A long run to the antenna ?......

[Oatmeal]

Hello guys, as some of you guys know I had a forrest fire here a month or so ago and it burnt up alot of the wire I had ran up to the ridge and feed my antenna, well I dont have the wire to fix this....

So, Im looking for something to replace the wire I was using, and Im looking for something to get the job done, or if it works better than what I was using..
The wire I was using, only thing I didnt like about it was, when something heavy stepped on it, the wire always had a bent place the wire, and that was always a problem that had to be fixed....but the stuff I was using has been up there for 3 years...

So, is there anything out there that works as good or better ?.....

What do you guys use for a long run to your antennas ?...thanks..

 

[vo1ks]

For an overhead run, openwire or ladderline has the lowest loss and highest power handling capacity.

 

[Oatmeal]

10-4, which ladderline would I need to use, ohms, ect ?.....

How would I connect the coax to the ends of the ladder line, just splice it in ?..
This will be used on the 10 and 11m bands, by the way...forgot to mention this from the start..

 

[fodendaf]

you'll need a current balun to convert from 50 ohm unbalanced from the radio to balanced ladder line. if u use a 4 to 1 balun then u use 200 ohm ladder line but the ohms of the ladderline is not critical as it is not lossy like coax if you have a mismatch and you use an atu to bring the swr down.if u use a 1 to 1 balun then use 50ohm ladderline. i don't know do you need a balun at the antenna end, i say not with a 1/4 wave vertical as it is electrically similar to a doublet, maybe 1/2 wave endfed a99 might be different. you'll find out straight away if you can't get the swr down to tune up.

 

[W5LZ]

Ladder line, or parallel feed lines do tend to have less loss than coax and a higher power handling ability, but they also have their own set of 'qwerks' that you have to deal with. Probably the most common difference is that you can't lay it on the ground, or have it 'near' things without it being affected. Not impossible, just different ways of doing things. The most commonly found is probably 450 ohm 'window' line.
If the antenna and transmitter are 50 ohms then you have the requirement of matching impedances to that 450 ohms at both ends. Probably the most common way of doing that is with a 9:1 balun. But then, it you plan on using that one antenna on several bands, that 9:1 ratio is out the window, forget it, it won't be the right 'size' for different bands. It get's to be fun after a while.
And probably the 'easiest'/most common method of using ladder line is to forget about the antenna to feed line SWR, just do the impedance matching at the transmitter end with a tuner. No, it isn't the 'best' way of doing it, but neither is using that one antenna on several bands. It works. In most cases it works just fine, but not in all cases. It also means that you'd better know how to use that tuner, it won't stay the same all the time. that's another one of those 'qwerks' about parallel feed lines, water/rain/snow can and does affect it. Why a fairly 'broad' tuner is really nice, cuz it'll handle those changes... mostly.
I like using ladder line, as if you couldn't tell...
- 'Doc

 

[vo1ks]

Almost anyone I've seen using open wire feeder has used an antenna tuner. However with proper techniques I'm sure you could connect it to a coaxial cable via a proper balun and have an acceptable swr.

You can purchase plastic coated 450 ohm ladder line from many radio supply stores.

I've also seen dual runs of coaxial cable used as a balanced feed line. Tie the shield together at both ends and it can be buried, taped to a tower, etc. The line impedance is 2x the characteristic impedance of either coaxial cable.

10-4, which ladderline would I need to use, ohms, ect ?.....

How would I connect the coax to the ends of the ladder line, just splice it in ?..
This will be used on the 10 and 11m bands, by the way...forgot to mention this from the start..

 

[Brake Weight]

There is a recent thread about 75 ohm rg6 for long runs.

 

[The DB]

If you choose to use a balanced feed line be sure to note that it is not like coax. If you are going to use it on multiple bands you need an antenna tuner before the balun. In this setup the impedance of the balanced feed line isn't critical. I would use more of a ladder line than a window line for your run, and you can easily make some in your garage without to much of an expense. 14 ga wire, a few large packages of cheap ball point pens, zip ties, and something to cut the pen tubes with (optional). You do not run it along metal, although you can cross metal. You do not lay it on the ground or bury it under the ground or the main low loss benefit will be lost. PVC works well for standoffs as does plastics.

You were running an imax 2000 if I remember. If you are using with multiple bands and you would normally feed an antenna directly. You wouldn't need a matching network like the one built into the imax, as well as most commercial base cb antenna, but it should still work. You would directly connect the feed line to the input on the antenna in the case.

This setup would be more versatile than just 10 and 11 meters.

You could use baluns on each side as well as a known impedance on balanced feed line if you are going to use the antenna within its natural bandwidth. This would also work if the antenna you were using already covers all of the frequencies you are planning on transmitting from within its bandwidth. Should you ever decide to get a ham radio license of general or better on any of the HF bands, the antenna tuner into a balun with feed line directly fed to the antenna will give you far more frequency availability.


The DB