Re: Best coax to use?
When I built my tower and beam my DX Elmer told me the coax I would buy would not be the last I would install. He was right.
I got some cheap stuff from a trunk sale at a hamfest. It was the diameter of RG-8 and I liked it. But it started having problems. For example I could not pump any power down the wire. I'm replacing it.
The replacement will be LMR-400. I'll run it to both the HF beam and to the two-meter vertical. My tower is 150' from the shack. I know, the loss of RG8X isn't too bad on HF. I just don't need to take the chance.
I wouldn't run any coax longer than than I need to. But, for a G5RV you need at least seventy-five feet of coax. It's part of the antenna system. Otherwise keep the length to a minimum. All things being equal, you will have fewer problems.
And take the time to waterproof all the joints. All of them. Even the ones inside a pull box or conduit. It's cheap insurance.
And you can coil up enough coax to allow the rotator to rotate. Just wire tie it to the top of the tower and to the mast supporting the antenna. Add a little extra and you're good.
Unrelated, I have grounded the tower. There is a whole other world of RF and lightning grounding. Ask around. It is something you can add later. I was making so many trips to the local Rag and Metal recycle guy that he finally said, "OK, when I get a ground rod or two I'll just drop them off at your house." He had a good price on copper, too.
Hope this helps.
--- In WestMichiganHams@yahoogroups.com, "wallymsu" <wolthui3@...> wrote:
> I am in the process of installing a new tower and an HF beam setup. Having never done this before, what is the recommended coax to use that will work will with the rotor? Rotor is capable of 480degs so any suggestions would be great for coax.
> I also plan to put an omni at the top, so that will also need coax that can rotate some. Is the preferred method to make loops to take stress off and zip tie that to the tower and then leave enough for the full rotation?
> I need to get coax ordered this week.
> Also, is there a recommended length? I remember hearing something like 75ft to the lightning protection and then extend it to the radio.
> Want to get this right the first try. Also, where you would buy the coax would be great, ie. Cable Experts etc....
> Thanks for any suggestions,
- On waterproofing coax connections, I offer a link. Look through the newsletter to find Technical Topics.
You might have to be a member of the ARRL to access the link? I'm not sure as it isn't an issue with me.