What to go with for a long run ?....

[Oatmeal]

This is something Ive been looking at for a long time.....
The wire I was using has been burnt up and havent had any luck locating any more of it, so Im going to need to make a total change to my antenna system..

I was using 625ft of wire, which I lost little more than 300ft of it....

So, I need to start from the shack and run someother line up the mountain, Im thinking about just going 300ft back on the mountain this time....found a nice level spot...from where the antenna used to be, to this other spot Ill loose about a 100ft in height..

Ive been looking at the Bury-Flex coax from Davis...

Ive looked at this coax and the LMR 400UF, and theres a 4.5 watt differences between the 2.....

What would you guys suggest going with here ?..

 

[midnight special]

that far i would use ladder line with baluns at each end. far less loss in feed line. 73s midnight special

 

[W5LZ]

I saw a thread very similar to this, I thought it was the same one. That other thread ruled out ladder line because it would have to be suspended in some way, not just laid on the ground. If this is in fact not the same situation then I also would definitely recommend using that ladder line instead of coax cable. There would be much less loss doing it that way.
- 'Doc

 

[Oatmeal]

10-4, does the LL have any loss when it gets wet ?.....

I no this must sound crazy, but I saw this somewhere about the LL that the wireman sells.....never saw anything like this...here is where I saw it Coax Calculator ....I did check this out, it would be used on the 27 mhz, and around 300ft ....


This shows the LL been excellect when its dry and shows alot of loss when it gets wet...

Actually I dont see how the wire can get wet inside unless it has been spliced or something.....

 

[W5LZ]

Do losses with ladder line change when it get's wet? Yes, but not as much as the difference between ladder line and coax of any 'size' or brand. The losses change because there's a change in impedance. It certainly isn't 'perfect' but it isn't -that- bad.
How about cost? Actually, it would probably work out to something close, either way. It takes a different 'technique' to run ladder line than it does coax cable. It isn't all that difficult, but it's certainly different in how you have to support it. And then it depends on what resources you have available (trees??).
Strictly from a 'loss' point of view, ladder line is a very good choice.
- 'Doc

 

[RADIOOMAN]

10-4, does the LL have any loss when it gets wet ?.....

I no this must sound crazy, but I saw this somewhere about the LL that the wireman sells.....never saw anything like this...here is where I saw it Coax Calculator ....I did check this out, it would be used on the 27 mhz, and around 300ft ....


This shows the LL been excellect when its dry and shows alot of loss when it gets wet...

Actually I dont see how the wire can get wet inside unless it has been spliced or something.....

Don't know if this is feasible in your situation, but if it is, you might want to consider this:

http://m0kwr.com/zips/Using Ladder Line.pdf

I would not even try his "untested' idea of putting it underground; Dielectric losses in the soil would take its toll on the signal level.

If not elevated far enough above ground you would also need to twist the line every so far so as to keep the line balanced with the proximity effects of the ground.

But if done properly, a very lo-loss, inexpensive transmission line for that much distance.

Of course, baluns would have to be employed, at least on the antenna end.

You could negate the need for a dedicated balun on the tx end by using a antenna tuner with built-in balun.

 

[Oatmeal]

10-4, well Ive got alot of tress here, and Im right up against the mountain...

So, tell me about this ladder line, how it works, what kind I need to look at, how or what kind of swr I may have with it, how much power will it handle, ect....

Back in the 80s I used to use this Trackwire, it looks like this ladderline u all have mentioned to me....but what I used was looked like 14 or 18ga solid copper that was insulated, and I used to 8" coils of oax on each end of it, in which hung on the trackwire, and going to the antenna and the radio I used 2--24ft pieces of coax whish was called lead wires at the time...and to get the swr down you had to slide the coil, or add to the leads of coax...and then sometimes this wouldnt get the swr low enough...

But today, I run or used to run a transistor amp but hasnt been used since Oct, but I do keep it hooked to power, but dont have any coax hooked to it..

 

[RADIOOMAN]

10-4, well Ive got alot of tress here, and Im right up against the mountain...

So, tell me about this ladder line,

It is a low loss, low cost transmission line

how it works,

That is well documented on the internet in multiple places

what kind I need to look at,

300 ohm will not be suitable for your application.
You will need to make your own or look at what is well constructed

how or what kind of swr I may have with it,

A flat match is achievable.


how much power will it handle, ect....

Several thousand watts


Back in the 80s I used to use this Trackwire, it looks like this ladderline u all have mentioned to me....but what I used was looked like 14 or 18ga solid copper that was insulated, and I used to 8" coils of oax on each end of it, in which hung on the trackwire, and going to the antenna and the radio I used 2--24ft pieces of coax whish was called lead wires at the time...and to get the swr down you had to slide the coil, or add to the leads of coax...and then sometimes this wouldnt get the swr low enough...

It seems as your previous experience will give you a leg up on implementing this type of transmission line.

Did you see my previous post with the link to an article about making your own hi-performance, low loss, low cost balanced transmission line??

 

[RADIOOMAN]

The following is one easy and cheap way to implement parallel transmission line for a 50 ohm antenna and transmitter:

Two paralleled quarter wave sections of 300 ohm tv wire on each end of the 450 ohm long run.

square root (450 x 50) = 150
Easy peasy.
Some form of balun will be desired.
The only loss will be the loss associated with the mismatched 300 ohm quarter wave section; and without doing the math I am gonna say that it can probably be ignored condsidering the lack of loss in the long run of 450 ohm parallel transmision run versus coax will more than make up for it.