Firstly thank you Alex for all the time you dedicate to making FPV an even more interactive experience for alot of us. I love the fact that i know nothing about RF yet can make a set of antennas that can potentially give me video 5 - 10 even 20 kms away. All from a few dollars of raw materials.
Now, to pick your brain (and please, anyone else is welcome to chime in if they know what i need)
1) What is a good 5.8Ghz vrx antenna to go alongside a SPW in a diversity set up? I wont be flying beyond 2.5km (only using FrSky RC) and would like to be able to fly amongst some obstacles / trees / etc. Wide beam angle would be a big plus too but not sure if i'm asking for too much
2) I have built a set of CL / SPW's and while they gave good results they were a bit messy and i would like to try again so have a few questions regarding fine tuning.
As i understand the length of the arms on the lobes need to be trimmed to allow for the width of the the insulator (on the lower arms) and the feed gap (on the upper angled arms) but i am not 100% sure on which point i am trying to gauge my 1/4 wavelength from.
a) Does the lower arm (horizontal) need to be 13.233mm (1/4 wavelength) from the centre of the signal wire to the centre of the wire at the bend?
b) Does the angled arm need to be cut to measure 1/4 wavelength from the centre of the lower intersection (on the same plane that the lower arms meet) or centre of the upper intersection (on the same plane that the upper / angles arms meet) (as marked in the below drawing)
3) What can i use to get the solder to stick to the copper coated mig wire. I am using .6mm wire and 60 / 40 lead tin rosin core solder. Flux kind of helped but it was still very difficult to get a good clean join.
Thanks for any advise.