Help with THP monitoring

[Airdorn]

Help with TN Hwy Patrol monitoring

Hi all. I'm in Shelby County.

When monitoring the THP based on the frequencies given in the RR database, all I ever hear is dispatchers answering someone, and I rarely hear even that. I never hear the mobiles in the trooper's cars.

I have 42.420, 42.560, etc. programmed into the scanner... all the freqs in green on the left side int he table fir District 4 - Memphis.

Occasionally, I'll hear what sounds like morse code that lasts for about 5 seconds, but that's all.

Does anyone know how to monitor the TN Highway Patrol? What am I doing wrong?

I am using a BCD996T with the freqs programmed in in conventional mode.. using a Scantenna mounted 25' on a mast outside.

Thanks in advance!

Airdorn

 

[Airdorn]

Nevermind... after writing this, I read a bunch of other msg's about THP, in this forum. It's a pretty confusing system. Looks like you need to be very close to the trooper's cruiser to get that side of the audio in most cases.

 

[CAPTLPOL1]

If you are able to place a good antenna tuned to 42 MHz outdoors, then you stand a chance to picking up the Troopers talking to dispatch. If you are using the rubber duckie, then you will need to be pretty close to them. A mag mount on a pie pan will help some. An outdoor antenna mounted up high will help out greatly. With low band you will need to be sure that the antenna is tuned pretty good to pick up those signals.

 

[kf4lhp]

I feel your pain...

Nevermind... after writing this, I read a bunch of other msg's about THP, in this forum. It's a pretty confusing system. Looks like you need to be very close to the trooper's cruiser to get that side of the audio in most cases.

In a nutshell...

• F1 - dispatcher is on 42.420 MHz, cars are on 42.260 MHz. There is no repeater.
• F2 - car to car simplex on 42.420 MHz.
• F3, F4 - dispatcher and cars are on the same frequency - i.e. simplex.
• F5, F6, F7, F8 - normal repeater operation.

I have a similar setup to you, a Scantenna about 25 feet up or so. I'm getting the Chattanooga dispatcher from at least two different sites, and cars reliably within 10 miles. That said, I'm not really near the interstate, and the terrain here is quite different from the flatlands of Memphis.

I'm thinking one of the towers that was taken down a while back by the tornado in Shelby County was THP's. This could also have a significant impact on your reception if that site hasn't been put back in operation.

 

[Airdorn]

Yeah, I have all those freqs. programmed (the ones for District 4, that is) in the way you mentioned, but I very rarely get anything at all.

What I do occasionally get is something that sounds a little like morse code that lasts for a few seconds, and also some THP dispatcher talking to someone. When the dispatcher is talking, the signal is VERY clear and strong. But this might only happen a couple of times a day.

Airdorn

 

[n4yek]

In a nutshell...

• F1 - dispatcher is on 42.420 MHz, ........ There is no repeater.

• 
  There are actual repeaters, you probably have never noticed unless you monitor the tower to base frequencies listed below.
  The tower transmits, in your location, on 42.42 Mhz, the cars talk back to the tower on 42.26 Mhz, the tower talks back to dispatch on a link frequency. In my area here in District 5, that link is 72.02 Mhz. You might be able to find your area from the list below. If you find it, just enter the freq into your scanner and you will be able to hear the Troopers replying, and they don't even have to be near you.
  72.0200
  72.3000
  72.5800
  72.6800
  72.7800
  72.8600
  75.8000
  75.8800
  75.9600
  451.5500
  452.2500
  452.2750
  452.4500
  457.2500
  457.2750
  457.4500

 

[kf4lhp]

There are actual repeaters, you probably have never noticed unless you monitor the tower to base frequencies listed below.

Danny is completely right. When I say there are no repeaters, I mean repeaters where you will hear both the dispatcher and cars. That said, there are the 72/75 and 452/457 MHz links which you can pick up if they are being used in your area.

I know here in Chattanooga, there is a 72/75 MHz link between Chattanooga post and Benton, and up in Cookeville there are at least two 452/457 MHz links to remote sites. However, some sites are linked back to the post by microwave, so don't be surprised if you can't find any active link frequencies.

 

[Airdorn]

There are actual repeaters, you probably have never noticed unless you monitor the tower to base frequencies listed below.
The tower transmits, in your location, on 42.42 Mhz, the cars talk back to the tower on 42.26 Mhz, the tower talks back to dispatch on a link frequency. In my area here in District 5, that link is 72.02 Mhz. You might be able to find your area from the list below. If you find it, just enter the freq into your scanner and you will be able to hear the Troopers replying, and they don't even have to be near you.
72.0200
72.3000
72.5800
72.6800
72.7800
72.8600
75.8000
75.8800
75.9600
451.5500
452.2500
452.2750
452.4500
457.2500
457.2750
457.4500

I have ALL those programmed conventionally, but I don't get anything from them except for a bit of 'popping' every so often that may be a couple of milliseconds of some communication... its hard to tell.

I've programmed those 72/75 repeater frequencies, the ones listed for my area (District 4), and also those other repeater frequencies in the 400mhz range.

I still get nothing. Surely THP uses radios... they don't pull;-over and send-up smoke signals. Their cars have no less than 5 antennas of all sizes on their trunks!

So I'm missing a big piece of the puzzle here.

Oh well, thanks for all the help!

Airdorn

 

[motoapco25]

A mag mount on a pie pan will help some.

Thats Hamsexual lol

 

[kf4lhp]

THP also has VHF extenders on 154.905; you may want to plug this one in to your scanner as well. If there is a car nearby and the trooper has his extender turned on, you'll hear any low band traffic (albeit "choppy" due to the listen-back delay on the extender).

 

[jimg]

I have ALL those programmed conventionally, but I don't get anything from them except for a bit of 'popping' every so often that may be a couple of milliseconds of some communication... its hard to tell.

I've programmed those 72/75 repeater frequencies, the ones listed for my area (District 4), and also those other repeater frequencies in the 400mhz range.

I still get nothing. Surely THP uses radios... they don't pull;-over and send-up smoke signals. Their cars have no less than 5 antennas of all sizes on their trunks!

So I'm missing a big piece of the puzzle here.

Oh well, thanks for all the help!

Airdorn

Are you using an outside antenna, mobile or base? I don't think you can pick the signal up on a standard rubber duckie unless you are VERY close to the base or car.

 

[n4yek]

Are you using an outside antenna, mobile or base? I don't think you can pick the signal up on a standard rubber duckie unless you are VERY close to the base or car.

I can pick the link freqs up with my HT inside my house on a rubber duck and I am probably 10 miles from the tower.

 

[jimg]

I can pick the link freqs up with my HT inside my house on a rubber duck and I am probably 10 miles from the tower.

I also pickup the UHF Links on a rubber duckie when listening to Nashville THP when I'm in Murfreesboro, but not the low band, 42.36 mhz. To listen to low-band, I've always needed a mobile or base antenna.

 

[n4yek]

I also pickup the UHF Links on a rubber duckie when listening to Nashville THP when I'm in Murfreesboro, but not the low band, 42.36 mhz. To listen to low-band, I've always needed a mobile or base antenna.

My link freqs I am referring to are in the 72MHz range, I can hear dispatch inside my house on the ht and that is on 42.42MHz. I guess i'm lucky.

 

[xmguy]

I have a pro-91. Do the THPs use any trunking? Preferred analog. I'd like to listen to them. Unless they've changed to a IDEN network.

 

[Airdorn]

They're all old-fashioned, conventional.

 

[xmguy]

They're all old-fashioned, conventional.

Are they frequencies universal regardless the location? I also have a telescoping radio shack antenna with ferrite antenna in the middle would this help pull in the signals from the THPs.

 

[CAPTLPOL1]

The database has plenty of information on THP.