Unitrunker and LTR Systems

[Saint]

Any information when Unitrunker will be able to listen in on LTR Standard systems and collect the information.
Steve

 

[SCPD]

The problems with LTR through a sound input are ...

1. the coupling capacitors built into your computer distort the waveform of the low speed data pulses.
2. any speech must be filtered out.

Edge triggered logic will help with #1 but is less than ideal. Low pass filtering in software for #2 is expensive in terms of CPU cycles.

Some of the Opto and Optocom radios provide a raw LTR frame data dump over the serial port so that is one way to deal with #1 and #2. A few other radios provide direct USB audio which would at least provide a way around #1.

One other solution is an advanced slicer circuit that - so far - no one has produced as of yet. The closest to what I have in mind is the circuit proposed by wb1hbu (Eric) with tweaks by pro92b (Bill).

As you can see, this is still in an R&D stage. I don't want to put something out there that is hard to set up or produces crappy results.

 

[Saint]

Ltr Software

The problems with LTR through a sound input are ...

1. the coupling capacitors built into your computer distort the waveform of the low speed data pulses.
2. any speech must be filtered out.

Edge triggered logic will help with #1 but is less than ideal. Low pass filtering in software for #2 is expensive in terms of CPU cycles.

Some of the Opto and Optocom radios provide a raw LTR frame data dump over the serial port so that is one way to deal with #1 and #2. A few other radios provide direct USB audio which would at least provide a way around #1.

One other solution is an advanced slicer circuit that - so far - no one has produced as of yet. The closest to what I have in mind is the circuit proposed by wb1hbu (Eric) with tweaks by pro92b (Bill).

As you can see, this is still in an R&D stage. I don't want to put something out there that is hard to set up or produces crappy results.

Thanks for all the information on this subject, I was not aware of all the issues that have to be overcome to decode LTR Systems, I do agree that it would not be of any use to the public to release something that is not going to work and confuse and frustrate people because it's not feasible and has to many bugs in the program, again thanks for the information.
Steve