Char / Meck Police car antennas

[jplyler]

This might be a dumb question but I really don't know the answer. I've noticed many of the CMPD and North Meck units have 1/4 wave VHF-Hi antennas. What are these antennas used for?

Jon
N4ZVY

 

[gmt0000]

More than likley, it is the receiver for the wireless mic associated with the dashboard camera system in the car. The officer wears this mic so that the video will have the officer's audio. Typically, these wireless mics used with camera systems operate in the 169-172 MHz range, and don't require a license.

gmt0000

 

[Bill28227]

More than likley, it is the receiver for the wireless mic associated with the dashboard camera system in the car. The officer wears this mic so that the video will have the officer's audio. Typically, these wireless mics used with camera systems operate in the 169-172 MHz range, and don't require a license.
gmt0000

gmt0000 is correct. These are for the wireless mics that the officers wear. I have heard them in the 169 and 170 MHz range for a matter of 100-200 feet. The cameras can be turned on manually in the car, or automatically by turning on the blue lights, or by a slide switch on the mic case that the officer wears. If the camera is recording there is a little yellow light that comes on inside the car front grill. Beginning late this year and for the next five years they will be converting to a digital camera system in all the cars. I don't know what this will do to the analog voice system they use now.

 

[jplyler]

I would have never guessed that but it makes since. Any idea what freqs they use. Knowing it's VHF-Hi it wouldn't be too hard to find. I'll have to do a little searching next time I'm around one of them. Do they switch their mikes manually or are they on all the time. I'm guessing the former.

Jon
N4ZVY

 

[khubbard]

try 169.445 or 170.245

 

[tglendye]

wow... never thought about trying this.

 

[Grog]

Beginning late this year and for the next five years they will be converting to a digital camera system in all the cars. I don't know what this will do to the analog voice system they use now.

Sounds like two different things. If they are using analog video systems (tapes), and they are going to digital (download to a computer), then the microphone system does not have to change at all.

 

[CFDtracker]

When they change systems, the mic frequencies will change too.
The mic system is a part of the actual video recording system.

The digital system is supposed to use a 900 MHz mic, and the receiving antenna is mounted on the charging cradle for the mic which is installed in the car. So they will no longer need an external antenna on the car. The company that sells the recording systems claim they work up to 1000 feet (no typo one-thousand). The transmission is also digital.

Some of the newer VHS systems are already using this digital 900 MHz mic.

As far as the older VHS systems go, the 170 MHz mics are digital encoded, and again are said to work for 1000 feet.