Polar Operational Environmental Satellites cover
the earth four times daily. When satellites
pass within the receiving range of the weather fax receiver a "APT"
Transmission signal is sent to the
computer through the sound card and encoded with software to create
Receiving NOAA satellite images require a Weather Satellite fax receiver, antenna, computer with sound card and software to encode the satellite signal.There are several receivers, antennas and software available. I decided to use the Hamtronics R139 receiver, National RF WX-137Q TURBO-TENNA, and WXtoimg software after reading several recommendations on various weather web sites.
Hamtronics R139 Receiver
Misc Jacks, Switches and Wire
|Below is the LNP-137 Preselector from Hamtronics. This units helps to eliminate any interference caused by nearby transmitters and is placed between the antenna and receiver. Hamtronics also sells the mini coax cable and special RCA connectors.|
project box allowed for all wiring to the R139's DB9 connector without
having to cut off the connectors from the power supply and audio cable,
which makes for easy disassembly when needed. Also the LNP-137 preselector was enclosed.
The 8 ohm load resistor is wired to the speaker switch so the recording volume will not be affected when switching the speaker on and off while recording is taking place.
60 Hz interference problem
The following information is with thanks from Tom of Tabaccovilleweather.com.
It was Tom who figured out how to solve this problem.
After seeing numerous images that showed signs of 60 Hz interference,(wavy lines in images),
I decided to add a audio isolation transformer between the audio output of the R139
and the audio input of the sound card. It seems to be helping quite a bit so far.
The Audio Transformer is Radio Shack part No. 273-1380
|Back of the project showing all the connectors.|
|Front of the project box. Speaker mounted on top. Speaker switch with LED.|
|Project box with Hamtronics R139 receiver.|
I decided to add the Hamtronics LNK-137 FET Preamp to my setup.
The cable is over 50 feet in length from the antenna to the receiver.
It's recommended to use a preamp in this situation.
And my friend Tom from Tobaccovilleweather.com
said it should help to improve reception. He was right!
The preamp is mounted inside 2" X 8" PVC tubing them mounted to the mast.
The bottom cap was sealed with caulk to prevent water from entering.
The top cap was slipped on and secured with a stainless steel screw which
would allow for disassembly if repairs are ever required.
National RF WX-137Q Turbo-Tenna
(Backup antenna system if needed)