Motorola Type II SmartZone Rebanding Question

[trunktracking]

Here in Orange County, Florida I monitor the MOTOROLA 1F36 Type II, 28 Channel SmartZone Trunking System. The system was placed into service in 1993 and is getting ready to obtain a $20.7M upgrade to P25.

Since the County started their rebanding project a few months ago, some of my radio scanners (which are rebanded, programmed correctly and contain the latest firmware version) are missing some transmissions.

When I use my Uniden HomePatrol, every conversation is heard, though when I use either my Uniden BC396/996/XT Series, I miss certain transmissions.

Backgound:

The County has already touched their radio's once with the new rebanded frequencies and is getting ready to touch them a second time to remove the old information (this per the Trunked System Manager).

Question:

If a trunked scanner is rebanded and programmed directly, what could cause a scanner to miss transmissions? (Given A Trunked System's Architecture)

In other words, what could cause my HomePatrol to hear everything and a 1 year old rebanded scanner to miss certain transmissions?

I present this question here as I know for a fact my scanner is programmed properly...

Best Regards,

Joe, WX4ADX
DSRS Net Founder
D-STAR Radio Scanning Net
Radio Reference Feed Provider:
Orange County, Florida Sheriff's Office, Admin. 1

 

[mtindor]

Here in Orange County, Florida I monitor the MOTOROLA 1F36 Type II, 28 Channel SmartZone Trunking System. The system was placed into service in 1993 and is getting ready to obtain a $20.7M upgrade to P25.

Since the County started their rebanding project, some of my radio scanners (which are rebanded, programmed correctly and contain the latest firmware version) are missing some transmissions.

When I use my Uniden HomePatrol, every conversation is heard, though when I use either my Uniden BC396/996/XT Series, I miss certain transmissions.

Backgound:

The County has already touched their radio's once with the new rebanded frequencies and is getting ready to touch them a second time to remove the old information (this per the Trunked System Manager).

Question:

If a trunked scanner is rebanded and programmed directly, what could cause a scanner to miss transmissions? (Given A Trunked System's Architecture)

In other words, what could cause my HomePatrol to hear everything and a 1 year old rebanded scanner to miss certain transmissions?

I present this question here as I know for a fact my scanner is programmed properly...

Best Regards,

Joe, WX4ADX
DSRS Net Founder
D-STAR Radio Scanning Net
Radio Reference Feed Provider:
Orange County, Florida Sheriff's Office, Admin. 1

I'm not sure how it is done with the Unidens, but if your scanner is a GRE/RS model then you not only have to have the rebanded frequencies (at least all possible control channels) AND you must set up a custom trunking table.

I use GRE/RS products and use Win500 to program them. I import the trunked system into Win500. I then select a custom bandplan and I specify 800 Mhz Rebanded. When I upload it to my scanner it puts a specific trunking table in the scanner.

So, if you manually program a rebanded trunked system into your scanner, or if you are using a program to import RR data and a custom trunking table isn't set, then won't necessarily be able to track all of system.

In my county, even though they have already rebanded, any scanner capable of Moto trunktracking will track the system because the frequencies in use on my county's trunked system are not ones that rely upon a different bandplan. For the county just south of me, in order for that Moto system to be tracked properly the scanner has to have the custom bandplan in it since some of the frequencies in use on that particular system are not part of the default bandplan.

My guess is you don't have a custom trunking table set on your scanners that you programmed but that the RR data is correct and the HP-1 properly uses the flag in the RRDB that indicates it is a rebanded system and uses the appropriate custom bandplan.

For more info regarding what I"m talking about, check out:

Main Page - UtahRadio
- read the Custom Band Plans and rebanded sections

I'm sure that information is in the RR Wiki somewhere, but I've always liked the way UtahRadio has it presented so that is the link I provide.

Mike

 

[n5ims]

You may need to create a custom bandplan for the rebanded system(s) to allow your scanner to track them. See the "Edit Band Plan" section here for details on how --> Easier to Read BCD996XT Digital Scanner Manual site

What's going on is the system is sending a "channel number" out that your scanner isn't translating correctly. This custom band plan will allow it to translate it properly.

 

[trunktracking]

Custom Band Plan Follow-Up

All,

I have tried all of the Custom Band Plans offered (after reading your links and suggestions) and none of them seem to work. Actually, any of the custom band plans make the system sound garbly.

The County has decided to transition their Sheriff's Office to full-time encryption, on every talk group, in 12 months when they go to P25 (according to the County Radio Programming Manager) and likewise he as the programming manager will not share any scanner reprogramming information.

I am starting to wonder if this not an attempt to keep people from listening 'accurately' to the Orange County, Florida 1F36 trunked radio system.

Best Regards,

Joe, WX4ADX

 

[ka3jjz]

The signal being 'garbly' has likely nothing to do with rebanding. It's more likely that a little P25 adjustment is required, or there's been a loss of signal strength - possibly due to the power at the transmitters being turned down. There's been some reports in other systems that have done rebanding that this has occurred - maybe to tweak the system or test it before returning it to full power at some future point.

If you can trunk a particular talkgroup and not lose the conversation, you've likely got the custom tables correct, 'garbly' or not. best regards...Mike

 

[RKG]

I tend to agree with the above diagnoses.

Rebanding uses a new table to convert an integer value into a frequency in MHz for changing to a voice channel on a channel grant OSW.

The new table continues the same codes for the same frequencies that were available under the "old" channel plan, but it uses new values for channels that were not previously available.

If you are hearing some and missing some, it makes sense that the ones you are hearing are on voice channels with unchanged frequencies (and, hence, unchanged channel numbers) and the ones you are missing are on voice channels using new frequencies (and, hence, new channel numbers that, if you don't have a "rebanding" channel table in your radio, your radio cannot properly decode and follow).