Hacking the Kenwood Tk-3130 for custom GMRS channels and Tones

[Timberwulf]

I wanted to keep the 15 channel functionality, but when using the KPG-75D V1.10 software, the channels are grayed out giving you a preset GMRS/FRS combo or a combo with FRS/GMRS repeaters. It also doesnt give you options for PL (QT) Tones.

So I saved the default 15ch .DAT file, downloaded a hex editor, and reverse engineered how its programmed.

In the attached picture you will see the modified channel list in the KPG-75D software.

I wanted the 8 GMRS only channels CSQ for simplex, with an addition 7 setup for repeater use with PL (QT) tone 141.3. I found if you set the pl tone on the handset, it sets for all channels which didnt work for me.

The picture on the right is the hex editor. On the 4th line down (starting 00000030), I noticed the numbers are in reverse order. 00 50 25 46 is really 46 25 50 00, or 462.55000. The first set (in red box, columns 00-03) is the RX side. Columns 04-07 (green box) are the TX side.

If you look at the purple box (row 000000b0) (9 rows down being channel 9) on columns (08-09) that is the RX PL (QT) Tone 13 14. In reverse its 14 13 or 141.3. Columns (0a-0b) in the orange box is the TX PL (QT) tone, also 13 14 or 141.3.

I'm still decoding the rest of of the options in the hex editor but this should give you the basic idea. Dont know if this is common knowledge, I did a lot of googling and found nothing so decided to venture out on my own, hope this helps someone else.

Just uploaded the files between two TK3130s did some testing and everything seems to be working. I was able to hit an open local repeater as well on channel 9.

If anyone has decoded the other options please let me know, I'm dying to unlock the whole system.

 

[mmckenna]

Interesting, and good job!

I did that long ago on a Motorola radio to change it from a 2 channel to a 16 channel.

 

[Timberwulf]

Thank you.

I also found you can edit the LNG (language) and CNT files in the kenwood program. I opened them in wordpad and noticed some of the script registers have been commented out, (// turns them off). That will be my next adventure once I figure out all the hex blocks.

This is all new to me but I have a diverse IT background so this has been a fun experiment. I think im going to love Radio.

 

[mmckenna]

Yeah it's kind of fun. I know a guy that did a lot of this at one time. Was good at getting some not so old Motorola gear to do things it wasn't necessarily intended to do.

If you ever decide to try this on any Motorola gear, take a look over at Batwing Laboratories There are some really good tutorials on how to do this exact type of modification to that equipment.

 

[Timberwulf]

I will definately do so. I have two motorola m1225 Im having programmed (came with purchase), but i already ordered a cable and found the software and will likely dig in when they arrive.