Pro 106 discriminator tap

Hi guy's
We discussed the discriminator tap a while back, and I lost all the info except the pics in the wiki. Heres my question(s)
Has it been successful / does not interfere with reception/any signals?
Does it also trbo trunk, like ltr or????
I'm still game to do it, just cautious. I've read someone else fried their 106 while attempting it.
And, can we have some more detailed info on connection to which part?
P.M me, if you don't wanna tie up the page
Thanx

I remember one person frying their 106 and I remember one person being successful. The connection goes to TP4. The board should be labeled. Looking at the pics of the breadboard part the connections he made it looks like this: (if you can tell what I'm trying to draw)

TP4--------47k resistor --------10uf capacitor---------------| + Mono Jack or + Left Tip Stereo |
Chassis Ground or Antenna Ground-----------------------| - Mono Jack or - Ground Stereo |

Pro-106 Discriminator Tap - The RadioReference Wiki

I dont think any computer software does trunking. I dont know if its even possible since the software on the computer can't tune the scanner to the voice channel.

Is this the first time you tapped a radio?

It will be. I am looking into joining a ham group that has technicians, digital. So, 1 of them has the talent to do it. That is if he is willing. I got the pics, just need more detail, so we get it right.. I wouldnt go after it but I am surrounded by it, BAD, BAD, BAD... So, why not scan it, even if it's hard to get there. Those parts? I still gotta google, e-bay them.

That isnt a 47k resistor according to the color of the bands.
4 Band Resistor Color Code Calculator and Chart

Appears to be 47 ohms. So not sure what to tell you there. I have a 10k resistor (no capacitor) in my Uniden and seems to work well but its plugged up to the line in on the soundcard and not the mic jack.

Radio Shack has all the parts you need. I used a wire from the inside of an rca wire. I think it was 28 gauge but cant remember. Its very small wire.

I dont understand by --line--
Let me clear it up-- what I assume;
You put this stuff into scanner, and bingo--instant trbo decoding, hope I'm right..

Each line below is a wire inside the scanner for the connections. This is a poor attempt at a schematic. The top line is positive and the bottom line is negative. I'll try to redo it here.

| TP4 |--------| 47k resistor |--------| + 10uf capacitor - |---------------| + Mono Jack or + Left Tip Stereo |
| Chassis Ground or Antenna Ground |-----------------------------------| - Mono Jack or - Ground Stereo |

So for the positive (red wire), solder on to point TP4 then you will have a resistor and capacitor in series connected to the + of a mono jack. Note the polarity of the capacitor.
Then for the negative (black wire), you connect the - post of the mono jack to a scanner ground.

Well you put this stuff into the scanner and use software to decode turbo, p25, nexedge and such. Just depends on what software you use. You cant decode encryption. Have a look at DSD and DSD+.

Also have a look at
Discriminator output - The RadioReference Wiki

and here (select a reciever).
Discriminator Output

to see many more descriminator taps and to get an ideal of what is done.

The photos make the connection point look big but it is really small and hard to see. That was the main thing for me. Your supposed to use a magnifying glass but I didnt. I have 20/20 vision.

Another pointer I can give you if you decide to do it yourself is tin a small amount of solder to the end of your wire then put the wire on the connection point and heat the wire with the soldering gun, not the connection point, to the point where it just melts to it then remove the heat. Make sure you have a steady hand.

mainetrunk said:

You put this stuff into scanner, and bingo--instant trbo decoding, hope I'm right..

Click to expand...

Not quite that simple.
The discriminator tap just taps the unfiltered audio inside the scanner. That unfiltered audio is routed to a jack of your choice that you install on the rear of the scanner by drilling a hole in a blank space of the rear chassis. Most people will use a 1/8th inch stereo or mono jack but some use a RCA or Phono jack to avoid confusion with external speaker jacks.

Then you use a simple patch cord that plugs into your new jack and the line in jack on a computer. The computer will be running DSD or DSD+ software. That software is what does the decoding back to speech which will come out of the computers speakers.
The reference to "line" are for the line or mic input jacks on your computer. That is how you get the signal from your tapped scanner into the computer so DSD can decode it.

One of the DSD versions only runs under Linux but I think the DSD+ version may run under Windows. I've never tried the windows version.

Read the links that jfhtm350 posted for you as they will explain much of it.
There is also a forum here for discussing what you are attempting. It may be the place to ask questions if you cannot get things working.
Digital Voice Decoding Software - The RadioReference.com Forums

better off to buy a 10-20 dollar dongle cheap and easy lol

reconrider8 said:

better off to buy a 10-20 dollar dongle cheap and easy lol

Click to expand...

I second this suggestion. I have a couple of them and don't regret going this route. It's cheaper than potentially bricking an expensive digital scanner and comes in a USB package for use with a computer that will be needed for DSD anyways to decode digital audio.

I had a feeling it was not that easy. OK, thanks. If dsd can be trusted in your computer---can it?

I've used Unitrunker, DSD+ and some more. I havent seen any security concerns.

mainetrunk said:

I had a feeling it was not that easy. OK, thanks. If dsd can be trusted in your computer---can it?

Click to expand...

DSD, and DSD+ doesn't try to connect to the internet, I don't understand why You think they can't be trusted.
Do You know something we don't?

DSD+ will if you use lrrp for the tile server.

Dongle help

reconrider8 said:

better off to buy a 10-20 dollar dongle cheap and easy lol

Click to expand...

Do you have more info on the type or model of dongle that would work ? i see some on ebay , but it looks like they are for receiving forign TV
Any help would be appreciated..

Thanks

jfhtm350 said:

DSD+ will if you use lrrp for the tile server.

Click to expand...

You are correct on that.

Chronic said:

Do you have more info on the type or model of dongle that would work ? i see some on ebay , but it looks like they are for receiving forign TV

Click to expand...

That's basically what RTL-SDR is. It was originally designed to be a DVB-T USB TV Tuner but someone discovered that the RTL2832U chip could be used as a radio instead.

As for the particular type or model, most people end up getting the R820T chip as it's the cheapest and most widely available on the market. I've tried buying one from China for less than $10, which arrived dead a few weeks later, and then bought a Newsky TV28T from kbellenterprises and another from NooElec in North America. The latter two have worked rather well for my purposes so far.

It's important to note that RTL-SDR is a little bit more involved than simply using a scanner and might not give you the results you want initially. There's plenty of resources and help available through a Google search and on the Software Defined Radio section of these forums.