Interesting Site 40 info

[plaws]

If you had a scanner that didn't track trunking systems and you wanted to listen to the Norman site, what would you do? Well, the old advice was to put in all the channels and lockout the active control channel and make sure delay is disabled.

Well that might be wrong.

I reset the counters on Unitrunker this morning and have been monitoring Site 40 since, oh, say 1000 hours. Now, Site 40 has the following channels:

854.78750
855.21250
856.76250 Y
856.96250 X
857.76250
857.96250 X
858.76250
858.96250 X
859.76250* Y
859.96250*
860.76250*
860.96250*
866.31250
868.90000

That's a lot of channels. But guess what? If you only entered only the channels with the Xs, you'd hear over 90% of the traffic. If you added the ones with the Ys, you'd be at nearly 100%.

What happened to the spectrum efficiency of trunking systems?

 

[car2back]

I'm no trunking guru but...

Is it possible the controller assigns voice channels in a specific order and when there is not a high amount of traffic some channels don't see usage?

Example:

Your business has 5 phone lines. Calls coming in and going are assigned a line in numeric order, 1-2-3-4-5. 1, 2, and 3 may see higher usage since in order for line 5 to be used there must be 4 other people using the phone.

 

[KE5EHI]

I think you would see the same thing with Tulsa's system. It seems late at night I see the same few frequencies on most transmissions. I would agree it probably has a set order for the freqs and just takes the next one, so the first 4 are the most common.

 

[robynsjw]

From listening to Edmond's site this way before investing in a trunk tracker, it seems like the "active" channels would change daily, or every few days. I assumed this was to keep any 1 transmitter from getting a lot more use than any other. Total transmit time could probably be included in that decision.