[MarinTeams] QRP SSB Project

[Bill Smith]

Hi, all

We are borrowing a reflector once set up for local communications practice in Marin.  The list has been otherwise inactive and so we can use it for the SSB project.

Please send mail to marinteams at mailman.qth.net.  It will be distributed to other members who have expressed interest in the project.  So far they are:

Peter Bland K6AJB        San Rafael, CA
Rod Rigg    NNN0VNW  Stockton, CA
Paul Kitagaki  NNN0AEX  South San Francisco, CA
David Hirtz    NNN0UFV   San Francisco, CA
Bob Buck     NNN0LHO   Las Vegas, NV


The project information for the SSB transceiver (80 meters) can be found at:

http://www.qrp.pops.net/Idaho.htm

This is an open experimentation project, that is you can choose to do anything you think will work for you!  :-)   It is work in progress, as a device of this kind has not been assembled except for the PSK devices offered by http://www.smallsonderslab.com.  

Small Wonders has discontinued the 80 meter PSK-31 transceiver, but offers 40 and 20 meter kit versions for $150.  This may be attractive if your budget can adsorb the cost.

The concept is to build a low-cost portable digital low power station that is PSK-31 and/or MT-63 capable.   Both modes require SSB transmission capability in order to maintain proper signal phasing and transmission envelope.  The qrp reference above seems to be the lowest cost SSB approach found so far.  If you discover a better circuit, please feel free to let us all know.

Another alternative is the DSS (digital signal synthesis).  Development work is underway and information may be available on the net.  If you poke around on Internet and find anything interesting, please let us know.  This would be the preferred transceiver approach.

Paul brought up the issue of frequency stability.  Generally a crystal controlled transmitter will not have 10Hz stability unless controlled by a TXO (temperature regulated oscillator) device.  But most of our transceivers used on the MARS net don't maintain this stability either.

Terminal devices (the unit that can type and display ASCII characters) can be either one of the Palm Pilot models, or a laptop.    If you have a laptop, you can use the several soundcard programs that have been recommended on the PA1C net.

Terminal software ($39.95 or was it $29.95?) is available that will run on many of the older Palm Pilot devices.  Palm is selling reconditioned Palms for low prices (see their website).  However, a TNC device will still be needed.  Likely this will rule out MT-63 as there doesn't seem to be a hardware decoder/encoder for that mode.  However, there may be PSK-31 software written for some of the Palm models, and there is also a dedicated TNC for PSK-31 available.  

Specific URL's covering this information will have to be "rediscovered" through search engines if there is any interest in the Palm approach.  I was originally very interested in the Palm, but have since obtained an old laptop.   Actually, used laptops appear to be available at swapmeets for $50-75 and up, which is about the same price as a used Palm.

Please feel free to offer any suggestions, discoveries, comments!

73 de Bill, NNN0BIO/AB6MT
billsmith at ispwest.com


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