Discriminator "tap"?

[ka5lqj]

Hi,

I thought I knew something about 800 mhz trunking, but I guess I don't, LOL! I've seen post here and other places that talk about "tapping the discriminator" on a scanner. Now, NOT wanting to destroy my scanner (vision problems), just what good is this? Does the tap connect to a computer so you can "see" what "data" is being sent to the DT's (Display Terminals) in the police cars and fire trucks? Wouldn't that be neat? LOL! Well, I'm just 'nosey'. IF that isn't it, then what does the "tap" do. I certainly don't want to hear the 'buzzsaw' or warble tones all day.

I have ANOTHER question, but I'll post that on another post. ;-)

Respectfully,
73,

Don/KA5-LQJ
Grid Sq: EM-32-cl

 

[ka3jjz]

No, viewing the data sent to cops' display terminals in general can't be done anymore - it's all encrypted, as well as being illegal. What a discriminator tap allows you to see - sometimes with a seperate item called a data slicer - is a trunking system in a great deal more detail than you can with trunktracking scanners. Our wiki has several links that discuss this in detail. Click on 'wiki' in the blue toolbar, then scroll to 'Forum Specific Topics' down to 'Trunked Radio Decoders' for more info.

Setting up a trunking bank so you don't hear that gawd-awful buzzsaw is different for RS and Uniden scanners. However we have lots of help in our wiki - but first, most importantly, what scanner are you using and what system are you trying to hear? Our database has lots of information on trunking systems, indexed by state. Our forums (also indexed by state) are a good place to get such help.

73s Mike

 

[DickH]

Hi,
I thought I knew something about 800 mhz trunking, but I guess I don't, LOL! I've seen post here and other places that talk about "tapping the discriminator" on a scanner. Now, NOT wanting to destroy my scanner (vision problems), just what good is this? Does the tap connect to a computer so you can "see" what "data" is being sent to the DT's (Display Terminals) in the police cars and fire trucks? Wouldn't that be neat? LOL! Well, I'm just 'nosey'. IF that isn't it, then what does the "tap" do. I certainly don't want to hear the 'buzzsaw' or warble tones all day. ...

A discriminator "tap" gives you access to the control channel data stream before it goes through the audio filters. That signal can be used by Trunker and other programs to read the info in the data stream and display it on your PC. It does NOT read MDT signals, most of which are encrypted anyway.

 

[ka5lqj]

"Thanks", Gentlemen,

I didn't know information being sent to the MDT's was encoded and illegal to intercept. I have no desire to have the rath of the Federal Government on my back. I don't have 'Trunker', so it really becomes a moot point. I was just curious.

Scott, I have several scanners, but the one I'm setting up now is the Pro-95. I live in Shreveport, LA., the 3rd largest city in the State and also the 3rd largest gaming ("gambling" is STILL illegal in Louisiana, LOL! Symantics, Sheesh!) center in the USA....The "Gateway to HELL".

I'm a ham radio op, besides a scanner freak, hi hi. I'm developing a 'database' for stations within a 125 mile radius of Shreveport. Now, I'm not crazy enough to believe that I'm going to hear police or fire calls from 125 miles out on 800 mhz Trunked, but I could hear some in the 25-50 mc and 150-174 mc band. The database coverage will be *band dependent*, so I don't have stations I'm trying to hear way far out that don't have a snowball's chance in Hades of making it in.

With the Icom 706MkII-G I have and a dual-band "J-pole" at 50 feet, I can hit & 'hold' the 147.33 repeater in Alexandria, LA. just over 125 miles south of Shreveport. I can also access the repeater's in Monroe, LA., 100 miles east with just 50 watts.

I'd LOVE to find a small database that would allow me to input callsigns and data and have it, at the same time, search to tell me if I've made a contact before, what band, and what date and time, then allow me to "add" the contact and *attatch* it to that first contact, like being electronically "stapled" to it, on that page. Make sense?

Well, the wife says , "Supper's ready", LOL!

Blessings,
Respectfully,
73,

Don/KA5-LQJ
Grid Sq: EM-32cl
10/10#: 53243
NBSRC Chapter #2
NBSRC #: 3224