transceivers (one ICOM model) that works well
> > with 9k6, that is however >$2000.
>
> That was my point. I believe QST came to a similar conclusion. The
> allmode transceivers tend to use a heterodyne scheme for transmit so
> that you modulate a crystal oscillator stage rather than the PLL. As I
> recall, an early Azden FM transceiver did this as well and had
> reasonable 9600 performance.
I have one, AZDEN model 4000 FM Transceiver at 9k6 and it is working
pretty well with the TXD 10ms, not problem very low retries with the
KPC9612+
>
> Otherwise there is a trade-off between poor frequency response (fast
> PLL time-constant) and poor T/R switching times (slow PLL
> time-constant). There are ways to compensate for the frequency
> response, but it's a bit tricky and may not be all that stable in a
> production-line radio.
>
> TEKK and some other data radios work fairly well, as do some converted
> crystal-controlled commercial radios, such as Motorola Mitrek.
>
> >
> > In the end you're probably better off with dedicated designs like
> > the T7F kit by Holger Eckhardt.
>
> Do you have a URL for this?
>
> Bob
>
> --
> Bob Nielsen, W6SWE (RN2) Internet: vyocsk.enugfknin@a-net.ne.jp
> Tucson, AZ DM42nh AMPRnet: qttjyet.npepgwx@uab.edu
> QRP-L #1985 http://www.primenet.com/~nielsen
73's Jose (hi8gn)
trpaipt@ce.nbp.pl
http://hi8gn.dynip.com/