400 bps PSK P3 Data Demodulator PCB


Introduction
The Phase IIID satellite currently under development [launched 2000 Nov 16 and now called OSCAR-40] uses a 400 bps PSK block-oriented format for engineering telemetry because a widespread ground station network is already in place from previous Phase III spacecraft missions.

The Amsat Oscar-10 and Amsat Oscar-13 (AO-13) satellites transmitted continuously at 400 bps using PSK. The information available was, most importantly, plaintext bulletins with up-to-date operational information. In addition there was full housekeeping telemetry giving transponder status, navigation, power and temperature data.

The original "AO-10 Data Demodulator" was introduced in 1984, and featured in Ham Radio (US), Wireless World (GB), Radio Rivista (I) and elsewhere. Its function was to take the AO-10/ AO-13/ AO-21 satellites' beacon audio and output an RS232 or parallel digital stream to display software for the IBM, Acorn Risc, Atari, BBC, CBM64, Spectrum etc families of computers. About 800 MK I PCBs were sold.

Over the years I maintained a wish list of improvements based on my own observations, and feedback from users. When stocks of the MK I demodulator were finally exhausted in 1992, I embarked on a substantial redesign, now known as the Phase 3 Data Demodulator, which incorporates the entire list.

Features

 PCB_PHOTO

It is a load-and-go design. There are absolutely no set-ups, no pots, no tune- ups. If you build the board properly it will work right-off; audio in, RS232 out. You don't need test equipment unless you want to explore its workings (or fault find). All you have to do is tune in the P3D satellite beacon until the LEDs light properly. Auto-tuning keeps the radio on-tune thereafter.

Optional Analogue to Digital Converter Upgrade Kit

Software for AO-40 telemetry display.

AO-40 telemetry archive.

AO-13 telemetry archive.

400 bps PSK P3 Data Demodulator Prices:

   Bare PCB board & instructions: £25 (UK/EU), £27 rest-of-world, air mail
   Made-up and tested board:      £95 (UK/EU), £99 rest-of-world, air mail
   Prices include postage and packing. Methods of payment

   Stock Remaining as of date below:
     Made-up and tested board: 9 units
     Bare PCB board:           3 units
50% of PCB net proceeds are pledged to Amsat.

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Last updated: 2010 Oct 16