2 part question about antennas

[polo807]

Hello
(1)This question is for the Saint Louis City and County area. I have noticed that some not all police cars have 3 short antennas behind the light bar and in the city the pig tail is behind them or the pig tail is on the trunk.
And the county has the same set-up except for there larger VHF antenna on the truck lid .One of my neighbors is a County Police officer and his take home car has the Motorola Astro XTL 5000 with the same set up I mentioned.
Is this for the lo-jack system or for the future ENC?

(2) Also what mobile antenna should I buy if I want to hear MOSWIN, Saint Louis (Pre-Fully Enc) and Saint Louis County or will I need two antennas and if so what would I need to connect them to my scanner? 996xt

Thank you for your replies.

 

[kruser]

Hello
(1)This question is for the Saint Louis City and County area. I have noticed that some not all police cars have 3 short antennas behind the light bar and in the city the pig tail is behind them or the pig tail is on the trunk.
And the county has the same set-up except for there larger VHF antenna on the truck lid .One of my neighbors is a County Police officer and his take home car has the Motorola Astro XTL 5000 with the same set up I mentioned.
Is this for the lo-jack system or for the future ENC?

(2) Also what mobile antenna should I buy if I want to hear MOSWIN, Saint Louis (Pre-Fully Enc) and Saint Louis County or will I need two antennas and if so what would I need to connect them to my scanner? 996xt

Thank you for your replies.

I'm not sure on the antennas but for the MOSWIN system that is going in, I've been told that it will be an 800 MHz system in our area as well as the other large metro areas which I assume is just Kansas City.
Now if we will be able to hear other systems in the MOSWIN system or not is unknown until they actually start building the system here.
If we can, then some type of VHF antenna would be best.
I think the reason that MOSWIN will be 800 in the major metros is simply because they already have 800 systems in place. I suppose it is also possible that MOSWIN will just use the existing systems.
The county is building an 800 system now so they could use that or they could use the STL system. They could even show up on the 700 system out in St. Charles. I bet they do really as all those systems are tied together and I expect the new county system will also be a part of the big picture.
The STL system and the system out in KC (Independance) are one in the same even though they are located across the state from one another. I think they carry the same system ID's.

 

[hkrharry]

The 3 antennas your seeing are the ETL locator DF antennas.
The is for the transmitter pack that the banks drop into the bag in case they get a hold up.
allows the LEOs to track the bag. Operates in the 216 mhz area. Has a sound similar to the old style 121.5 ELT beacons.

HH

 

[hkrharry]

More on the ETL system for those that want to know.....

The back end has receivers placed at strategic points around the metro areas and is fed back to the servicing dispatch points and they have a map that shows what quadrant the signal is coming from then the roving cars use their in car units to DF the signal down and hopefully catch the bad guy.
73
Harry

 

[stlouisx50]

I knew nothing about the devices but did a quick search and found this site IDEAL INDUSTRIES, INC. - LANTEK® 6/6A/7G Cable Certification Testers

The site has 350 MHz 500 MHz 1 GHz devices

A neat video on youtube about the type of devices - 406 MHz Emergency Locator Transmitters - YouTube

 

[nd5y]

I knew nothing about the devices but did a quick search and found this site IDEAL INDUSTRIES, INC. - LANTEK® 6/6A/7G Cable Certification Testers

The site has 350 MHz 500 MHz 1 GHz devices

A neat video on youtube about the type of devices - 406 MHz Emergency Locator Transmitters - YouTube

Cable testers have absolutely nothing to do with law enforcement tracking transmitters and neither do 406 MHz EPIRBs

 

[stlouisx50]

I see you are correct. I found the following

Radio Spectrum - 174 MHz to 328.6 MHz

174 - 180 MHz
television channel 7
Biomedical telemetry devices, 1500 microvolts/meter at 3 meter max. [15.241]
180 - 186 MHz
television channel 8
Biomedical telemetry devices, 1500 microvolts/meter at 3 meter max. [15.241]
186 - 192 MHz
television channel 9
Biomedical telemetry devices, 1500 microvolts/meter at 3 meter max. [15.241]
192 - 198 MHz
television channel 10
Biomedical telemetry devices, 1500 microvolts/meter at 3 meter max. [15.241]
198 - 204 MHz
television channel 11
Biomedical telemetry devices, 1500 microvolts/meter at 3 meter max. [15.241]
204 - 210 MHz
television channel 12
Biomedical telemetry devices, 1500 microvolts/meter at 3 meter max. [15.241]
210 - 216 MHz
television channel 13
Biomedical telemetry devices, 1500 microvolts/meter at 3 meter max. [15.241]
216 - 216.880 MHz
Automated Maritime Telecommunictions System ("AMTS"): Mississippi River and connecting waterways, Gulf of Mexico [80.385(a)] - Not currently assignable [80.385(a)(2) footnote 2]
Low Power (100 mw ERP max.) Radio Service (LPRS) [Part 95 Subpart G and 95.629] (See FCC News Release, July 25, 1996) to include:

auditory assistance devices for persons with disabilities
health care assistance devices for persons with illnesses
law enforcement tracking systems
point-to-point network control communications for Automated Maritime Telecommunication Systems (AMTS).

Wildlife and ocean buoy tracking and telemetry [90.248]
216.880 - 217.0 MHz
Automated Maritime Telecommunictions System ("AMTS"): Mississippi River and connecting waterways, Gulf of Mexico [80.385(a)] - Not currently assignable [80.385(a)(2) footnote 2]
US Navy SPASUR system [80.385(a)(2)]
Low Power (100 mw ERP max.) Radio Service (LPRS) [Part 95 Subpart G and 95.629] (See FCC News Release, July 25, 1996) to include:

auditory assistance devices for persons with disabilities
health care assistance devices for persons with illnesses
law enforcement tracking systems
point-to-point network control communications for Automated Maritime Telecommunication Systems (AMTS).

Wildlife and ocean buoy tracking and telemetry [90.248]
217.0 - 217.080 MHz
Automated Maritime Telecommunictions System ("AMTS") coast transmit: Mississippi River and connecting waterways, Gulf of Mexico [80.385(a)]
US Navy SPASUR system [80.385(a)(2)]
Wildlife and ocean buoy tracking and telemetry [90.248]
217.080 - 218 MHz
Automated Maritime Telecommunictions System ("AMTS") coast transmit: Mississippi River and connecting waterways, Gulf of Mexico [80.385(a)]
Wildlife and ocean buoy tracking and telemetry [90.248]
218 - 219 MHz
IVDS (Interactive Video and Data Services)
Wildlife and ocean buoy tracking and telemetry [90.248]
219 - 220 MHz
Automated Maritime Telecommunictions System ("AMTS") ship transmit: Mississippi River and connecting waterways, Gulf of Mexico [80.385(a)]
Amateur point-to-point fixed digital message forwarding systems, including intercity packet backbone networks, on a secondary basis [Part 97]

Summary in Daily Digest. March 17, 1995
FCC AFFIRMS SECONDARY USE BY THE AMATEUR RADIO SERVICE. January 29, 1996

Wildlife and ocean buoy tracking and telemetry [90.248]
220 - 221 MHz
Land mobile - base stations [Part 90 Subpart T]
221 - 222 MHz
Land mobile - mobile stations [Part 90 Subpart T]
222 - 225 MHz
Amateur (1.25 meter band) [Part 97]
225 - 243.00 MHz
Military [2.106 footnote G27]
243.00 MHz
Survival craft stations, ELTs [87.195]
243.00 - 328.6 MHz

 

[hkrharry]

More on the ETL system for those that want to know.....

The back end has receivers placed at strategic points around the metro areas and is fed back to the servicing dispatch points and they have a map that shows what quadrant the signal is coming from then the roving cars use their in car units to DF the signal down and hopefully catch the bad guy.
73
Harry

Here the web site for the folks who make the tracking device.

ETSTRACKING.COM

And what a typical in car unit looks like.

 

[stlouisx50]

Thats very neat. Thanks for the post.

 

[harrisjt]

yes ETS is correct for this technology these have been in use since the 70s its commonly used at a few banks as a bank robbery money tracker and in larges cities like STL is also used for babies that are taken from the hospital... they are a product line called PRO-net it is setup like this, receive antennas in quite a few areas usually on the agency towers etc etc each agency that uses this system has a monitor in the dispatch center that has a map of the area and will alert when a RX site goes "hot" (bank money tag or baby band is activated) and it indicates the signal strength, dispatch alerts and then the mobile units will drive the area as they have a direction finder/ sig strength indicator (like a fox hunt so to speak) the in car indicator shows sig strength and position in reference to the car ( N, S, E or W) its being phased out to new technologies but by far the pro net is the most easiest to use. I have to say all the traning ive had to go through over the years is fun!