996P2 Multiple Sites

I am trunking a Statewide system and am seeking help for the 2 scenarios below.

Scenario #1 When trunking with only 1 tower programmed I tend to miss the first second or so of the initial transmissions. My RS scanners and my BCT15X consistently lock on the talkgroup and unmute much quicker. Any way to speed this up?

Scenario #2 If I program multiple tower sites (all on my statewide MSWIN system) the scanner takes a long time to scan each of the 5 bordering tower sites even though there is no or little traffic on them. I suspect this is because of an extremely week signal on the control channel. Most of the traffic is on my local tower site but I like to scan the sites 20-30 miles away to search for any new talkgroups that may not be in the RR database. Below is a link to a quick video showing the slowness to scan between sites. https://www.youtube.com/watch?v=OTOnq2EDTDQ

One tip someone gave, was to set the squelch to 2.

Do you have an enormous amount of talk-groups?

Think there are about 200 talkgroups programmed currently as my county is fairly large. The squelch is turned all the way down as this is a P25 phase 2 system, I didn't think the squelch played a part in trunked systems.

kf5bti said:

Think there are about 200 talkgroups programmed currently as my county is fairly large. The squelch is turned all the way down as this is a P25 phase 2 system, I didn't think the squelch played a part in trunked systems.

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That's not too many. Regarding the squelch, that's been my understanding also, with P25 systems. However, it was mentioned in another thread, where the guy claimed it did speed things up. I set mine at 2, and honestly didn't notice a difference, but it doesn't hurt to try.

The weak signal could definitely be the cause. I'm a little confused by your post, as this being a P25 system, how are you receiving it on your BCT15X as well?

My initial post was a little confusing....In the comparison in scenario #1 is comparing a Motorola II system not the P25 system.

iMONITOR said:

That's not too many. Regarding the squelch, that's been my understanding also, with P25 systems. However, it was mentioned in another thread, where the guy claimed it did speed things up. I set mine at 2, and honestly didn't notice a difference, but it doesn't hurt to try.

The weak signal could definitely be the cause. I'm a little confused by your post, as this being a P25 system, how are you receiving it on your BCT15X as well?

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The number of TG's have zero effect on scan sped. Squelch would not - if they were all decent signals. on weak sites I'd think they might/

phask said:

The number of TG's have zero effect on scan sped. Squelch would not - if they were all decent signals. on weak sites I'd think they might/

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Even when in talk-group I.D. scan mode?

iMONITOR said:

Even when in talk-group I.D. scan mode?

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Yes

phask said:

Yes

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Thanks, good to know. There's always more to learn her on Radio Reference!

Only analog channels would slow down the scan speed.

Scenario 2:
If I remember correctly, the scanner spends about 2-3 seconds monitoring the control channel for each site it hears. Its a design thing and there is nothing you can do to reduce or increase the time a scanner dwells on the control channel.

Thus if a channel grant (transmission on desired talkgroup) occurs on Site B while your scanner is monitoring Site A's control channel, you could miss up to that first 2 seconds.

Also if you are in an area where you can receive multiple sites (in your example 5) its possible you will miss traffic. That's because 8 seconds (4 towers times 2 seconds per tower) involved with checking the 4 other towers before the scanner gets to the one carrying your desired transmission.

It's a balancing or trade off thing. Do you want to hear a wide variety of traffic, then use as many sites as your scanner can "hear" (in range of). The cost is missing something you think is of greater importance. If your listening preferences are for certain talkgroups, then only select the site/tower that the Talkgroup uses as it's "Home" site.

Scenario 1:
You might try tinkering with the P25 Adjust Mode or P25 Adjust Levels. I believe it's a case of how fast the scanner "latches on to" or starts decoding the P25 data. One scanner may be doing this a little faster than the other because of default values.

Nasby said:

Only analog channels would slow down the scan speed.

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Not exactly (but close). Each site has "very generally speaking" on average of at least 4 control channel frequencies. The scanner will look at each control channel frequency for control channel activity. If activity is detected, then it monitors the frequency as I described above. If activity is not detected, the scanner jumps to the next frequency and so on.

Thus if you have 10 sites programmed, its possible that the scanner has at least 40 frequencies it will listen to.

This situation is greatly magnified for a statewide system having 100 plus sites. That's 400 frequencies to check.

Then if you have an x36 or Home Patrol scanner, all frequencies are programmed and not just those marked as control channels. So now you are looking at around a 1,000 frequencies.

So at the upper end, you could lose almost a second depending on the system, type of scanner and whether location control is involved.

Slowness to scan between sites may be a long hold time. Check your hold time for each site. I keep mine at 2 seconds or less, but like someone else said if you have a good signal on a site it will still hold for about 2 second regardless if there is a transmission. With no signal strength it should move along right away.