> From: Bob Nielsen <[EMAIL PROTECTED]> > To: [EMAIL PROTECTED] > 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: [EMAIL PROTECTED] > Tucson, AZ DM42nh AMPRnet: [EMAIL PROTECTED] > QRP-L #1985 http://www.primenet.com/~nielsen 73's Jose (hi8gn) [EMAIL PROTECTED] http://hi8gn.dynip.com/
