Batboard

It has been a while since I have done any hex editing. I want to change the lower end freq and leave the higher alone, I have found my radio range in the mdf file and have edited there no problem. Now I have been trying all week to get the checksum back with no luck. Would someone please help me out to get this checksum back.

Thanks

I found the front end selectivity
to be poor when I went out of band.
I had a vhf .I had 140 mhz and 173 mhz in the radio and
it did not perform as good as other radios.

What you need to do is take a checksum of the original file before it was hacked and right it down. Take a checksum of the new version as well. Do the math and figure out the differance between the two. Edit bits that are useless (such as the Motorola copyright text) in the file either up or down and keep on checksuming till you get where you need to be.

I just completted a "out of band" mod on a friends SM120 VHF (150-170) and lowered it into the 140 range and he reports that it works just fine.

It was a PAIN trying to get the checksum to match back up again (it took about an hour worth of tinkering).

Give it another try, JUST REMEMBER to make a back-up of your MDF file BEFORE you do the mod, generate a Checksum (again BEFORE the mod), and after the mod generate another checksum... Then sit down and edit a usless area (copyright statement works) and save, genereate checksum, re-edit, generate, re-edit.....

If you haven't gone blind yet, (or insane) you should be able to get the checksum you require. You will come close several times, WRITE DOWN what you did and where, so you can go back.

GOOD LUCK!!

When u did the upgrade did u put it
on the service monitor to see the change.This is a must
when u are doing a good job.

I found the easiest way to edit the MDF is merely swap the information of each bandsplit with each other. Swap the one you have with the one you want. No checksum required, because your not changing it.
Jim

Tried just swapping badsplits in mdf file and no go..........

Radioman2002, please check your personal messages!

Erik

Post from: Susan157

> "When u did the upgrade did u put it on the service monitor to > see the change.This is a must when u are doing a good job."

When I did the mod on a friends SM120 with ver.1 of the RSS, I only "lowered" the band split from 150-170 to 140-170. for the most part going down (or up) a total of 10Mhz should not cause any great problems. Any more of an increase you require running the radio through a few "tests" and have the RF range adjusted.

I also recomended to my friend to try to stay as close to the original 150Mhz range as possible. For the most part, he only needed to get into the 144.000Mhz range. And to date, all has worked fine and he is VERY happy.

It's a pain trying to come up with the correct checksum, but untill someone develops a version of "toolokit" for most (if not all) Motorola radios, well have to do it the old fashion way...