Didn't hear the THP ?

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Rocky3

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I made a trip up 75 from GA to IN yesterday. I imported the frequencies from radio reference and put them on my Pro-106. But I didn't hear the THP entire way through TN. I had no problems listening to any of the other states highway patrols. It looked like the THP are analog, is there maybe a digital system out there they are using I am missing ?
 
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jimg

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I made a trip up 75 from GA to IN yesterday. I imported the frequencies from radio reference and put them on my Pro-106. But I didn't hear the THP entire way through TN. I had no problems listening to any of the other states highway patrols. It looked like the THP are analog, is there maybe a digital system out there they are using I am missing ?

In general you need a mobile antenna, with a whip that will receive the 42mhz band to hear them. If you were just using a "rubber duckie" type antenna you probably wouldn't pick them up. Also, you would need to be within a few miles of the trooper to pick up the mobile, unless you hear them on a repeater/link. I think they have some of these repeaters in the 70 mhz (mid-band) in that area of the State. Also, they use VHF and UHF repeaters (see RR database), but some repeaters are on micro-wave, which cannot be received by a scanner.
 

Rocky3

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In general you need a mobile antenna, with a whip that will receive the 42mhz band to hear them. If you were just using a "rubber duckie" type antenna you probably wouldn't pick them up. Also, you would need to be within a few miles of the trooper to pick up the mobile, unless you hear them on a repeater/link. I think they have some of these repeaters in the 70 mhz (mid-band) in that area of the State. Also, they use VHF and UHF repeaters (see RR database), but some repeaters are on micro-wave, which cannot be received by a scanner.

I think that was my issue, the other systems I was listening too where in the 800mhz range and seemed to come in pretty clear with the stock antenna. But that 42.xxx signal seemed to be impossible for me to pickup.
 

rma0100

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THP Listening

THP has a ton of frequencies and I have them all programmed in. The most common use is low band and the one I hear the most is 42.42. They do use repeaters but not all the time. It's a complex system. Even though in other states I could hear low band State Police bobiles for about a 20 mile radius I cannot hear THP unless their within 5-7 miles from my location on 42.42. I use the best of equipment, a XT996D, 796D, and a Rohde & Schwarz sapectrum analyzer capable of up to 5.2 Ghz..

While monitoring the 42.42 on the Uniden 996 I watch the 153.00-157.000 Mhz band on the SA for anything that comes up simultanously. I do see the repeates but not all the time.

The R&S SA has a sensitivity of .002 Uv so I'm not missing anything. I also use a good antenna for low band and VHF. I can see signals well below -115 Dbm

THP is just hard to copy, especially the mobiles.

I'm going to look up those Microwave repeaters and try them but that's pretty directional so I prob won't have much luck there also. If I see anything I'll list it within the forums.
 

mdgjedde

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Good information here...I monitor the THP and hear calls intermittently. Their frequency list is somewhat bewildering.
 

rngr2000

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Knowing that the THP 42.42 doesnt have much range can be a good thing. Im using a PRO 163 with a RS 20-032 antenna. If I hear THP on 42.42 I know they are near by and watch my speed a little closer ;)

I hear dispatch on 452.45 in my area.
 

W4EMS

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They are using MDT's for as lot of their traffic now. I went from Kingsport to Nashville last night and did not hear a peep from THP.
 

jfhtm350

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I heard a THP come on the Hamblen Co Sheriffs channel, but could not pick him up on the THP frequencies after that. Probably because he was in the next county over i assume. There are a couple of THP Repeaters that makes all kinds of sounds and i cant figure out if it is digital or just out of range of my scanner.
 

ButchGone

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Adding to the already complex mix is the upcoming use of the Tennessee Valley Regional Communications system using P25 digital on 700Mhz. While there doesn't seem to be any activity yet some people at THP say the Knoxville and Chattanooga posts have the digi system in their consoles and radios for cars/portables are being put into place. I did hear THP Nashville on the system testing some time ago on talk group 1 which is used for system wide tests. We'll see how much they use it in light on heavy MDT use but they will have capability to communicate with the countries on this system. Keep your ears open for new talk groups!
BG..
 

jimg

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They are using MDT's for as lot of their traffic now. I went from Kingsport to Nashville last night and did not hear a peep from THP.

I went to Chattanooga yesterday and picked up the Chatt. post several times on 42.42 and the cars a couple of times on 42.26. (I am using a long whip.) Also, heard traffic on 72.78 one time.
 

wxwarn285

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I hear dispatch only on 42.42, car to dispatch on 42.26 mainly in the county north west of you in maury. I fully don't understand how thier system is setup. If you have any information on their system setup, I would like to hear about it.
 

jimg

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I haven't heard anything at all (ZERO!) from the Nashville district or cars in weeks.

I heard the Nashville post yesterday on 42.36 and 42.56, and a couple of cars that were close by when I was traveling down I-24 in the M'Boro area. I am using a 396XT with a GRE pre-amp and with a long whip.
 

W4EMS

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I expect you would with that setup. Does the pre-amp not overload Smyrna and Nashville trunking?

I hear 42.56 frequently wit the 800 rubber duck. Still looking forward to the statewide 700 system. TEMA and Roane county were crystal clear.
 

jimg

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I expect you would with that setup. Does the pre-amp not overload Smyrna and Nashville trunking?

I hear 42.56 frequently wit the 800 rubber duck. Still looking forward to the statewide 700 system. TEMA and Roane county were crystal clear.

Yes it does overload, so I have the pre-amp mounted so I can just turn it off and by-pass it so it won't overload Smyrna and Nashville. Also, in the database for the new Tennessee Valley system, I noticed that in the system talkgroups that 1471, 1473, 1475, and 1477 are allocated for THP District 3, which is the Nashville district. I programmed these into my GRE-500 but have not received any radio traffic, thus far. I think I read in one of the posts in this forum that this system was going to be tested sometime this year in Williamson Co. first. Do you know anything about this? Right now I only receive TEMA Ops and MTSU on the Tennessee Valley system.
 

W4EMS

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Not able to confirm the Williamson rumors. They just recently upgraded their county comms to simulcast. That said Bill in the EOC is very progressive so time will tell.

I have been able to hear more of the MTSU system. Wondering if they have increased power or have a new tower. I have not heard THP on this system.

If all of them sound like the Roane Co setup this will be a nice statewide system.
 

jimg

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Not able to confirm the Williamson rumors. They just recently upgraded their county comms to simulcast. That said Bill in the EOC is very progressive so time will tell.

I have been able to hear more of the MTSU system. Wondering if they have increased power or have a new tower. I have not heard THP on this system.

If all of them sound like the Roane Co setup this will be a nice statewide system.

Yes, I'm looking forward to THP going on the TN Valley system. Then I probably won't need the whip and pre-amp to pick them up. Also, I did hear that some of the cars in the Chattanooga district (#2) already have the new radios installed in their vehicles.
 

jimg

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THP has a ton of frequencies and I have them all programmed in. The most common use is low band and the one I hear the most is 42.42. They do use repeaters but not all the time. It's a complex system. Even though in other states I could hear low band State Police bobiles for about a 20 mile radius I cannot hear THP unless their within 5-7 miles from my location on 42.42. I use the best of equipment, a XT996D, 796D, and a Rohde & Schwarz sapectrum analyzer capable of up to 5.2 Ghz..

While monitoring the 42.42 on the Uniden 996 I watch the 153.00-157.000 Mhz band on the SA for anything that comes up simultanously. I do see the repeates but not all the time.

The R&S SA has a sensitivity of .002 Uv so I'm not missing anything. I also use a good antenna for low band and VHF. I can see signals well below -115 Dbm

THP is just hard to copy, especially the mobiles.

I'm going to look up those Microwave repeaters and try them but that's pretty directional so I prob won't have much luck there also. If I see anything I'll list it within the forums.


I think the microwave relay the THP uses at the St. Andrews firetower, (I-24/Monteagle area), is 955.800, call sign WNEX 883. If you have some kind of search capability on these towers, I would be interested in what you find out. (The license may be to another State agency, like conservation, someone said.) Everytime I have ever driven by that firetower all I hear on 955.800 is a strong continuous carrier, but with no modulation whatsoever. (?)
 
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