Built a NOAA APT system?

[MGCJerry]

I've been researching for awhile now on building an APT system to receive NOAA satellite images. However one of the most important things with the whole setup is the antenna. Based on what I've read, a quadrifilar helix (qfh) antenna gives the best performance. Has anyone setup an APT system and can offer some pointers before I start. My other issue is getting a cheap radio that can tune to 137Mhz and may end up going with a 2nd hand scanner even if I have thought about building my own receiver.

Thanks for any advice and pointers in advance.

[niko]

Long time since I looked at APT, but as I recall the bandwidth of most regular scanners will be too narrow for it.

[Silversword]

Hi,

I used to use NOAA APT satellites back in the early 1990's.  I used a Bear Cat scanner but had to modify the filter as this link shows http://www.uvm.edu/~swarley/bc210.htm to increase the bandwidth.  I used a turnstile antenna with a pre-amp.  I forgot where I bought it from or even if that person still exists. It was build on a 2" PVC pipe with two dipoles on top and about 8 ground plane radials on the bottom. A quadrifilar helix (qfh) antenna should work better but kinda pricey. The capture hardware and software might be another issue unless you have all this in place.

Guess that you could Google for QFH and turnstyle and get results in making a home brew antenna.

Good luck with your project.

--Stan Y.
  Maui, Hawaii

[niko]

Good stuff Stan, I see plenty of cheap BC210's on ebay. I built a helix once but it was challenge 

[Weather Display]

I used to have a GMS receiver and satellite dish and a WEFAX software program
I set it  up to be auto
was cool watching the latest satellite image come in like a fax every hour
i got the wife to walk around the lawn with the satellite dish....actualy that might have been before we got married...

[Stronghurst]

I am running a full blown NOAAport 3.8 meter satellite system

Mark

[N7XSQ]

An excellent APT site is:

http://poes-weather.com/

They have superb free APT decoding software.  In the Articles box at the right of the home page, they have links to receiver and antenna articles.  The double cross antenna works nearly as well as a quadrifilar, and is much easier to build.  For best results, you will need a receiver with a wider bandwidth than a scanner, but if you already have a scanner, it can work in a pinch until you get something better.

Ham radio folks have recently discovered that certain European DVB-T dongles (USB tuners for European digital TV) can be used as an inexpensive front end for a software defined radio that covers 60 - 1700 mHz, with a few gaps, when used with appropriate SDR software in the PC.  Most SDR software has user definable bandwidth, so this could work well for APT.  These dongles used to be $10 on e-Bay, but since this new use has been found, they have gone up to $20-$30.  You want a DVB-T dongle that uses the RTL2832U chip with an E4000 tuner.  Google RTL-SDR and RTL2832 for more information.  You would probably need one PC for the SDR software and another for the APT decoding software.  Here is a link to my current favorite RTL SDR software, although since this is pretty new, things change rapidly.

http://sdrsharp.com/

Steve

[Silversword]

Garth Bock posted this on the WXForum that is kinda interesting.

http://www.instructables.com/id/Downloading-NOAA-satellite-images-cheaply-and-easi/

--Stan Y.
  Maui, Hawaii

[Stronghurst]

Cool  Thanks for sharing.  This looks A LOT cheaper than my setup

Mark