Discriminator Tap

[baddandy23]

Dumb question, but is the discriminator tap on the Pro95 or 96 the same as the PC/IF jack? Or is the tap a mod that has to be installed seperatly? And if so, how is it done in a nutshell?

 

[ka3jjz]

No, the 2 are very different. The PC/IF port is for the programming cable; a discriminator tap is used to tap out the baseband audio off the discriminator before it gets rectified by other stages.

In a nutshell, you would need to find the correct pin in the discriminator circuit, find a way to mount an external jack onto the unit that would not interfere with other functions....then wire the jack and the discriminator point together. Oh yes, you'd no doubt have to be very comfortable with SMT (surface mount technology), as most newer rxs these days use it.

73s Mike

 

[crayon]

The Pro-95 is one of the quickest radios to discriminator tap.

Take the four screws out of the back of the radio and crack the case. On the circuit board, between the squelch and the volume controls is TP4. Solder a cable to that.

Next, (moving to the right) you will see CN3 and then R139 and R138. Solder another cable to R138, then solder both of those cables to a 1/8 jack. Your radio is tapped!

I have found that mounting the 1/8 jack by drilling a hole right beside the PC/IF jack almost makes it look factory. There is a fake seam in the case to the right of the PC/IF jack, if you will drill in the center of that .. it looks good. Start out with a very small drill bit as plastic will "grab" your bit and mangle the plastic. If you do not have a tiny drill bit, go out and buy some. Then work your way up to the correct size to mount the jack.

pro92b has some good tips on what values of C and R to use to isolate the radio from the slicer ...

 

[baddandy23]

so is it then not possible to use mtrunk or etrunk without the tap?? thanks

 

[ka3jjz]

so is it then not possible to use mtrunk or etrunk without the tap?? thanks[/quote

Yes, but that's not the only thing you would need; you also need something commonly referred to as a data slicer. There are still 1 or 2 companies that sell them; briefly put, they take the signal from your tap and change it to a RS232 signal that a PC can read.

In addition, if you're the tinkering type, this site has schematics for data slicers. These are external devices, though if there's enough room I know of a few folks that have put them inside their scanners.

73s Mike]

 

[crayon]

Yes, but that's not the only thing you would need; you also need something commonly referred to as a data slicer. There are still 1 or 2 companies that sell them; briefly put, they take the signal from your tap and change it to a RS232 signal that a PC can read.

ka3jjz,

T4Win and the new Windows trunker port "Motorola Trunker32" do not need a data slicer to operate correctly. So if someone discriminator taps a radio and feeds that to a soundcard .. they are good to go.

:wink:

 

[baddandy23]

well i guess what i am getting at is I was wondering if I can run Mtrunker without putting a tap into my pro 95 or pro 96? do i just need the data slicer, or do i need the data slicer and a tap. and where would i get a slicer at?

 

[ka3jjz]

well i guess what i am getting at is I was wondering if I can run Mtrunker without putting a tap into my pro 95 or pro 96? do i just need the data slicer, or do i need the data slicer and a tap. and where would i get a slicer at?

As''crayon" mentioned in his last message, if you're going to run T4Win (I could never get anything at all out of it) or this new ported Motorola Trunker32, then a data slicer is not needed.

However, the older Etrunker and Trunker do need a data slicer, and I've bought and used the slicers sold by:

http://www.dataslicers.com/

to good success.

But in all cases, yes, you do need a tap to make this work. You cannot use the audio out of the earphone jack because it cannot carry the high speed data without distortion and truncation.

73s Mike

 

[N7OLQ]

Another question. It has been a while since I ran T4Win, but at the time, it could not control a second scanner to hear the audio. Does T4Win or the Windows Trunker offer this feature now?

 

[scanfan03]

Windows trunker port "Motorola Trunker32" do not need a data slicer to operate correctly.

Where can I find this program at? I already use T4Win, but maybe this one is better since T4Win hasn't been updated in like a year.

 

[scanfan03]

Well I found it!!

 

[RTAdams89]

I'm about to do this but want to confirm a few things first.
1) Is R138 the bottom tan resistor of the two?
2) Which side of the resistor should I solder to?
3) Which wire should go to which part of the audio jack?

 

[321cm]

http://www.naturalgfx.com/pro97_discriminator.htm I did that on the Pro-95, just solder a wire to "TP4". Works with out dataslicer with UniTrunker.