I had noticed the same in Southeast Tennessee. Placing the 436HP alongside an aging Pro106, it was obvious that the 436HP was missing a lot of calls. When I originally set up my 436HP, I simply cut and pasted the stuff I needed from TACN in the database. The database contains the control channels and voice channels. Like most trunking scanners, the 436 does not need the voice channels. Get rid of them, and you might consider even getting rid of the alternate control channels. This greatly increased the speed of my 436. You can go online to the Radioreference frequency database to quickly identify the control channels. I would suggest leaving your existing TACN favorites list(s) as they are, and creating a new favorites list for this experiment, which will allow you to switch back and forth to compare performance. I have found that TACN in this area rarely changes control channels. If you are worried about missing calls due to changed control channels, then create a new conventional favorites list containing all of you usually active TACN control channels. That will allow you to do a very quick check each morning for any missing, and possibly changed, control channels.
I'm not sure why this works, but I think the 436 is probably checking each programmed channel for data. Getting rid of the voice channels prevents this waste of time.
This is sorta my Step 1 for speeding up the 436HP. Let me know if I helps. If it does, I'll post Step 2, which gets a bit more complicated.
