Newbie question

[wwelles]

I'm wanting to get the cheapest starter antenna going. I've been researching and thinking a "Long Wire (Random)" is what I need.

I have a 20-30 ft length of coaxial cable to work with (one end stripped like far right in imagine below, one end with the F Connector still on).

Looking for advice and what needs to be done to get a basic setup going. Can it be connected as is? I realize it may not be able to receive clear signals from the moon, just looking for something basic to get started.

Receiver for reference is a Realistic DX-200.

 

[majoco]

The pic has gone. The cable won't be an antenna, just a feeder screened to keep out the noise from your house. You'll need 60feet or more of stranded insulated wire joined to the centre conductor of the coax cable and run it away from the house and as high as you can get it. Tie it to a tree or something but allow some slack for the tree to move in the wind.

That'll do for a start, but be prepared to modify it at any time - that's half the fun!

 

[wwelles]

The pic has gone. The cable won't be an antenna, just a feeder screened to keep out the noise from your house. You'll need 60feet or more of stranded insulated wire joined to the centre conductor of the coax cable and run it away from the house and as high as you can get it. Tie it to a tree or something but allow some slack for the tree to move in the wind.

That'll do for a start, but be prepared to modify it at any time - that's half the fun!

Would the coax work if the shielding is removed on both ends? If not, would exposing an entire section of inner core work?

 

[wwelles]

The pic has gone.

Similar image, I've removed A and B from one end:

 

[majoco]

If you don't have the screen connected at the receiver end, then it's not a screen.

If you just leave one inch of the centre sticking out, then you have an antenna one inch long - not a lot of good. Connect your 60ft longwire to the centre - now that's an antenna.

 

[wwelles]

If you don't have the screen connected at the receiver end, then it's not a screen.

If you just leave one inch of the centre sticking out, then you have an antenna one inch long - not a lot of good. Connect your 60ft longwire to the centre - now that's an antenna.

I think I wasn't clear that the shielding worked if it was stripped back at the ends. Sounds like I'd need to strip the amount to match the antenna length desired.

Thanks for the help!

 

[LtDoc]

One alternative to 'stripping' that coax is to just connect the shield/braid to the center conductor. That makes the whole thing just a plain old 'wire'. Connect that shorted coax to the center pin of your antenna jack and all of it will be the antenna. That would work for just listening. For making it a transmitting antenna it won't work worth a hoot.
Something to think about is that a resonant antenna tends to work better than a non0resonant one. Resonance is dependent on the frequency of use and the length of the antenna. Expecially for the lower frequencies, longer is better. For any frequency, but especially for VHF/UHF stuff, high is more better.
All of the above is a 'ball-park' generalization, not close to being 'exact' by any means. The best sort of antenna for any particular location/situation is the 'best' that you can manage. Then it's just a matter of 'tweaking' things (make changes) till it doesn't 'help' anymore.
Have fun.
- 'Doc

 

[wwelles]

One alternative to 'stripping' that coax is to just connect the shield/braid to the center conductor. That makes the whole thing just a plain old 'wire'. Connect that shorted coax to the center pin of your antenna jack and all of it will be the antenna. That would work for just listening. For making it a transmitting antenna it won't work worth a hoot.
Something to think about is that a resonant antenna tends to work better than a non0resonant one. Resonance is dependent on the frequency of use and the length of the antenna. Expecially for the lower frequencies, longer is better. For any frequency, but especially for VHF/UHF stuff, high is more better.
All of the above is a 'ball-park' generalization, not close to being 'exact' by any means. The best sort of antenna for any particular location/situation is the 'best' that you can manage. Then it's just a matter of 'tweaking' things (make changes) till it doesn't 'help' anymore.
Have fun.
- 'Doc

Ok, that makes sense. One further question: Does anything need to be done to the end of the wire with the F Connector? Can it stay the same, or do I need to strip the end there and just use the core (centre) in my antenna jack? I guess what's I'm trying to ask is: Does the F Connector ground or negate shorting the other end?

I understand this is just to receive, and that higher is better, but just looking to get started as you said.

Further, I found a few articles below which suggest random wire lengths to fill a broad range of frequencies, is there merit to these? Would my random wire length essentially be doubled by shorting the end, or would it remain the physical length?

http://www.hamuniverse.com/randomwireantennalengths.html
http://udel.edu/~mm/ham/randomWire/

Thanks!

 

[LtDoc]

Is there some reason why you want to keep that 'F' connector, as in does it fit the connection on your receiver? If it isn't a 'fit' for your receiver's input jack then you could cut it off with no particular problem. If it does 'go' to something and you don't want to loose that ability to use it, I wouldn't use that coax at all.
The basic idea is to turn that coax into a single conductor by shorting the braid and center conductor -AT- the receiver end of it. Won't matter what's done to the other end, it's effectively a single conductor if shorted at the receiver's end. How about shorting out the 'far' end and swapping the thing around, put that 'F' connector at the 'far' end. If you do that, and if you want to be able to use that coax on whatever you took it off of, weather proof that 'F' connector.
If you don't short the receiver end of it but do short the 'far' end of it, no, it doesn't turn it into 'double' the thing's length. It -will- be like just shorting the receiver's antenna input, not exactly something you want to do.
I'm not sure I said that very understandably...
- 'Doc