base coax

For a base station, I would recommend using RG-8/U. It has half the loss of RG-8/X, and a third the loss of RG-58. You will probably pay about a buck a foot for it.

Above all, be sure that you are using a name brand cable. I'd buy from the ham radio stores over the CB shops; CB shops have a tendency to buy the cheapest stuff they can find from what I've seen.

www.hamradio.com
www.aesham.com
http://www.dxengineering.com/parts/dxe-8udu050/overview/ (free shipping)
http://www.universal-radio.com/catalog/cable/cable.html (RG-8X)

 

Farmer,
I wholeheartedly agree. Because your feedline is so long, you really do want to minimize the amount of loss your signal has to endure in both directions.
Also, be sure to tie wrap (or tape) the coax to the mast every couple of feet so that none of the weight of the coax is hanging on itself or on its connector. Leave a little slack, or a "sideways S-curve", from the topmost tiepoint to the connector on the antenna, so that you've got room to fit a wattmeter inbetween the coax and the antenna connector if you ever have to check things. (You'll probably want to test this whole thing before you stand it up all the way, anyhow, just in case there's something wrong -- easier to fix 4 feet above the ground than 60 )

Put a small drop of silicone grease on outer threads of the base antenna's connector; it'll help keep moisture from migrating into the connector and will keep the PL-259's shell from seizing from corrosion. And wrap the outside of the connection with Coax Seal or Scotch 70 or silicone tape ( www.coaxwrap.com ) to make a waterproof covering that can be opened back up if you ever want to check things or re-do the connection.

Since you said you're using a wire dipole, remember that the feedline should depart from the feedpoint at a right angle for some distance (ideally at least a quarter wavelength) so that it doesn't interact with one leg of the dipole. It's not usually a problem if the dipole is horizontal, but if it's a vertical dipole, you'll want to find some way to hold the coax up so it's horizontal for a ways. This might mean having to have a 9-foot standoff from the top of your antenna support from which to hang the dipole, and another standoff at the bottom end to hold it taut.
Also consider building an "Ugly Balun" (actually an air choke) since you're going to have a very long unbalanced feedline (coax) going to a balanced antenna (dipole), you'll have a very long "unintentional radiator" (the shield of the coax) available to transmit RF from along its length.

If your base rig is right next to a window and you can support the feedline without having to have it bound tightly to the side of a building or tower, there is a way to use a balanced feedline like ladder line, have virtually zero loss and very low cost, but it has to be able to be kept pretty much in free space (a foot or two from any substantial mass) all the way to the antenna. I use balanced feeders for my 360-ft skywire loop here at the house, about 60 feet up in the trees, but it's anything *but* plug-and-play, and I have to use one or another of a couple of tuners depending upon the band.

Just one other source I'd add to MsJamie's excellent list of resources is www.thewireman.com

They're in South Carolina, and sell all manner of coaxes, Coppperweld and stranded wires, lightning arrestors, switches, insulators, etc. They're got a pretty good coax comparison chart.

Sorry for the wordy answer; I just realized most of it isn't related to your question.
73,
Handlebar

 

For base coax, IMO you can't much better than LMR-400.

 

Sure you can.... LDF7RK-50A. Kind of overkill but?????

 

Any time you add an adapter in line you will also add loss but if that's what it takes to get on the air go for it.

 

I use andrews ldf 7/8's foam, but I'm sure RG213u would be fine. I just had the Heliax left over from a job.

 

If you need to splice, then splice. I'd recommend using compression type BNC connectors for RG8X. In fact, that's the only thing I put on that size cable. A properly installed BNC + PL-259 adapter has far less loss than an improperly installed PL-259.

A lot of people think they know how to properly install a PL-259 connector. Most of them don't.

 

So how about posting us a youtube video on how it ought to be done.............................