BC785D questions

[JoeyC]

Scanner memory limitations

Lou, is there any reason why they couldn't design the units with more RAM to the scanner and allow larger talkgroup lists thereby creating more alphataggable real estate? With the cost of RAM so cheap these days, I wish this was the answer and if so, why not?

 

[loumaag]

Re: Scanner memory limitations

Lou, is there any reason why they couldn't design the units with more RAM to the scanner and allow larger talkgroup lists thereby creating more alphataggable real estate? With the cost of RAM so cheap these days, I wish this was the answer and if so, why not?

Well no, not really. Of course there is a point of diminishing returns. Say for example currently the max seems to be 100 to 150. Lets Triple that. Say you can enter 300 to 450 TG and associated alpha tags. Seems like a dream huh? Whoa, what happens on every channel grant issued by the CC. Why now instead of checking 100 to 150 slots to see if you have it programmed (either to let the audio pass or to show the Alpha Tag) now the radio has to look at between 300 to 450. Well how long does it take to check 300 to 450? The answer is 3 times as long as it took to check 100 to 150.

So the answer really isn't RAM real estate, it is performance. Why don't they get faster? Well they have. My Pro-90 could store 5 groups of 10 for a total of 50 TG's. Of course it could only scan one trunking bank at a time, with no conventional and no alpha tags. My BC796d can now scan conventional and up to 10 trunking banks with 100 TG's each, and the Pro-96 can do the same but with 150 TG's each. Seem pretty much improved over the first TT scanner.

I don't know how Uniden or GRE has written the software, but I suspect that GRE's is more efficent and that Uniden has just about reched the end of thier rope. I base this on the fact that my Pro-96 can store and check a stack of 150 TG's without errors and still report new ones in Open Mode, whereas my 796d can check 100 TG's and occasionally reports the wrong TG # (I mean like 240 being reported as a new TG 224 which is not even a TG on this system in ID Search). This is observed (and logged) behavior comparing the 796d with Trunker and the Pro-96 all running simultaneously on the same Trunking site. Of course the Uniden allows me to see iCalls or Private Calls (depending on the TRS) and also allows me to see status bits, which the Pro-96 will not. This may account for the lower number of TG slots on the Uniden.

 

[lgentle]

I've been reading a lot of posts in the Trunking Forum so I can better understand how & WHY it works the way it does. Although, I did ask a similar question as JoeyC did about the RAM issue. I asked why don't they just make scanlists a "database"; meaning one memory area where you input all the talkgroups that are listed in the RR Database for your area along with alpha tags. I closed that post by asking if it was because of performance issues. It was finally answered in the last post.

 

[ka3jjz]

I've been reading a lot of posts in the Trunking Forum so I can better understand how & WHY it works the way it does. Although, I did ask a similar question as JoeyC did about the RAM issue. I asked why don't they just make scanlists a "database"; meaning one memory area where you input all the talkgroups that are listed in the RR Database for your area along with alpha tags. I closed that post by asking if it was because of performance issues. It was finally answered in the last post.

Since you seem to need alpha tags so badly on everything you have programmed, and you can't do it with the radio's firmware, you don't have much choice; you must do it with software. There are 2 possibilities;

1. The much respected IDTracker freeware could be used to accomplish this. Typing in all those IDs would be a bear, but in comparison to some other packages, a trivial matter, since if memory serves it uses plain jane CSV files for the lookups.

http://bellsouthpwp.net/k/d/kd5eis/IDTracker/IDTracker.htm

and IDTracker does have some support for the 2052, as well as full support for the Uniden digitals.

2. The other possibility is Radio Manager 2004/Trunk Manager; to me, the editor for building the lookup files is horrible, but it works (no support for the 2052, however)

http://www.bensware.com/rm2002.htm

There is another possibility, though it's much more expensive than the other 2 solutions I mentioned above. Scancat Gold *might* be able to also do this; I fooled around with an earlier version than the current one, and I *think* - I'm not entirely sure - that it too used CSV files to do lookups for any frequency and/or talkgroup. I never particularly liked it; I didn't like the interface layout very much, and there was no support for Multi Tracking (the ability of a scanner to scan both conventional and trunking in a single session, something many of the Unidens can do) so I unloaded it and moved on.

http://www.scancat.com

73s Mike

 

[loumaag]

...I asked why don't they just make scanlists a "database"; meaning one memory area where you input all the talkgroups that are listed in the RR Database for your area along with alpha tags....

I fear you still think that TG's are unique across the board. They are only unique to each system.

If I remember correctly from a way earlier post you live in Baltimore County, MD. Lets take two systems from you area. Talk Group 48 is either the Fire-Central Response channel on the County Pub Safety system or the Telecommunications department on the BG&E system. So, if you only had 1 big list, which one do you put in? Remember if you only have one list, the radio will show that one Alpha Tag so ...

The reason that the lists are the size they are is performance, the reason there are scan lists for each trunking bank is so that each individual TG can be properly identified. Hence, as everyone here has been saying, you can't just have one big database of TG's.

BTW, IDTracker is a fantastic little utility and I love it, but each bank in the IDTracker database still has individual scan lists. :wink:

 

[lgentle]

FINALLY, YAY!!!! My question of why you can't have one big scanlist is answered. I have looked at all of the systems in my area, but I didn't realize or notice that some id's are repeated. I thought id's were unique for each agency (PD, FD, utilities, etc.). Thank You!! Thank You!!

:idea: The lightbulb has finally come on!


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Double-left click or right?
(I still get that A LOT in my profession)

 

[JoeyC]

Certainly you didn't think that every talkgroup was unique to the particular system do you? If that were the case, there would be few talkgroups to be had by the thousands of trunking systems worldwide.

Thanks Lou for the explanation above.

 

[loumaag]

FINALLY, YAY!!!!
.....
:idea: The lightbulb has finally come on!

:lol:
Well I am glad you finally got to see the light. Pretty soon the train was going to run you over.
:lol:

I guess I had been trying to explain that to you from the beginning, but it took a third way of telling you before you got it. The important thing is that you have got it now! :wink:

 

[lgentle]

JoeyC - Yeah, that's what I thought. I figured that every location had their own talkgroup id's. Now, I see that they can be "re-used" by different agencies.

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Double-left click or right?

 

[fmon]

Now, I see that they can be "re-used" by different agencies.

They can be and are often used by other systems in an area, but it is highly unlikely that two or more agencies within one system will be assigned the same ID.

I'm still waiting for some help from Joey C on this question ask earlier. But I know he will come through.

Contrary to what the lgentle said, the 785 does NOT show the alphatag when searching, even if it is programmed as a talkgroup in a scanlist. The 796 does though.

Joey,
Was this an upgrade or did the 296/796 have this from the get go?

Thanks

 

[BANDIT]

I think this was part of the TrunkTracker IV. The 785's are TrunkTracker III. It was not in a software upgrade.

 

[JoeyC]

Sorry, the 796/296 had the ability from the get-go. Probably because they realized the flaw after the 785/250 came out because the 780 had the ability also.

 

[JoeyC]

I think this was part of the TrunkTracker IV. The 785's are TrunkTracker III. It was not in a software upgrade.

The 780 is a Trunktracker III and can display alphatags in search. I believe it was overlooked during the original design of the 785.

 

[lgentle]

OK, my trunking terminology isn't up to snuff yet either. So, other systems in the area can possibly re-use id's but agencies within those systems usually do not?


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Double-left click or right?

 

[fmon]

Thanks Joey and Bandit, I kind of thought so. They sure screwed up on the 250/785. Ah well it's still a pretty good scanner.

 

[JoeyC]

Re-use is not an appropriate word here. There is nothing used and nothing in common amongst separate trunking systems.

A 3600 baud system has 4096 potential talkgroups, and a 9600 baud system, 65536 (I believe).

Look at each system as a book. Each book (system) can put their talkgroups on any of the pages (talkgroups) within the book. If 2 systems want to assign 10 talkgroups and they each want to use the first 10 available, there is nothing re-used, because each system is a unique entity. The books may sit next to each other on the shelf, but they have nothing more in common with the next book except for the fact that they each have pages numbered the same way inside.

What a stupid analogy, but thats all I could think of. :roll:

 

[lgentle]

Makes sense.