Home Satellite TV Receivers

To receive APT transmissions from the NOAA weather satellites, you require a receiver. The satellites transmit their datastream in the 137 MHz band using frequency modulation (FM). Although you can listen to their 'tick-tock' signature using a fairly inexpensive scanner and whip antenna such a system will not enable the reception of good images.

The reason for this apparent anomaly is due to the bandwidth of the signal. Most scanning receivers have available FM bandwidths of either 150kHz, for FM broadcasts, or about 5kHz for amateur or mobile service transmissions. Weather satellite signals require a bandwidth of 40kHz - 50kHz to accommodate the signal itself plus the Doppler effect. The Doppler effect is identical with the familiar change in pitch of a police car siren as it approaches then recedes from you - initially high pitched, becoming lower as the satellite firstly approaches the listener, flies overhead, then recedes again, this variation is added or subtracted to the signal thus widening its bandwidth.

Therefore a specialised receiver is necessary.

Options

R2ZX APT Receiver

Full computer control, WXtoImg compatible. Twin antenna sockets for diversity reception - automatic selection of the strongest signal. Fully cased and ready to go.
A 'hardened' version of the R2FX having exceptional resistance to the in-band pager signals plaguing APT users in the UK.

Alternatives found on the web

The Kosmek receiver is part of a complete APT receiving system designed by the VFS (Vision From Space) group in the Ukraine. It can be operated stand-alone or by computer control by serial port link. More

Wrasse WeSaCom APT-06 Weather Satellite Receiver. Now available with antenna diversity.
More

The Antenna

The signals from the NOAA weather satellites are transmitted with right-hand circular polarisation. There are two common solutions to this problem, the crossed dipole (or turnstile) and the quadrifilar helix (QFH) antenna (in each case, designed and tuned specifically for the 137 MHz band).