Antennas

[greeneyes965]

I just wondered how would i hear the police if its 50 miles away what kind of antenna do i need

 

[davidmc36]

I just wondered how would i hear the police if its 50 miles away what kind of antenna do i need

The "kind" of antenna would depend on what frequency range.

If you check here: http://www.qsl.net/kd4sai/distance.html you can do some calculations about how high you will need to get your antenna. This is all theoretical calculations for VHF/UHF which needs "line of sight" over the horizon. You can get some signal if it is over the horizon or a few small hills but in most cases very little and it will be of poor quality.

What is your location? What system are you listening to? Is it in the database?

The calculator says you will need each antenna over 300 feet in the air to get 50 miles over the horizon.

 

[Don_Burke]

I just wondered how would i hear the police if its 50 miles away what kind of antenna do i need

You also need to consider what kind of system you are listening to.

A repeater system with an antenna at 200 feet is going to require a different solution than a mobile-to-mobile system.

 

[radiopro52]

It's possible, if it's VHF. I can pick up a police station over 60 miles away that is VHF. But if it's UHF, 50 miles is quite a long distance, but still possible if the station outputs enough power and you have a good antenna setup. But it would still be weak at best. For best results, you could use a directional antenna pointed at where the signal is coming from.

 

[R1VINCE]

I googled your location and looked at the terrain.

This antenna ----> http://www.radioshack.com/product/index.jsp?productId=2103641
is fairly cheap and will allow you to hear well within the 50m that your seeking, assuming that you are mounting on the roof and that you have no obstructions. And use good coax

 

[skydmark1]

I can pull in the VT state police Troop B signal from Derby, VT and I'm in Littleton, NH. It's probably a solid 40-45 miles as the crow flies. I pull that signal in on my Uniden Sportcat handheld with a rubber duck antenna!!!!

For my use, I'm figuring that I can pull in within a 35 mile radius with a discone antenna mounted on my roof.

 

[zz0468]

Be aware that in some systems, great pains are taken at the engineering level to PREVENT them from being heard outside their primary service area. If you're listening to a system that has to deal with co-channel or adjacent channel systems elsewhere, there may not be much you can do. Try a simple antenna up high. If you can hear it at all, THEN you can consider investing in something with more gain.