Summery

My satellite receiving station consists of a 3' offset satellite dish, a turnstile antenna with preamp, two receivers, an interface, and a computer running PROSat for Windows. Lets take a look at each component.

Dish and Turnstile Antenna with Preamp

The dish receives Meteosat-7's WEFAX signal. I just got this system last year, and since WEFAX is yeilding to Digital High Resolution imagery in a few years, I opted for an inexpensive way of receiving the images. There is an active feed on the dish that sends the 1691 MhZ signal to a downconverter. The downconverter steps the signal down to a frequency of 137.500 MhZ so that it may be sent to the receiver without an expensive preamp. There are two downfalls to my system. One is the signal is slightly degraded by the Active Feed and Downconverter. The second pitfall is it is difficult to receive the second data channel, which transmits relays from other satellites around the world. The preferred way of receiving these images is with a dedicated dish, preamp, and receiver all made for this type of reception.

The Turnstile antenna is pretty simple. It's not the best on the market, but it does a good job. The antenna is about 20' off the ground, but because my house is surrounded by trees I cannot receive a reliable signal until the satellite is about 7 degrees above the horizon. There is a preamp on the antenna that amplifies the signal before it makes the trip down the feedline to the receiver. The Preamp can be good and bad. In my situation, it does a lot of good because it hepls the antenna pull the signal out of the trees during low passes. A preamp can be bad because that increase in sensitivity can introduce interferrence into the signal. If you're thinking of assembling an APT receiving station, try it without the preamp first. That way, if your reception is good, you would not have wasted the money on a nonessential piece of equipment and/or introduced interferrence.

Receivers

The Meteosat receiver is a Multi-Fax MF-R1 APT receiver. I like this receiver because it sends enough power up the signal cable to power my Active Feed without running a seperate power cable outside. Although it is an APT receiver, I would not recommend it to APT reception. The Active Feed sends a strong signal down the cable and on a constant frequency. This receiver is terrible for receiving weak signals.

The APT receiver is TimeStep's PROScan Receiver. It is one of the best on the market, and probibly the best prebuilt model available to amateurs. The receiver is controlled by the Interface during APT reception.

The i Interface

This component does the receiver switching and all the image processing. Both receivers are plugged into the interface and, depending witch image that is to be received, selects the receiver, decodes the image, and sends it to the software. The only complaint I have about the interface is it cannot receive both APT and Geostationary signals at the same time. This means that when I'm receiving an APT image, Meteosat Reception is suspended. It does, however, have one major benifit in my system. It controlls the APT receiver for proper reception. See the APT Section for a complete explanation