Antenna help

[Huntingdeer24]

Ok so I got a tram antenna with a 2 way radio the police did use at one time.Im not sure if the antenna is for 2 meters.Im a new ham and wondering if this antenna will get the job done on a mag mount.I resold the radio I'm not using it just the antenna. Any help?

 

[mmckenna]

If it came with a radio that was used by the police, it's likely resonate somewhere above 154MHz or so. So, it would be too short for 2 meter use.

You can purchase new, uncut whip for them, and cut it the correct length for the 2 meter band.

If you could measure from the bottom base of the spring to the top of the whip, we could give you a general idea what it is tuned for.

Quarter wave antennas are inexpensive, so while purchasing a new whip would be a good option, you can purchase a brand new antenna (base and all) for less than $15.00

 

[Huntingdeer24]

It measures 16 and a half.it does have a tuning screw.so just junk it?

 

[Huntingdeer24]

I may of misread the question.its 15 1/2 inches from tip to bottom of spring base.

 

[mmckenna]

You can try loosening the set screw and see how much longer you can make the antenna. For 2 meter amateur frequencies, you need something around 19 inches.
It's unlikely there is 2 1/2 inches in there.

You could use it as a scanner antenna. Should work well for VHF and UHF monitoring.

As stated, you could find a replacement whip and trim it to somewhere around 146MHz for use on 2 meters.

Or, just save it for parts. I wouldn't junk it, you never know when you might want it for a project. The NMO base and spring are still useable.

Other option would be to trim it for use on the 70cm amateur band.

But seriously, you can get a basic 1/4 wave VHF antenna for the 2 meter band for $9.95 at http://www.theantennafarm.com/catalog/laird-technologies-qw144-718.html

A replacement whip is going to run you about $7.00, not sure if this is the right whip diameter, though:
http://www.theantennafarm.com/catalog/larsen-w200-7615.html

 

[Huntingdeer24]

Well see I got one off eBay a few weeks ago with rg174 cable and 1/4 wave I just feel like its junk.the reception is not to good.its a short antenna.

 

[Huntingdeer24]

10 inches is what the one I'm using now measures.

 

[mmckenna]

Sounds like a dual band "center loaded" design. There is likely a bulge in the center, or maybe the bottom, that "electrically" makes up for the shortened length.