What Gets Scanned, When, Question

[BOBRR]

Hello,

Trying to understand a bit more re the mechanics of how the unit functions.

Let’s say a have a few FAV lists loaded via Sentinel on my BCD 436.

I have the Range selected as, e.g., 20 miles, and my zip code,
all previously entered.

I now turn the unit on.

What actually happens:

I assume the unit first scans the U.S. Database fully, or does it,
somehow, know which of all of its entries are within 20 miles of my zip code,
and only (repeatedly) scan only these few ?

How does it determine this ?

After a single scan of the full U.S. Database, does it then do
all of the FAV lists I had entered previously ?

Again, the full FAV list, or does it know which entries in it
are within 20 miles ?

Would just like to learn the mechanics of what actually happens when one turns
the unit on and it begins scanning better than I realize I do now.

Can anyone explain this, please ?

Thanks,
B.

 

[jonwienke]

First, RTFM, specifically the sections about Location Control. And this:

How it Works: Location, Location, Location

The scanner never scans the entire North America database, only the portions that are within range of your location (which you must specify by entering your postal code, connecting a GPS puck, or manually entering your latitude and longitude) and match the Service Types you enable in the scanner menu.

You toggle the main database and individual favorite lists on and off in the scanner menu.

When you create a Favorite List, you can choose whether to enable Location Control for that list. If the list only contains nationwide frequencies such as CB, marine, FRS, GMRS, MURS, etc., you can leave Location Control off, and when you enable scanning of the list, the list will be scanned regardless of location as long as you have the appropriate Service Types selected for scan.

But in most cases, you will want to enable Location Control so you're not wasting time scanning stuff that is out of range.

A 20 mile Range setting is probably wrong. The Range setting is added to the range parameter for an item in the database. So if a fire department is listed in the database as having a 20-mile service area surrounding its geographic location, and you set a 20-mile Range, you will start scanning that fire department when you are 40 miles away. In most cases, if you set Range to more than 10 miles, you will be scanning a lot of channels that are too weak to receive unless you live on a mountaintop and have a good outdoor antenna.

 

[ofd8001]

Typically I scan only Favorites Lists while in my home area or a trip destination and leave the full database off. If I'm traveling, then Favorites are off and the full database is on. I have a GPS device in my vehicle which sends location information to the scanner, so it will Load and turn off/on things as appropriate.

Scanning both the full database and Favorites Lists is duplicate scanning.

 

[sparklehorse]

I program my radios similar to ofd8001. I NEVER scan the database when at home, or use location based anything. Those methods tend to scan a lot of stuff you're not actually interested in, or can't receive anyway. This slows your scan cycle way down, causing you to miss a lot. I know where I'm located. I know what I can reasonably receive from here. I build my favorites lists based on that knowledge. That way I'm scanning only what I can hear, and want to hear. When I travel around my state I use a GPS puck and scan only the Favorites Lists I've created for the areas I'm traveling through. Again, this way I scan exactly what I want to scan, and nothing more. I also check, and if needed edit the location data for each trunk site, and each agency, as the location data in the RR database is full of inaccurate location data.

.