LAPD audio cutting off on BCD436HP

[SuperHotLarry]

Howdy Howdy! I'm having a little bit of an issue with listening in to LAPD on the BCD436HP. When listening to their audio (from the latest database), I hear the dispatch/tac audio clearly, except that the last half-second of the transmission always seems to be cut off.

I've tried different antennas, I've tried fiddling with the AGC, digital hold times, digital threshold, digital threshold times and nothing seems to be solving the issue. I've also tried different antennas and I've been all over the city to see if it was because of a lack of signal, but the issue continued whilst driving around the city.

At first, I believed it to be an issue with the P25 decoding, but all other P25 broadcasts I've tested don't seem to have this issue.

My question: is this a classic case of "the issue is between the driver's seat and the steering wheel?" Or is there some sort of setting I'm missing? Has anyone else had this issue?

Thanks!
-SHL

 

[doctordialtone]

.

My question: is this a classic case of "the issue is between the driver's seat and the steering wheel?" Or is there some sort of setting I'm missing? Has anyone else had this issue?

Thanks!
-SHL

I assume you've ruled out the obvious suspects, such as Priority and Close Call modes?

Look closely at the display while it's happening for a clue.

Priority Modes

 

[Ubbe]

I hear the dispatch/tac audio clearly, except that the last half-second of the transmission always seems to be cut off.

I've had that in a system and was coming from the patch electronics between a new digital and an old legacy analog system. The indication of when someone stop transmitting on the legacy system, the squelch close, are done thru optocouplers that are instant, but the audio has to be converted between analog to digital that always has a delay component. When the indicator for squelch indicate that the legacy transmission has ended, all the audio hasn't been transmitted yet in the digital system and are cut short. I added a diode and a capacitor to make the optocoupler hold on to the signal for 1 sec.

Check what site/system you are monitoring. Perhaps you will need to monitor another site or system to get rid of the problem. My Whistler TRX-2's audio recordings suffer from the same problem, that the recordings start/stop are instant but the audio are delayed creating a noise burst at each recordings start, the carriers audio aren't present yet, and the last syllable are cut, for systems using analog signals with no subtones.

If there's a scanner setting problem I can only think of if NAC's are used, that it somehow drops that prematurely in the transmission. Try setting it to ignore or search, if they are used in that system.

/Ubbe

 

[SuperHotLarry]

I assume you've ruled out the obvious suspects, such as Priority and Close Call modes?

Look closely at the display while it's happening for a clue.

Priority Modes

Yep. No priority set and Close Call is not set up. Very strange

 

[nokoa3116]

Could it be your squelch, what if you set it lower? Uniden is sometimes annoying with this. I have only monitored LAPD for a few days using a Motorola XTS. I don't remember if this is like a normal thing for these conventional systems or not.