Batboard

Hello:
I have a GM300 UHF 40 watt 12.5 narrow band factory radio that the logic bd got water damaged.
The 12.5 narrow bad RF bd looks good.
Now I do have several wide band GM300 mobiles that since the jan 1 dead line came for narrow band compliance that have become some what useless.
So id like to blank a 25khz programmed logic bd and reinitiate it as 12.5 narrow band.
Has anyone blanked a GM300 with maxtrac lab then reinitiated it with normal GM300 rss ?
In other words whats the easiest way to blank and reinitiate the bd from 25 wide band to 12.5 narrow band in the GM300 mobile ?
Im not up on hex editing so would rather blank and use my service monitor to setup the blanked bd if i could.
I have done many maxtracs but this is my first on a GM300.
Give me your options .
Thank You Satelite

Satelite wrote:Hello:
I have a GM300 UHF 40 watt 12.5 narrow band factory radio that the logic bd got water damaged.
The 12.5 narrow bad RF bd looks good.
Now I do have several wide band GM300 mobiles that since the jan 1 dead line came for narrow band compliance that have become some what useless.
So id like to blank a 25khz programmed logic bd and reinitiate it as 12.5 narrow band.
Has anyone blanked a GM300 with maxtrac lab then reinitiated it with normal GM300 rss ?
In other words whats the easiest way to blank and reinitiate the bd from 25 wide band to 12.5 narrow band in the GM300 mobile ?
Im not up on hex editing so would rather blank and use my service monitor to setup the blanked bd if i could.
I have done many maxtracs but this is my first on a GM300.
Give me your options .
Thank You Satelite

In what application are these radios going to be used in?

There was a narrow banding kit from Motorola that was available to make the receivers play better in the narrow band mode. This changed the receive IF filter and changed some component values to bring the recovered receive audio back up to an acceptable level.

No one has ever come back and told the world how the transmitters were narrow banded other than just turning the deviation down. Adjusting the deviation down does not qualify the transmitter as being narrow band accepted by the FCC.

Maybe I am missing something here in understanding the use of this radio in narrow band service.

Jim

GM300 blanking method can be found here:

http://batboard.batlabs.com/viewtopic.php?f=1&t=58185

The factory 12.5 radios should be NB accepted. You could look up the FCC ID number on the OET page to be sure.
There were several components in the TX that are different from WB.
You won't get all the "splinters" that come with NB "channel" steps, just what the GM's did in WB.
And I don't see any need to blank and re-init. Just put your NB RF board in and do an the alignment as if you had replaced the logic board.
The only thing that blank and re-init would give you is the serial number on the chassis and the one that comes up in RSS would match. Or if you were going "improve" the model features. Which then would make the model number not match the chassis.

Hello;
Jim202 : The gm300 mentioned has been in the 12.5 narrow band service since the day it was made by Motorola from the factory as a narrow band mobile.
You could order the GM300 25k wide or 12.5 k narrow from the factory just as you could the GP300 / P110 / GP350 ect.
The radios use a tighter rf filter to get the tx to 12.5 .
I have the kits info sheet and there really wasn't a terrible amount of work to change one but with kits at 80 dollars plus sometime back I didn't feel it was worth the effort and purchased the GM300 model number M44GMC09C3A which is the 16ch 40 watt 12.5 from factory.
Yes Motorola did make a narrow band kit to convert the wide band gm300 to narrow band.
But its my understanding that they weren't fcc accepted.
And the kit was for the rf bd not the logic bd.( I have a bad logic bd not rf bd which mine is ok.)
I have a factory 40 watt 12.5 narrow band compliant radio that its logic bd went bad.
I have several wide band programmed logic bds.
Id like to blank the wide band programmed logic and and reinitiate it as a narrow band programmed logic bd,
The narrow band and wide band logic bds are exactly the same per my repair manual and looking at the two radios bds they are also the same bd.
But if I put a wide band logic bd in then the rss will read it as a wide band model number till reinitiated properly as a narrow band.
Im aware it wont do the splits but the GM300 never did from factory.
So id like to know if I can blank it with maxtrac lab and then use gm300 rss to reinitiate as a gm300 16ch 40 watt 12.5 narrow band as it is now but with a good working logic bd being put in place of the bad logic bd and reinitiated tuned setup ect per service monitor ?
Wavetar appreciate the link to the hex editing but im not familiar with hex editing so was looking to go the I qeuss possibly harder way but one im familiar with as ive done with maxtracs ect.
Thank You
Satelite

PETNRDX wrote: And I don't see any need to blank and re-init. Just put your NB RF board in and do an the alignment as if you had replaced the logic board.

As PETNRDX says.....
Just put your 12.5k spacing RF board in and do the full alignment and setting the deviation to +/- 2.5 khz.

Hello Will;
If i do just swap the wide band for the narrow band logic bd wouldn't the rss read the logic bd as a wide band model number since it wasn't intiated as narrow model ?
Reason im concerned is i don't want the radio for example going in for repair at a different shop and they read it with rss and it says its a M44GMC20C3A wide rather than the M44GMC09C3A narrow that it was from factory.
Thank You
Satelite

If you blank it without then putting about 16 hex bytes into the radio with one of the bit-banger programs, the GM300 software will not do anything with the radio. MaxTracs can be wiped clean and initialized, but not GM300s; they need those 16 bytes to be set properly before the software will even recognize it as a "blank" GM300.

Bob M.

Hello:
Oh ok now that pretty much tells me I cant do the maxtrac lab blank and reinitiate with GM300 rss .
Well unless I figure out wavetars hex edit method im pretty much stuck.
Too bad there wasn't an easier way to get a logic bd programmed as 25 wide band originaly to read as a 12.5 narrow band model number.
Am i correct in assuming the radio would read the logic bd as a wide band model number if it came from a parts radio as wide band originaly and placed into a narrow band radio for logic bd replacement as a repair ?
Thank You
Satelite

You'll be fine. You have a NB RF brd. That's all that matters. Drop in a WB logic board to test the radio to see if anything else was affected by water damage, and then proceed from there.

There are two or three bytes in the radio's code plug that are matched with data in the GM300 software's MDF file. This determines the model number and all the other features of the radio, such as the frequency limits, number of channels, output power, coded squelch, scanning, etc. A lot of information is written into the code plug based on the particular entry in the MDF file, but the model number is NOT present in the radio. The serial number is, all the mode data, and of course the tuning data.

To blank a GM300 to the point where the programming software will be able to continue the job, you still need to set some bytes in the code plug that tell the software what model series the radio is (M10, M100, M200, GM300, and its variations). A program specifically written to blank the radio would need to at least know that much, and it would have to set the serial number to spaces and possibly calculate and set one checksum byte. You end up doing all that by bit-banging the data into the erased/blank code plug with MaxTrac lab. There's just no other method for you to use. Either you learn how to do the bit-banging, or send the radio to someone who already knows how to do it, or just mark the radio somehow without changing the model number so the next person knows it's got a narrow-band RF board in it.

Bob M.

Hello:
Thank you for all the info.
I now have an understanding of what im up against per my direction of thought.
I don't see any other way to get it done now either other than learn hex editing which for now im not going to pursue .
It will most likely become a parts radio if I need an rf bd ect.
Thank You for the great info.
Satelite

Huh? Put a logic board in, and give it a whirl to see if anything else died before declaring the thing a parts radio.

Hello:
No im not comfortable with the radio reading as a wide band even though it has a narrow band rf bd.
If that radio goes to another radio shop and they read it as a Wide Band ill never hear the end of it.
So its not going to be done.
I already know the narrow band UHF rf bd (438 to 470 MHz ) is good from swapping it into another known good radio and retuned ect per service monitor.
I kept the rf bd from the other radio rather than going through the hassle of swapping back since it worked just fine.
No damage was seen on the rf bd and was on the logic bd only so im not concerned about the rf bd swap.
I was hoping to blank and reinitiate a wide programmed logic bd into a narrow so when read by rss it said it was a narrow band so no other shop could say otherwise.
But that's not going to happen because im not going to pursue it.
Now if I get a couple or more with bad logic bds then maybe ill look into it but not for just one radio.
I have a narrow band VHF rf bd and a vhf narrow logic bd that ill most likely put into the chassis and plastic from the uhf radio with out a rf bd to complete a radio anyway and put the narrow uhf rf bd on the parts shelf.
Thank You
Satelite

Okey dokey

GM300's CAN be blanked & re-initialized. The link I posted isn't for 'hex editing'...it's using the Maxtrac LAB RSS to 'blank' the board, and then using the bit banger functionality to make some changes to have the GM300 RSS recognize it as a blank board & allow proper re-initialization. It really doesn't get any easier.