Missing some P25p1 traffic

[Syncopations]

So my local agency recently switch to P25 trunking(10/3/2017). I've already "captured" a few talkgroups and have them properly programmed into my x36 line of scanners. I also have a Harris P7200 with P25 trunking programmed with the same information. My issue....

When a unit or dispatch unkeys the radio, I may miss the beginning part of the next transmission on the scanner. But on the P7200, it doesn't miss anything on whatever talkgroup I'm on. Is this an issue or am I doing(or programmed) something wrong? I do have a 2 second delay, but it doesn't seem to help.

Also, it's a single site. No simulcast or other towers.

Thank you.

 

[troymail]

Could be many things but here is something to try:

Set the system "HOLD time" to something other than 0 (I think 255 is the max). See if that makes any difference.

Easier to Read BCD436/536HP Digital Scanner Manual

This is just a test - you probably wouldn't want to do this if you are scanning more than that single system....

 

[SCPD]

Could be many things but here is something to try:

Set the system "HOLD time" to something other than 0 (I think 255 is the max). See if that makes any difference.

Easier to Read BCD436/536HP Digital Scanner Manual

This is just a test - you probably wouldn't want to do this if you are scanning more than that single system....

Had the same issue lower delay to 1 or 0 and set hold time to 2 seconds...

 

[jonwienke]

If the system you programmed allows you to change the Digital Wait Time parameter, set it to zero milliseconds. Any value other than zero will cut off that much from the beginning of each transmission. This is not applicable if you cannot edit Digital Wait Time.

Does the problem occur if you are manually holding on the system? If you're only monitoring the one system (whether it's the only thing in your active Favorite List or you are manually holding on it with the System Hold button), the system hold time is irrelevant. It's only used to hold the scanner on that system for a minimum length of time before moving on to the next system when scanning multiple systems.

Setting Delay to 0 is a bad idea, because it guarantees that the scanner will resume scanning as soon as the unit unkeys. If you want to catch all of a reply transmission, delay should be set to 2-5 seconds to increase the probability the reply will start before the scanner resumes scanning.

Try setting a manual site threshold. To get an idea of what it should be set to, press scroll, function, scroll, and the scanner will show decode error rate and what threshold it is using while decoding traffic from the site. Start with the value you see most when you are receiving traffic with a low decode error rate.

Also, make sure you don't have any Priority scanning turned on (priority channels, close call, or weather). That can cause dropouts in transmissions.

 

[Syncopations]

So I programmed the 436 and the 536 using an identical profile, with 2 second delays. It appears that the 436 drops the channel at the end of the transmission, thus letting it pick up the response traffic. However, the 536 holds on to the channel at the end of the transmission for approximately 4 seconds, then releases the channel, causing it to miss the response traffic. They have the same profile, with the same settings. I'm thinking it's hardware related. Thoughts?

 

[jonwienke]

What firmware are they running?

 

[Syncopations]

What firmware are they running?

Both are running 1.11.31.

 

[Ubbe]

It's a firmware change and make wonders with DMR sites. Catches whole conversations much better with trunked DMR systems. I don't know anything about P25 but I guess the system sends out a flag that the conversation have left the channel and radio should go back to control channel, and the scanner should do the same. There's no end tone configuration in P25 or other parameter that you have missed?

/Ubbe

 

[jonwienke]

I'm skeptical that the configuration is EXACTLY the same. I suspect one radio is monitoring a system in a favorite list, and the other one is monitoring the same system in the main database, and there is some config difference between the DB and the FL.

 

[Syncopations]

Here is a video link showing the issue I’m having.

Both scanners have the exact same profile from Sentinel. Both radios were cleared(reset) and reloaded. Both running the most current firmware with both paid upgrades.

https://youtu.be/ycgTYAb5Vso

 

[jonwienke]

Run the same test with the P25 decode error and threshold levels display active.

Also, where is the audio coming from? When I have 2 scanners monitoring P25 or any digital format, there is always a slight delay between one and the other due to decoding latency. I don't hear that in your clip. Which scanner is actually being heard?

 

[phask]

Jon - I'm running 1 536,996P2, and HP2 - all audio is in sync. But a 996x,780 or HP1 is behind. Different vocoders...

- just on one P25 system, so YMMV -

 

[phallout2000]

same issue with hp436 using p25

So my local agency recently switch to P25 trunking(10/3/2017). I've already "captured" a few talkgroups and have them properly programmed into my x36 line of scanners. I also have a Harris P7200 with P25 trunking programmed with the same information. My issue....

When a unit or dispatch unkeys the radio, I may miss the beginning part of the next transmission on the scanner. But on the P7200, it doesn't miss anything on whatever talkgroup I'm on. Is this an issue or am I doing(or programmed) something wrong? I do have a 2 second delay, but it doesn't seem to help.

Also, it's a single site. No simulcast or other towers.

Thank you.

has there been a consensus on what the solution to this is? my radio cuts out in the middle of transmission, then resumes. i also miss a lot of replies. but it seems that every 2-3 seconds there is 1 second of silence.

 

[jonwienke]

You probably have a Priority turned on--priority channel, close call, or weather.