Pro-95 and Trunking software

[Spadinator]

I have been using Trunk88 with my Pro95 and had a computer upgrade. Now I can't get it to work. I have tried to set it up for the Pro95 but no longer see that option. Any ideas?

 

[loumaag]

To use the Pro-95 as what? The Pro-95 can't be controlled so if you mean as a source radio, what difference does it make?

 

[Spadinator]

I have a tap put in and it has worked fine in the past.......for some reason when the computer was replaced it no longer works.

 

[loumaag]

Ah, so it has nothing to do with the Pro-95, that is what I was wondering. I am guessing that it is a COM port problem, if what you say is accurate. Use the system manager to check what your ports are doing. This is before you try and run Trunk88. With a computer upgrade, you will have to reconfigure what port is handling the data stream.

 

[Comint]

Audio from the tap comes in via the Soundcard, so TRUNK88 needs to be configured for the new Soundcard.

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Comint

 

[Spadinator]

I believe I found the problem. I am getting a dirty signal from the scanner. It looks like maybe the tap got shorted or burned out some how. I got the computer to find the scanner and sound card but can't get a good enough signal to decode it.

 

[Spadinator]

I changed to a different scanner as my source. I tapped a Pro-92 and it works with Trunk88 just fine. I guess my Pro-95 is toast for using as a source for trunk88.

 

[gmclam]

I have one of each (PRO-92 & PRO-95) that I can use the discriminator outputs from. The signal levels from the radios could be different, be sure to adjust the input signal level on your computer. Some sound cards work better if you have a coupling capacitor on the scanner output. One of my scanners works better when I connect it to the MIC input on a sound card, the other scanner works better when connected to the LINE input. I use a digital level meter to make sure levels are ideal to whatever decoding software I am running.

 

[W2PMX]

I guess my Pro-95 is toast for using as a source for trunk88.

If the discriminator itself (or some other part of the scanner) is bad, you won't be able to hear a clean signal in the speaker - even on a close clean signal. If you can, redo the tap with new components. (The audio from the tap point is the audio you hear in the speaker after some filtering and amplification.)

 

[Spadinator]

If the discriminator itself (or some other part of the scanner) is bad, you won't be able to hear a clean signal in the speaker - even on a close clean signal. If you can, redo the tap with new components. (The audio from the tap point is the audio you hear in the speaker after some filtering and amplification.)

I will try that....I can still hear the signal through the speaker, but for some reason the signal is weak through the tap. Should I attach the 10K resistor like is done on other scanner taps?

 

[ka3jjz]

Actually if you tap the discriminator, that's before the audio amp chain, not after it...Mike

 

[Comint]

. . . Should I attach the 10K resistor like is done on other scanner taps?

The main purpose of the 10K resistor is to provide some isolation between the discriminator chip and the outside world, so that if accidently short the audio lead to earth/chassis, you won't damage the discriminator chip.

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Comint

 

[gmclam]

I am NOT using any resistors on the discriminator output of my scanners (including PRO-95) and not had a problem. I can't imagine a scenario where someone is shorting out that signal as long as you use regular audio cables and only connect/disconnect them with the power off.

 

[W2PMX]

I am NOT using any resistors on the discriminator output of my scanners (including PRO-95) and not had a problem. I can't imagine a scenario where someone is shorting out that signal as long as you use regular audio cables and only connect/disconnect them with the power off.

If you're doing IF filtering (a 2-4pf cap after the resistor), it won;t work without the resistor. (The short-protection is just a bonus.) Whether you need to filter the IF depends on where you're sending the discriminator audio (a slicer or a computer sound card) and whether the particular scanner bleeds IF into the discriminator output. Without a scope (even a cheap old one) you have no way of knowing what the signal looks like.

Mike, that's what I said - the speaker is "after some filtering and amplification".

 

[gmclam]

PRO-95 discriminator output

I'm not doing any filtering. The signal directly from the discriminator looks good. Sorry I don't have a scope capture to post. I am just running the signal into a PC sound input. I've used several different computers & sound cards including the $1 USB cards I got from eBay.