Copper wire antenna

[voxiso]

I got about 2 foot of copper wire and it fits perfectly in the scanner (396XT) I am having issues monitoring my local state police post which uses P25 conv the closest tower is 19 miles away, I can hear maybe 30% of each transmission and sometimes just one side of it but what does come in is clear.. I put this copper wire in the scanner and it did not show any improvement over the stock antenna the freq range is 453-460.. Does the wire need to be cut to a specific length for that range or does that matter?

Thanks.

 

[Ed_Seedhouse]

I got about 2 foot of copper wire and it fits perfectly in the scanner (396XT) I am having issues monitoring my local state police post which uses P25 conv the closest tower is 19 miles away, I can hear maybe 30% of each transmission and sometimes just one side of it but what does come in is clear.. I put this copper wire in the scanner and it did not show any improvement over the stock antenna the freq range is 453-460.. Does the wire need to be cut to a specific length for that range or does that matter?

Two feet is a bit long for best performance on the usual VHF frequencies used by safety agencies and the like. It is way too long for UHF frequencies that are more and more in use. But what matters more is location. A more sensitive antenna won't help you if it just picks up local noise more efficiently.

You will do better with a piece of coax that you can use to put the standard antenna up higher and away from local noise. If you can get twenty feet or so of coax and put the antenna outside that will help even more. TV type RG6 will work fine, even though it's not technically correct, but you'll need adapters to connect from F to BNC type connectors at each end.

I use a dual band ham antenna out on the lawn at the end of 50 feet of RG8 coax and it does wonders. It's mainly there as a transmitter antenna for my Ham band handheld radio, but plug it into the scanner and I get excellent results. You might not have the room for that but the general rule is first to get your antenna up as high and as far away from your house as you can given your restraints. Then get a better antenna if your results are still poor.

A better antenna is not always the solution, however, especially if all it does is amplify strong local signals to the point where they overload your scanner's front end.

 

[LtDoc]

Does the antenna (wire) have to be any particular length? Quick-n-dirty answer, yes it does. It helps if an antenna is a resonant length for the frequency/range you want to hear. If you are only listening then that particular length doesn't have to be exact by any means.
The other thing, especially with VHF/UHF antennas is the antenna's height. To an absolutely ridiculous point, higher is better.
There's nothing 'magic' about copper in any form when used as an antenna. Whatever metal used, if it will conduct electricity it can be an antenna.
- 'Doc

 

[k9rzz]

I think you'll do better by finding a sweet spot for the best signal. 19 miles for 460mhz is pretty much fringe coverage for a 396XT. THey aren't out to maximize their distance, only saturate their own area with signal.

 

[Ed_Seedhouse]

Does the antenna (wire) have to be any particular length? Quick-n-dirty answer, yes it does. It helps if an antenna is a resonant length for the frequency/range you want to hear. If you are only listening then that particular length doesn't have to be exact by any means.

This is perfectly true if you are transmitting on the antenna, but much less true for reception. Most any modern receiver will get enough power from a mismatched antenna to provide all the signals that are sufficiently above the noise level. Length of the wire will affect reception patterns, but hardly affect the reception abilities of a receiver.

The most important thing is to reduce the noise level on reception, and we do that by getting the antenna away from noise sources so that the signals become receivable. For VHF/UHF which are largely line of site we also want to be as high as we can. If the transmitter can't "see" you you are unlikely to receive it's signal unless it's really pumping out the juice or bouncing off something that both of you can "see".

There's nothing 'magic' about copper in any form when used as an antenna. Whatever metal used, if it will conduct electricity it can be an antenna.

Agreed.

 

[LtDoc]

"...perfectly true if you are transmitting on the antenna, but much less true for reception."
Right, and that was covered in my post.
- 'Doc