Antenna Help

[joesheets]

Hello,
I'm in the process of setting up a VERY simple long wire antenna. I have 2 lengths of 18g insulated wire, each about 50' long. I have stretched one of the lengths out a windo to a tree about 30-40' up. I have an additional 70' to the radio through the attic. I am either going to connect RG8 coax to the outside wire and terminate with a 1/8 plug to the radio (Grundig G5). Or I could connect another 50' length of wire to the outside wire and then connect the coax at that point. My questions are:
1) Is there a negative consequence to having close to 75-80' of coax from the long wire to the radio?
2) Is there an advantage to having another 50' section of wire inside the attic?
3) What is the best set-up?
Tahnks,
Joe

 

[k9rzz]

1) Is there a negative consequence to having close to 75-80' of coax from the long wire to the radio?

You won't notice any interaction between the wire and the coax.

2) Is there an advantage to having another 50' section of wire inside the attic?

The longer wire will give you better result on the lower frequencies which are the important ones at this time of the solar cycle. Basicly: The longer - the better.

3) What is the best set-up?
Tahnks,
Joe

To keep it simple: forget the coax and just run wire. If you have a lot of interference from your computer or other noises in the house, then think about running coax to the outside. If you can live with out the coax (and you very well might) then that's your solution!

 

[kb2vxa]

1) Yes, unless the transmission line is decoupled properly it becomes part of the antenna so it becomes useless as a transmission line and may pick up noise.

2) Only that it lowers the resonant frequency enabling it to pick up lower frequencies better.

3A) Use a 9:1 un-un usually incorrectly referred to as a "long wire balun" to connect the coax to the antenna and ground the shield. Please refer to answer #1.
3B) Just run wire all the way and forget the coax.

To sum it up, stop asking what is "best" simply because there is no answer to such a question. Only YOU can answer that question by experimenting and finding out what works for you. What's good for the goose is NOT what's good for the gander; every installation is different, what works for one may be another one's disaster. In other words take note of 3A and 3B, try them both. Where and how you run the wire changes everything, if it's not satisfactory one way try another. Keep it as far from metal objects and other wiring as possible to keep noise and spurious signal pickup to a minimum. Where and how you run the coax shouldn't matter BUT the key word is "shouldn't" being that nothing is perfect, it CAN pick up noise and spurious signals for various reasons a bit too technical for practical discussion here. In a word, experiment.

 

[k9rzz]

In a word, experiment.

Well put. Bravo!

That's half the fun of radio and a great way to learn!

 

[joesheets]

Thanks, All for your responses. I will start the experiments today. I keep you posted!
JS

 

[kb2vxa]

Uh oh, if we don't hear any more from you we will know what happened.

 

[N_Jay]

ARRLWeb: ARRL Product Catalog

Reading and experimentation go hand in hand.

Read what should work,
try it and find out it doesn't,
read to find out what you did right and wrong,
make purposeful improvements,
find out they helped, (or didn't),
Read more about why,
LEARN

Or do an experiment,
Find out it kind of worked,
make some unplanned changes,
find out it "seems" better (or worse),
Make a few more changes,
takes some subjective measurements,
build a "theory" as to what works and what does not.
move forward with "theories" and "Myths".

The choice is yours.