Slicer quit working

[DaveNF2G]

My LTR trunktracking setup no longer decodes any LTR signals. It behaves as if the signal is not present.

The software (LTRTrunker) and the serial port appear to be functioning because when I start it up the voice receiver is directed to its standby frequency.

Is anyone aware of a reason why a powered low-pass LTR slicer would suddenly stop providing audio to the serial port? Power is still present and all of the physical connections are solid. Presence of the usual radio signal has also been verified with multiple receivers. Same failure occurs no matter which tapped receiver I use.

 

[slicerwizard]

You should:

a) put SLICER.EXE to work

b) use your PC's sound input and a scope program to show you what the audio looks like at the various stages in the slicer circuit

c) if you have a DC voltmeter, take some readings (power, for starters)

 

[DaveNF2G]

The problem seems to be the slicer.

I have tried the following tests with multiple scanners and computers.

Power to the slicer is OK.
Signal is present from discriminator tap (BC-235xlt and PRO-96).
Serial port functioning properly (IBM 755C Thinkpad and Dell Latitude CPi).

With any combination of the above equipment, when I set the scanner on a local LTR-MultiNet "control" channel that I have been tracking with the exact same equipment for a couple of years, and then run SLICER.EXE, I see no activity on the serial port at first, then suddenly (without my touching anything) the port will become active with interrupts. This can begin anywhere from a few seconds to several minutes after startup.

After verifying comport activity with SLICER.EXE, I then switch to LTRTrunker. The program immediately takes control of my voice scanner and sends it to the TRACKSCANPARK frequency. Sometimes the program decodes the signal and starts tracking the system, but usually it does not. I get no activity whatsoever on any other kind of LTR system (regular or PassPort) any more, either.

So, I conclude that my slicer has developed an intermittent fault of some kind.

I can either try to build one or hope that UniTrunker includes LTR protocols very soon.

 

[inigo88]

Hi Dave,

Try running windows in Safe Mode, or booting in MS-DOS (not a command line window).

I built the slicer and had little to no SLICER.EXE activity no matter what I tried. After going through everything with a continuity tester with no obvious problems and being totally stumped, I read online that some RS-232 serial port driven programs can conflict with software drivers on your computer (usually when more than one piece of software is trying to access the port at once), and to boot in MS-DOS to be absolutely sure. Not being savvy enough to do so, I crossed my fingers and hoped Windows Safe Mode would suffice, and it did!

If that doesn't work, I would be much more convinced that the problem lies in the slicer hardware.

I also agree that there is high demand for a windows sound card input Passport & Multinet program(s). While I have yet to run into any Multinet, Passport is significantly popular here on the west coast. Realistically we just need to make the first part (sound card low-pass filtering and decoding) of Slicerwizard's LTR-Analyzer talk to the second part (database of multinet & passport OSW commands and trunker style interface) of Eric Cottrel's LTR Dump/LTR Trunk programs and then make it all run on Windows XP and Vista! Ideally a new program could be created from scratch.

I had a blast a year or so ago posting on the forums here about trying to identify lesser-known Passport OSWs (unsupported by Eric's programs) taken from my LTR Dump log file. As much as I want to learn C++ and I would love the excuse to try and make a working program for this, I wouldn't know where to start and would be way out of my league ("Take an audio signal, filter out everything above a specified frequency and then chop it into bits of data" isn't exactly the title of a chapter in one of those 'Teach yourself a programming language' books!).

To you few guys with the necessary electrical engineering and computer science knowledge to do it, let us mere mortals know if there's anything we can do to convince you to take on the project - be it financial donations or just channeling large quantities of good will in your direction.

Regards,

Inigo

 

[DaveNF2G]

I guess I should have mentioned that I run the legacy *Trunker software under MS-DOS exclusively. Windows is not even installed on either of the notebooks that I use for that purpose.

 

[Bill_White]

What pin is the output of your slicer?
Did you by chance change TRACKSLICERPIN=xxx, in trkenv.bat, to another pin?
Pin xxx of the DB9 =
1 = DCD
6 = DSR
8 = CTS

 

[DaveNF2G]

No. Absolutely no changes have been made. The station suddenly quit working.

Also, as mentioned above, decoding does occur intermittently. This would not be possible if the wrong pin was specified in trackenv.

I'm not stupid.