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Radio Astronomy Supplies' Hydrogen Line Radio Telescope

While SETI League engineers are hard at work developing specialized, dedicated SETI receivers, a number of our members are anxious to quickly join The Search. One expedient is to adapt existing wide-band radio telescopes to the SETI mission. Although it is limited in frequency coverage to the lower part of the Water-Hole, the Hydrogen Line Radio Telescope sold by Radio Astronomy Supplies is a viable alternative.

Developed by microwave engineer and radio amateur Carl Lyster, this rack mounted system includes a low-noise preamplifier of approximately 28 dB gain and .37 dB NF (26 degrees Kelvin noise temperature), a cylindrical waveguide feedhorn with a monopole probe, a dual conversion crystal controlled downconverter from 1420 MHz to a 70 MHz IF, and an IF/square-law detector unit with 30 MHz bandwidth and integration times variable from 0.01 to 10 seconds. All but the latter assembly appear suitable for amateur SETI at or near the Neutral Hydrogen Line. In addition, an audio output function has been built in.

SETIphiles wishing to adapt this receiver design may wish to employ the preamplifier, feedhorn and/or downconverter portions, followed by a narrow-band VHF receiver capable of tuning between about 55 and 85 MHz. This will enable you to search within plus and minus 15 MHz of the Hydrogen Line, for interesting signals of possible extra-terrestrial origin. If you obtain the IF unit as well, it can be used for conventional radio astronomy when you're not engaged in SETI. In fact, with a simple BNC T-connector in the 70 MHz port, it should be possible to do both narrow and wide bandwidth searches simultaneously.

The system described here is currently priced at $1499.00 . A Data Sheet is provided here for your convenience. In addition, Radio Astronomy Supplies offers a research grade, highly sensitive Hydrogen Line Spectrometer. This is the SpectraCyber. This system has the capability of Spectral and Continuum channels. For SETI League members, they offer this system at a discount for: $2295.00 plus shipping. See

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