Q: DIU300, Centracom Elite- Logging Recoder Audio

[commstar]

Hello, My question surrounds the optimal point within a radio system to obtain nice clean high-quality audio, as close as possible to what a field user would experience; Audio suitable for use in a logging recorder, suitable for all uses including legal diligence. In other words, the best available.

Customer is using Centracom Elite, CEB/cards into DIU3000's then outbound. Conventional repeated system, mixed modes in the system currently on various channels (P25/analog).

Customer is currently experiencing numerous poor quality, unprocessed audio with T1R1 signaling/keying tones present and crosstalk multiple channels recording on a logging recorder when there is only voice channel with traffic. Beleived not to be RF related but due to input signal quality. Phone quality is great, radio not so much so the recorder is not in question at this point absent additional evidence to the contrary.

I understand that 4-wire can be adapted to 2-wire audio and brought down to the Logger and this would be optimal audio.

My ear tells me is that the current audio source is poor there is better audio available in this system- can someone please take a moment to enlighten me where one would obtain such processed audio in a similar system?

Any rules of thumb on where to get this audio? Obviously, I am not the tech but am trying to work thru this problem for the best solution.

Thanks-in-advance and all guidance appreciated.

[wavetar]

You didn't mention where the current point of audio logging was taking place. Traditionally, Motorola recommends using LOMI/LORI combos in the CEB to bring the desired resources out to bix blocks. Audio obtained through this method is as you would hear it at the console...clear with no extraneous tones & whatnot. Requires extra boards ($$$) and changes made to the CDM database ($$$ depending on who does it).

There is also a mic & 'select' audio logging pair provided on the rear of each CIE if you wanted to log each OP individually. A lot less hardware required, and no CDM changes required, however you don't get the benefit of logging 'unselect' audio in this configuration. For one customer we tapped off the unselect speaker to provide an audio pair for unselect audio, and changed the Elite config files to always have the desired resources set to a particular volume level...and of course the unselect speaker had to remain turned up to a degree.

[chartofmaryland]

The product your describing is one with this request already built in.

From the CEB there is a logging line available from the BIM for each radio resource.

If you have the jack panel with multiple RJ45's then the mating 25 pair cable would need to be run to a punch box where you can tie into this for the audio. If you have the audio already routed to punch blocks the audio can be found on the third pair down on every radio resource set.

This is the best option while doing it all from the CEB.

It can get more complicated, but then you would need to include many other pieces of hardware to make everything work.


CoM

[d119]

If the CEB breaks out in to RJ21X blocks (punchblocks), the clean, clear logging audio should be available right above or below the 4-wire DIU connection back to the BIM. Depends where the BIM is in the CEB cage.