BCD396XT/BCD996XT: GPS Question

[wb4ifo]

I am adding a GPS to my BCD996XT. The number of sites in my scan list will be in the hundreds. The GPS can be 'programmed' to supply its updates every second, or go several seconds before it sends its information.
Does anyone have experience using a GPS with a large scan list?
I realize that each time the GPS sends an update, the scanner recalculates the distances to each of its sites and updates the list of 'locked out' sites. Only then can it 'scan'.
What I don't know is whether this process is so complex or time consuming that the scanner won't have time to complete its scans before it receives the next GPS update.
In short, I don't want to overload the scanner with GPS info, if that is even possible.
Is the process so fast that there is no problem with this?

Or is this something that will cause a problem?

Thanks,
Fred

 

[jonwienke]

You're overthinking this. Normal GPS scanning with the x36 line involves the entire US-Canada database, and the scanner has no trouble even though there are tens of thousands of channels in the database. The trick is that the scanner doesn't recalculate every time it receives a position fix (several times per second), it waits until a certain minimum time or distance from the last recalc has occurred. And even with a large multinational database, it only takes a second or so to update what is turned on and off.

Any favorite list you've created is trivial in comparison. Just use GPS and don't worry about it.

 

[marksmith]

The previous post is accurate.

Also, with a 996xt you will need to make sure that position data is in all your system and frequency data. Otherwise gps does nothing.

536/436/ws1095/996p2/996xt/325p2/396xt/psr800/396t/HP-1/HP-2 & others

 

[datainmotion]

The 996XT, does in fact, have issues with large databases and site switching of them via GPS. Paul Optiz from Uniden has cautioned about this in a number of posts. I have seen it first hand with my 996XT where I may be 5 or more miles (depending on speed) within my pre-defined range for a given site, before the scanner switches on that site. Its all about processor usage, from what I understand.
In short, your best bet is to break down the database in to smaller groups (I do mine following CO SP District boundaries) and assign each of those a separate QK. If you do, then you can switch off areas you are not in or near, saving the scanner the processor usage.

For reference, here is one of the first threads regarding this situation: https://forums.radioreference.com/u...996xt-gps-system-lock-unlock-performance.html

 

[ofd8001]

Before I upgraded to the x36 scanners, I used both the 996XT and 396XT with GPS devices for some multi-state trips. For example Kentucky to North Dakota.

It did seem like the scanner did spend a lot of time (several minutes) "processing" what should be on or off during power-up. As I travelled along it wasn't too lengthy, however.

Still I figured I'd "help" the scanner/GPS by assigned System Quick Keys based on states. As I entered a given state (Indiana for example) I'd turn the state's SQK on and the state I was leaving SQK off.

Thus I was doing was similar to what the previous poster suggested. I was happy with the performance.

 

[eaf1956]

The x36 line is much better with the GPS switching than the x96 line was. At least that was how it worked with my 996XT before I changed to a 536HP.

 

[wb4ifo]

It sounds like the scanner will have a longer start up time, but will handle the process better than I expected. Once it's past the rather list of 'lock outs' from startup, the design is so that it minimizes impact to the mobile user. It also appears that I will have to assign gps locations to all of the conventional sites unless I want them 'all' scanned along with the non-locked out sites. GPS locs are already provided for the large, state wide, networks I wanted to monitor. I will now have to arbritarily assign a loc for a county or city system. That will be fun.
Thank you everyone for your information on this. It sounds like I was over-thinking the problem.
I got some nice, but cheap, gps modules a year ago and will now use them.

Thanks again,
Fred

 

[N9JIG]

When I lived in Illinois for my 996XT I built up a pretty extensive set of Systems for StarCom21, the Indiana and Michigan systems as well as the many counties in Wisconsin (before WisCom). All in all I had 130 or so sites plus 102 separate county systems in Illinois and close to that amount for MI, IN and WI. Alll these sites had a center point and range set up.

At times if I was in a poor GPS locale the radio would take a while to find it's way and then lockout individual sites but I found that was the exception rather than the rule. All in all it worked pretty darn good for me.

 

[marksmith]

It sounds like the scanner will have a longer start up time, but will handle the process better than I expected. Once it's past the rather list of 'lock outs' from startup, the design is so that it minimizes impact to the mobile user. It also appears that I will have to assign gps locations to all of the conventional sites unless I want them 'all' scanned along with the non-locked out sites. GPS locs are already provided for the large, state wide, networks I wanted to monitor. I will now have to arbritarily assign a loc for a county or city system. That will be fun.
Thank you everyone for your information on this. It sounds like I was over-thinking the problem.
I got some nice, but cheap, gps modules a year ago and will now use them.

Thanks again,
Fred

There is a tool in freescan to help with assigning gps coordinates and range. Based on Google maps.

536/436/ws1095/996p2/996xt/325p2/396xt/psr800/396t/HP-1/HP-2 & others

 

[N9JIG]

There is a tool in freescan to help with assigning gps coordinates and range. Based on Google maps.

536/436/ws1095/996p2/996xt/325p2/396xt/psr800/396t/HP-1/HP-2 & others

ARC-XT does that as well.

 

[ofd8001]

I will now have to arbritarily assign a loc for a county or city system. That will be fun.

If you are using FreeScan, I believe it imports location data for conventional systems. It can be found in the group section. About all you have to do is check the box saying you want to use location data. (Also good idea to use the tool to confirm it is the correct location).