Quadrifilar Helix Antenna for the 137MHz APT weather satellite band

Quadrifilar Helix Antenna for the 137MHz APT weather satellite band

The absolute beauty of amateur radio is that it is not a single hobby it is virtually limitless in scope. When I first set up DigitalHam I had recently discovered APRS and the entire focus of the site was devoted to that. I threw in a little PSK31 related info too because as that used computers it seemed to fit in with the digital part of the site name. Next up came the aquisition of a weather station which with a little bodging I was able to use to produce a weather feed through UIView to the worldwide amateur APRSserv network.

Well I still run UIView 24×7 and I’ve fitted my TMD700E into my latest car and fire it up most times I’m driving but my focus has now moved on to polar orbiting weather satellite reception. This is still radio related but doesn’t need a Ham licence or indeed a licence of any sort to pursue – no matter to me it is still a part of amateur radio. Having produced a turnstile for reception I was a little disappointed with the results and the next project was a Quadrifilar Helix or QHA constructed using 8mm microbore tubing from plans found on the web. I suppose once I am happy with the results my attention will move on again but where I currently have no idea.The only real limit to Ham Radio is finding the time and having the imagination. Who knows – maybe next year I’ll finally have set up a decent HF antenna system and actually be able to talk across the world. Maybe I’ll have found the time to use that Morse Tutor I bought on eBay a few years back and return to the ultimate Digital communication system that hams have used since the hobby first began!!The 137MHz homebrew quadrifilar helix or QHA and turnstile pictured on the left was used for APT weather satellite reception. This antenna was damaged during a station move and has been replaced with the third incarnation of my homebrew turnstile design. NOAA satellite signals are received using a R2ZX specialised satellite receiver and the R2ZX audio output signal is fed to a normal PC soundcard from which WXtoIMG software creates the sort of images shown in the weather section of DigitalHam.

Number 1 son M0XDK Corrie has been using his web skills too and is in the process of building a web based display of APRS beacons using Google Mapping and a live APRS-IS feed. The site is currently running on an ADSL line from his home. Take a peek at APRSinfo.com to see how the project is progressing.If you found this site useful please tell your friends.

About Digitalham

DigitalHam is a personal website owned and operated by Mark Griffiths – call G6KIZ.

Originally it started life as a few pages devoted to APRS with the intention of adding more on PSK31. As you can see things have changed and the content has broadened.

Over the years I’ve received plenty of correspondence and now DigitalHam is written using the WordPress blogging software to allow easy public discussion of the content.

Please note that I neither buy nor sell any goods – this is a hobby site and the hosting is partially funded by advertising. I hope you find some of the content interesting and maybe even useful.

Should you wish to just email me rather than add a comment to a page you can use my contact form.

Mark G6KIZ