Basically it’s a race. The first station to gate your packet suppresses any others that might be hearing you.
4 Likes
Ben, it is easier now that Richard has a Web based interface for the iGate.
But He is still using VSC and PlatformIO, for the tracker.
I Think we will be okay, "but if I do it you will have no problem. "
My T-Beam is arriving tomorrow morning by Postie. hopefully our iGates will help each other when we out and about?
73 Tony
3 Likes
I always have a list of things to solve on firmwares, but I hope to start this week (finally) with the base of the change to WebInstaller also for tracker 
6 Likes
What’s equally impressive is that there is a hell of of a lot of rock in the way as well (i.e. the Carneddau).
Dave
4 Likes
That would be superb for us mere mortals, I have tried teaching myself Linux, but my brain is not superior enough!
Thanks for all you have done to date best 73 Tony
2 Likes
The amount of rock in the way is impressive. Anyone have the ability to plot the rough terrain between the two points?
1 Like
Knife edge diffraction over Snowdonia. Back in the early 80s (82-ish) there was an article in RadCom about how it was possible to stand on the promenade at West Kirby, Wirral (not too far from M0VAZ’s QTH) and work the GB3AR repeater over a very obscured path. I think the repeater now has a new home, it may have been on a TV TX mast then. (You know when companies provided services for peppercorn rents to community groups like hams!)
4 Likes
When TV masts were owned by public corporations such as the BBC and IBA.
3 Likes
2 Likes
Just plotted the same 
The article is:
“The Snowdon Effect - an interesting case of VHF propagation” by J. David Last, PhD, MIEE, GW3MZY
RadCom Feb 1983 pp 136-138
3 Likes
I was in a boring meeting John… Interesting the path just misses Carnedd Llewelyn and the Ogwyn Valley. So as Andy says, there must be a bit of Cliff Edge scatter going on to get over 750m.
Dave
2 Likes
Thanks Dave. I was also in a bit of a bored moment replacing SSL certificates.
I was impressed when I saw the location of the tracker and then terrain that was covered.
John
3 Likes
Is this available to non-Radcom subsribers?
I wouldn’t bother with (probably) dodgy articles in Radcom. Source such as https://www.itu.int/dms_pubrec/itu-r/rec/p/R-REC-P.526-5-199708-S!!PDF-E.pdf cover the topic. If you fancy an early text, I always found the paper by Jacques Deygout to be useful.
Multiple knife-edge diffraction of microwaves
J. Deygout United States Department of the Army
01 Jul 1966 -
IEEE Transactions on Antennas and Propag…
(IEEE)
- Vol. 14, Iss: 4, pp 480-489
2 Likes
Thanks.
I think you’re being disingenuous Richard if you haven’t read it especially as it references IEE, IEEE and Bell System Tech Journal articles. It’s from when RadCom contained relatively learned articles and not the lightweight material the fills many pages today.
1 Like
I would have thought nowadays the bulk of bodies on top of Snowdon would absorb the RF !
I have had the same effect sometimes from Hereford to the other side of the Malverns ridge
Rick
3 Likes
I haven’t read the article. Unfortunately quality references don’t always mean that an article is good. The Daily Mail often references perfectly good sources but manages to get the details completely wrong. I will take your word for it that it’s a good article.
1 Like