Receiving the ARISSat-1 CW (Morse Code) Signal
In addition to several general transmission modes such as FM, SSTV and BPSK-1000, ARISSat-1 also broadcasts a telemetry subset in CW or continuous wave mode. The CW transmissions are broadcast in Morse code. If the BPSK-1000 digital telemetry is being sent at 145.920 MHz, CW telemetry will be transmitting on 145.919 MHz. If the BPSK-1000 system were to fail, then telemetry would be transmitted by the BPSK-400 backup system and CW telemetry will be sent at 145.939 MHz.
Deciphering Morse code
Listeners that are interested in receiving and deciphering the CW transmissions can find a Morse code chart at http://www.arrl.org/learning-morse-code.
To receive ARISSat-1 CW signals, you will need a radio that can tune from around 145.916 to 145.942 MHz and has a mode switch for CW reception. Radios to consider would be certain types of ham radio receivers and scanners with the features just mentioned. Some typical radios equipped to receive CW signals are the Icon R-20-06, Kenwood TH-F6A and Yaseu FT-817 ranging from $300 to $700 new. The Icon R-10, replaced by the R-20-06, may be found on sites such as www.ebay.com. A software defined radio or SDR can be purchased at www.funcubedongle.com as available. This device allows you to convert your computer into a satellite receiver using the computer soundcard and external software such as SpectraVue, see www.moetronix.com/spectravue.htm. Radios, such as those mentioned above, can many times be found at local hamfests. These are events where ham operators gather to trade for or purchase new and used ham gear. Ham receivers with the ability to receive ARISSat-1 may be available there at bargain prices and in good condition. Searching the internet for hamfests in your region or state is a good way to locate these events.
The output power level of CW signals from ARISSat-1 is 25 mW; therefore, receiving the signal will most likely call for an outdoor external 2 meter band antenna. A beam antenna would be preferred since it offers an improved receive signal level over an omni-directional antenna when pointed at the satellite. The Arrow Model 146-3, 3 element 2 meter handheld beam antenna is a good choice. This can be found at http://www.arrowantennas.com/arrowii/146-3ii.html.The Elk Antenna Model 2M/440L5, found at www.elkantennas.com is another beam of choice. This is capable of both 2 meter and 70cm band operation and can be used for reception of ARISSat-1 and operating other amateur satellites. If you would rather construct your own 2 meter beam to receive ARISSat-1, searching the internet for “homebrew” 2 meter beam antennas should yield a number of possibilities.
Configuring your CW Receiving Station
Once you have acquired your radio receiver and antenna, you are ready to assemble your station. This is simply a matter of connecting your antenna to the receiver’s external antenna input. This would require a length of 50 Ohm impedance coaxial cable. For relatively short lengths, under 50 feet, RG-8X is a good choice since it is light, flexible and has a small diameter. If a length greater than 50 feet is required, consider using LMR-400 UL. This is a larger coax, but still retains some amount of flexibility and low signal loss. These are just suggestions and there are other comparable coaxial cables available.
Another handy device to add would be a digital audio recorder. Recording CW during a satellite pass enables you to copy the code transmissions as they happen, and also review them later for any part of the transmission you might have missed during the pass. Portable digital recorders are usually available at local electronic and office supply stores.