SETI League Technical Manual -- Receivers
Editor's Note: See this article for information on how to generate your own custom radio frequency interference (rfi) database using the SETIFOX digital signal processing program.All heterodyne type receivers are subject to various forms of internal and external interference, and the ICOM receivers popular for SETI are no exception. SETI League member Alfred A. Aburto Jr. has tested an ICOM model IC-R7100 reciever to determine its internally generated interference profile.
Al's test was performed by removing the antenna from his receiver, and scanning its entire frequency range (25.000 MHz to 1999.995 MHz) in 5 kHz steps, in USB mode. He recommends that members building SETI stations prepare a similar interference database for any receivers which they might happen to be using, so that signal analysis software can be "trained" to eliminate known interference from consideration.
| Frequency | Audio Output |
|---|---|
| 101.435 MHz | tone, garble |
| 119.085 MHz | |
| 121.500 MHz | tone |
| 133.905 MHz - 133.920 MHz, | tone |
| 164.300 MHz | tone |
| 185.750 MHz | garble |
| 197.745 MHz - 197.755 MHz | garble |
| 223.900 MHz | tone |
| 241.735 MHz | tone |
| 252.435 MHz | tone |
| 256.000 MHz | buzz |
| 266.700 MHz | tone (low freq) |
| 266.705 MHz | tone (high freq) |
| 294.930 MHz | tone |
| 307.200 MHz | tone |
| 326.300 MHz | tone |
| 333.330 MHz | tone |
| 343.205 MHz | |
| 369.100 MHz | tone |
| 441.105 MHz - 441.120 MHz | |
| 460.800 MHz | tone |
| 471.500 MHz | tone (low freq) |
| 471.505 MHz | tone (high freq) |
| 477.250 MHz | buzz |
| 481.750 MHz | garble |
| 490.600 MHz | tone |
| 512.000 MHz | buzz |
| 621.220 MHz | tone |
| 621.235 MHz | tone |
| 621.250 MHz | buzz |
| 625.750 MHz | garble |
| 693.190 MHz | tone |
| 693.205 MHz | tone |
| 693.220 MHz | tone (loud) |
| 693.235 MHz | tone (loud) |
| 693.250 MHz | tone (loud) |
| 693.300 MHz | tone |
| 693.315 MHz | tone |
| 693.330 MHz | tone |
| 693.345 MHz | tone |
| 697.735 MHz - 697.765 MHz | garble |
| 716.800 MHz | tone |
| 733.745 MHz - 733.760 MHz | garble |
| 735.900 MHz | tone |
| 746.600 MHz | tone |
| 768.000 MHz | tone |
| 801.250 MHz | tone |
| 805.745 MHz - 805.755 MHz | garble |
| 929.940 MHz | intermittent tones |
| 931.110 MHz | BB noise |
| 931.285 MHz - 931.295 MHz | intermittent BB noise |
| 931.535 MHz | tone |
| 953.105 MHz - 953.120 MHz | tone |
| 1002.600 MHz | tone |
| 1024.000 MHz | buzz |
| 1055.555 MHz | tone |
| 1111.115 MHz | tone |
| 1119.085 MHz | tone |
| 1121.500 MHz | tone |
| 1147.535 MHz | tone |
| 1164.300 MHz | tone |
| 1164.305 MHz | tone |
| 1166.670 MHz | tone (loud) |
| 1222.225 MHz | tone (loud) |
| 1241.735 MHz | tone |
| 1252.435 MHz | tone |
| 1266.700 MHz | tone |
| 1277.780 MHz | tone (loud) |
| 1333.335 MHz | tone (loud) |
| 1369.100 MHz | tone |
| 1388.890 MHz | tone (loud) |
| 1441.105 MHz | tone |
| 1444.445 MHz | BB tone (loud) |
| 1471.500 MHz | tone |
| 1477.250 MHz | BB tone |
| 1481.750 MHz | garble |
| 1500.000 MHz | buzz |
| 1512.000 MHz | tone (low freq) |
| 1536.000 MHz | tone |
| 1555.555 MHz | BB tone |
| 1611.115 MHz | BB tone |
| 1621.220 MHz | tones (low level) |
| 1625.740 MHz - 1625.765 MHz | garble |
| 1666.670 MHz | tone (loud) |
| 1686.405 MHz - 1686.420 MHz | tone |
| 1722.225 MHz | tone |
| 1735.900 MHz | tone |
| 1768.000 MHz | tone (low freq) |
| 1777.780 MHz | tone (loud) |
| 1792.000 MHz | tone |
| 1833.335 MHz | tone |
| 1881.100 MHz | tone |
| 1888.890 MHz | tone |
| 1931.535 MHz | tone |
| 1944.445 MHz | tone (loud) |
| 1953.105 MHz - 1953.120 MHz | garble |
| 1977.735 MHz | BB tone |
| 1978.600 MHz | BB tone |
| 1978.605 MHz | tone |
| 1988.700 MHz | tone |
| 1999.550 MHz | tone |
| 1999.920 MHz - 1999.995 MHz | BB noise increases greatly |
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