BCD396 reception of ASTRO 9600 system

[qball]

I have a 396 and cannot get decent audio from the local Motorola 800MHz 9600 baud simulcast trunked system. I have tried everything in the owner's manual to fine tune the digital audio to no avail.

Does anyone else have experience monitoring a similar system and having crummy RX audio? Any suggestions on how to better tune the audio settings?

I have the latest firmware. I have perfect signal strength. I have tried the attenuator. I have confirmed that the talk groups are not encrypted.

I am not sure what to do....any help is appreciated!

Thanks!

 

[iMONITOR]

That's been an issue for many of us in Michigan as well. Michigan has a few simulcast systems, and the Uniden scanners have difficulty handling the CQPSK (Compatible Quadrature Phase-Shift Keying) modulation.

Some have cleared things up a little buy using a hi-gain Yagi antenna, pointed toward only one of the several antennas used in the simulcast sub-system. I'm right in the middle of the Macomb County simulcast system in Michigan. I was able to improve things by using a dual-band (144/440) antenna, to desensitize the radio on the 850MHz band.

It appears (at least for now), that Radio Shack's (GRE manufactured) PRO-96, and PRO-2096 are able to cope better with these simulcast systems due to better handling of CQPSK.

 

[qball]

GreatLakes...Thanks! I have a GRE PRO96 that is doing about the same thing. I have tried a step attenuator on it and haven't gotten the results that I want, either.

I guess that I will try the directional antenna next.

 

[iMONITOR]

GreatLakes...Thanks! I have a GRE PRO96 that is doing about the same thing. I have tried a step attenuator on it and haven't gotten the results that I want, either.

I guess that I will try the directional antenna next.

Make sure you have the more recent version of the DSP firmware in your PRO-96. To check it, turn the scanner OFF, then turn it ON, and quickly while the "Welcome..." screen is displayed, press the number 3 key. Check the DSP version. The most recent is v 1.3 I believe. Let us know what your have. If you need to upgrade we'll go from there.

 

[qball]

I had the 1.3 firmware in the GRE and recently reverted to the 1.2 to see if it worked any better. Well, it is about the same. I may go back to 1.3 and try the step attenuator again.

 

[iMONITOR]

Do you know how many sites make up your simulcast system? Where are you located in relation to them?

 

[qball]

there are 8 of them and I am 1.5 air miles from one at home and the next closest is 4 miles. At work....about 5 and 10.

 

[rmquinn3419]

I have a 396 and I live around 4 miles from the closest tower and the next closest tower is about 6 miles from the new York County SC System, and i seem to have no problems receiving traffic with the 396 other than having to be in the right spot the avoid it cutting out, but other than that i receive it perfectly clear, I also have the latest firmware installed.

rmquinn3419

 

[iMONITOR]

there are 8 of them and I am 1.5 air miles from one at home and the next closest is 4 miles. At work....about 5 and 10.

I think that's part of the problem. On a simulcast subsystem, all the tower sites are transmitting the same thing, at the same time, on the same frequency. I think a directional antenna (not necessarily high gain), pointed at the closest site might help. Because most directional antennas do have some gain, it may be necessary to either use the attenuator setting in the radio, or use an in-line attenuator.

 

[red8]

That is strange, because I do not have that problem with my 396. I have noticed the audio is tad bit louder on digital than analog.
red8

 

[iMONITOR]

That is strange, because I do not have that problem with my 396. I have noticed the audio is tad bit louder on digital than analog.
red8

Does your area have a simulcast sub system?

It has a lot to do with how the towers are laid out, where you are located in relation to all the towers, how much power each tower is outputting, what direction the antennas are optimized for, etc.

Do you travel in your area and continue to get good reception all around the area?