Hi,
Thanks to all for the info.
I made my 1/4 wave spider GP antenna and made the element lengths 67 mm, I used 4 legs, I read some use 6 or 8 legs, does that make much of a difference ?
I disconnected my 2 meter band antenna and connected my ADS-B spider antenna to the end of the 7 meter run of LMR 400 coax to my loft.
I left it running over night, and checked it the next day.
I was quite impressed with the loft antenna, as opposed to it just sitting on the window sill.
Checking the Polar diagram, I am receiving a lot farther out, as expected, and fairly uniform in all directions, at least out to about 100 plus miles before it starts breaking up in places.
Im not quite reaching all of the propagation rings, but am reaching them in a few areas.
I can see a little null to the South, which I think is my chimney pot ?
It is interesting sitting watching the distance and seeing how far I am receiving aircraft from, the best I have had is 192 miles, but the aircraft was at approx 39,000 feet or so.
I did get a Ryan Air showing that it was 5624 miles away, over the Indian Ocean, and it even plotted its position over the Indian Ocean on the map.
The Ryan Air was an Edinburgh to Spain flight, so I guessed it was just a glitch ? but in a week of using the Radarbox, that was the first "funny" that I have seen.
Im happy with it in the loft, but am now intrigued as to what reception will be like with an outdoors antenna.
I found my self hanging out the attic window tonight, before it got dark, measuring up for a little bracket, so that will be my next move.
Steven.