Satgen 148 Satellite Telemetry by GM4IHJ 26 Jan 92 Now that Dove has returned to 2m 145.825 MHz , all packet radio users have a simple to use,regular source of satellite experimental data. Just set up your two metre packet FM reception AX25 1200 bps as you do for terrestrial packet and between 0900 ut and 0100 ut , UK stations should hear Dove every 100 minutes or so ( ie 9 to 11 times). With best signals on the orbits just before noon , and in the late evening. Orbits around 1700 are polar passes , which are difficult to hear south of Yorkshire.You can use G3ZCZs excellent WHATS UP (IBM) software (available Readycrest Ltd Po Box 75 Chatham ME5 9DL ),to automatically decode Dove telemetry. This software will also decode all existing amateur satellites except , some pacsats and, the new RS12/13,RM1 and SARA. To learn more about receiving and using amateur satellite telemetry , the following books are available :- Title Source 1. Space Radio Handbook RSGB 2. Decoding Telemetry from Amateur Satellites AMSAT NA 3. Satellite Dove Operating Manual GM4IHJ 4. Uosat 3 and 5 Operating Manual (New Edition) GM4IHJ An SASE to the above will get you further details Books 1 and 3 give practical examples of experiments in Space Physics which can be done in your home station or classroom. Books 1 and 2 are very comprehensive , covering all amateur satellites except the new RS12/13 , RM1 and SARA. Book 2 is particularly good on the Pacsats ( be careful not to confuse it with another Amsat book called "Beginners Guide to Pacsat" , this "beginners guide" is not recommended ). Book 3 is specifically aimed at the Dove operator. Dove's telemetry is particularly useful for experiments which demonstrate satellite orbit features such as Period, Height, Eclipse timings , and the effect of these factors on satellite hardware, such as batteries and solar panels. Book 4 applies specifically to those equiped to receive the high speed 9600 bps from the highly efficient Uosat 3 and Uosat 5 birds. Telemetry decode for RS12/13 , RM1 and SARA is not covered in these books but it has been published on packet bulletins. Check with Amsat or your local BBS for copy, or "in extremis", packet or SASE GM4IHJ@GB7SAN. ************************************************ SUB HORIZON HF. RS12 continues to give long sub horizon extensions of coverage on Mode K orbits presently between 1300 and 2000 ut. RS12 over Japan has been accessible from UK on several recent UK afternoons , unfortunately very late pm in JA. Results in the UK afternoon 1300 to 1600 are also very good from Eastern South America , and appear possible to USA. Later around 1900 ut RS12 descending N to S east of UK well below US horizon nevertheless gives good subhorizon access for W stations to QSO Europe. Unfortunately US 29.4 MHz repeaters can make it nearly impossible. European stations are requested not to work these repeaters in satellite band section .Does ARRL approve these repeaters ? 73 de GM4IHJ @ GB7SAN