Well hello, maybe your reading my blog on amateur radio – I had a very nice weekend off and relaxing/downtime getting things done, but with that there was ALOT be done with regard to Amateur Radio !
Where do I start… well, lets first say thanks to my good friend and fellow radio amateur Trevor (PA2TG) who has been absolutely amazing in offering me advice on what I’m about to talk about ! So here we go !
So I have got (two) new masts, willl talk about the other in another posting one day, but lets focus on the the fibreglass 40ft one for now.
I took some careful time rigging, i used the lightweight rigging but I really didnt want to start with. This looked good, and I got the mast upto full height. The problem then become apparant that my coax was now too short ! At 30m in length, at the time that seemed long enough as i was using my buddipole then and the coax was purely for experimental purposes.
The 40ft mast, is amazing, i will give it its own posting, in this post I want to concentrate on the coax I made for the mast as I’ve got some great advice, with more understanding about coax and loss that I could of ever asked for thanks to Trevor. I will point out that I ordered and received the coax a while ago, before speaking to Trevor, but I now know what to order next time, and it will make me appreciate what I have and how much power is being lost in the coax itself (you would think not much, but suprsingly, even the top quality coax, has some loss!)
So the Coax I had is https://www.radioworld.co.uk/rg-8-mini-coax-cable-50-ohm-military-spec-50-metre-drum – I really dont undertand all the specifications, and the price is right. I soon learned from Trevor not everything is what it seems and also websites on coax/loss confirmed what he had told me http://m0taz.co.uk/2017/11/coax-cables-and-associated-losses/ This cable is RG8, so of my 10 Watts going up the cable, on 2m 3.5w will reach the base of the antenna, so getting 1:1 S.W.R. is really important ! (3.5w !!?!LOL!>!!!)
So I set about making my cable with the coax, I found this video most useful https://www.youtube.com/watch?v=GjO5ERU6a78 and following it found that I had created an awsome cable. Now if I was honest, that would be the end of it, but I have to admit I made rather hilarious mistake… In the video he does a continuity test, to ensure the cable is shielded and the center pin will deliver the RF power/energy.. I thought, well, why not strip the other end and check from both ends ! Great idea M7ALU ! So I stripped the other end.. measured continuity, come on 0… 1… a solid 1, not any reduction.. traces cable.. i’ve stripped the cable from the reel… So, when stripping cable, make sure you get the right one.
In the end I stripped. sheathed and plugged my cable in with loads of testing for continiuity, because I dont want to get it 40ft+ up and find its not working. Results soon.
Tomorrow she goes up, lets hope 1) I got the length right 2) it keeps working 3) The cable is good enough spec for me on 2m/70cm and 10 Watts of power.. We shall see !