Scanning speed

[Ncfirewire]

I currently own a 436 & 536 bcd and basically only monitor 1 p25 digital trunking system that has about 40 talk groups. If i remove about 20 talk groups will it scan the others quicker or doesn't it matter??

thanks

 

[jonwienke]

Removing talkgroups from a trunked system will not significantly increase scan speed. It simply skips transmissions from those talkgroups so the radio doesn't waste time playing traffic you don't want to hear. But if there is no traffic on those talkgroups, there's no difference one way or the other.

 

[fenderblue]

Question if it is analog----??

 

[ofd8001]

"Scanning" a trunked radio system, be it digital or analog is much different than scanning a conventional system. With a conventional system, the scanner checks each frequency for activity. If there is activity, then the scanner remains on the frequency.

With a trunked system, the scanner monitors the control channel for grants. The scanner gets information from the control channel whenever a grant occurs, including TGID information. Next the scanner looks at programmed talkgroups to see if the "granted" TGID is present and not locked-out. If there is a match, the scanner does "its thing" and the communication is monitored.

In other words, a trunked radio system does not listen to each talkgroup to see if it is active.

Thus there is nothing to be improved scan speed wise by reducing the number of talkgroups. A trunked system with 1 talkgroup will scan just as fast as one with 1,000 talkgroups.

(That being said, a trunked system with multiple sites is another story. The scanner dwells on each site for about 1.5 to 2 seconds, monitoring the control channel for grants. I don't think the OP is describing this type of system, but thought I'd mention it.)

 

[marksmith]

The above is exactly right for when the radio is scanning. 1 or 1000 talkgroups scan at same speed.

The difference comes with when it hits on a talkgroup. It will stay with that talkgroup basically until things are over... or until there is a sigificant enough gap in comms to resume scanning.

If you have enough talkgroups you are not interested in, such that they tie things up so you miss transmissions on the talkgroups you are interested in... now we have a different question .

Eliminating or locking out uninterested talkgroups will definitely improve your likelyhood of hearing comms on your talkgroups of interest.

This is especially true if the 20 you want to lock out are transmission hogs that are constantly active, and the 20 you want to monitor are less active.

Mark
WS1095/536/436/996P2/HP1e/HP2e/996XT/325P2/396XT/PRO668/PSR800/PRO652

 

[marksmith]

Question if it is analog----??

Digital or analog is no difference, as long as the system is trunked, it works the same way.

Mark
WS1095/536/436/996P2/HP1e/HP2e/996XT/325P2/396XT/PRO668/PSR800/PRO652

 

[ofd8001]

A question for the OP: These scanners have no way of indicating scanning speed on trunked systems. With only conventional frequencies, you can somewhat see the scanner progress through the frequencies.

So on your trunked system, if you are looking at it and wondering why it lingers on the trunked system with no activity, before moving on to other systems, here is a little explanation. The scanner spends about 1.5 to 2 seconds on each site monitoring the control channel for active transmissions. There isn't anything you can do to shorten this because of the "mechanics" on how the scanner does its thing. While you can't decrease that minimum time, you can increase the "linger time" by setting the Hold time for a given site.

 

[jonwienke]

The minimum trunked system site hold time is dictated by the data being broadcast on the control channel.