Easy external scanner antenna project

Status
Not open for further replies.

radiowave15

Member
Joined
Nov 29, 2011
Messages
91
Here is an easy little project for an external scanner antenna with a few parts from the junk bin. This antenna is fine for somewhat local stations; for distant station scanning a tuned J-Pole or dipole antenna would work much better. And of course, the higher you can get this little guy up the better. I may try putting this antenna way up in a tree sometime and see how it performs. As is my way, here's a little YouTube video of the build.

Easy External Scanner Antenna for Police, Fire, EMS - YouTube

Thanks for taking a look.
 

gewecke

Completely Banned for the Greater Good
Banned
Joined
Jan 29, 2006
Messages
7,473
Location
Illinois
After watching the video, the tree mount rather than up next to a mast would have been the better idea. Attenuation by the mast could be a problem, as well as the splice.
Also to improve the the gain, there are other antennas which might be used.
One last touch, might be to paint the PVC a shade of hunter green if you mount it in a tree. :wink:
Other wise this is a neat idea.


73,
n9zas
 

radiowave15

Member
Joined
Nov 29, 2011
Messages
91
After watching the video, the tree mount rather than up next to a mast would have been the better idea. Attenuation by the mast could be a problem, as well as the splice.
Also to improve the the gain, there are other antennas which might be used.
One last touch, might be to paint the PVC a shade of hunter green if you mount it in a tree. :wink:
Other wise this is a neat idea.


73,
n9zas
All excellent suggestions. Lots of options here to modify this basic design.

Thanks for taking a look.

Dan
N3HNA
 

LtDoc

Member
Joined
Dec 4, 2006
Messages
2,145
Location
Oklahoma
Why the PVC? That rubber duck antenna should be weather proof except for the BNC connector. Cover the connection with tape/heatshrink/whatever to weather proof it. Better yet, why not a few different lengths of wire up the sides of that PVC pipe, one for each band of interest. Connect those wires to the center conductor. Run a length of wire, as long as the longest wire inside that PVC, back down the feed line, or just let it hang loose from the bottom. There's no particular need for a connector at the bottom of that, just run the feed line (coax) through the bottom PVC cap, tie a knot in it to hold it in, seal it if you like. That should definitely work better than the typical rubberduck antenna. There's nothing particularly beneficial about a rubber duck antenna except that it's short.
- 'Doc
 

radiowave15

Member
Joined
Nov 29, 2011
Messages
91
Good suggestions as well. Thanks. The initial idea for the PVC was to be able to tie a rope to it, whip it up a tree and hoist it up high quickly and easily. But, sure, there is no definite need for that rubber duck; coax stripped inside of different lengths would be another option. I am amazed though how well it has been working.

Dan
 

northzone

Member
Premium Subscriber
Joined
Dec 19, 2002
Messages
502
Location
Northern California
It is fun to try different things but that is a very poor antenna. First a "rubber-duck" antenna has about 16db of loss at VHF, very poor. Next you have no groundplane. Then loss in splice.

A much better simple antenna is to take a female "UHF" connector (SO-239) turn it upside down and solder a vertical element to the center pin and 4 radials to the ground part. They work great.
 
Status
Not open for further replies.
Top