Batboard

I've heard rumors that the GTX-900 radios can be programmed for up to 15 channels instead of only ten.

Anyone have this info?

K1ATV

I've heard that too. I believe you can hex-edit the RSS to allow more channels, but the display won't show anything recognizable.

Bob M.

I also heard that, but have yet to see one....
even if its done via lab/hex/tool ect.... I'll bet not all of the band will work.
But I just thought of someone I can ask.... so I'll post back if he did it?

W6JK had a four channel radio on eBay with FOURTEEN channels! Go here to see it

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... %3AIT&rd=1

Bil
Mesa

That's a hand-held model with NO keyboard or display, just a rotary switch on the top. So the problem of channel numbers appearing incorrectly does not apply to that radio.

Bob M.

Well, if it can be done - but how - with the four channel radio it must be possible with the TEN channel.

I know the display would be funny on the extra channels.

I ask again, HOW? How would *I* do it?

K1ATV
Mesa

Start at the bottom of this page:

http://www.bluefeathertech.com/kc7gr/gtx.html

It has a link to another thread on this board that may or may not be any easier to understand.

Bob M.

Yes it can be done.

All that is required is a little bit banging.

The extra 4 channels are displayed as unique combination of segements.

I got the information from AR902Mhz@yahoogroups.com

If you can't find it there, I can dig through my notes.

I'm not a member of the 902 group because they wouldn't let me talk about HAM TV on that board.

In fact, the description of the group was changed because of me.

It's my opinion that the narrow FM guys can't operate in a vacuum.

K1ATV HAM TV

What follows is about my experience with the basic portable, but I would expect that similar things could be done with other GTX models.

There are two software mods needed to program the GTX radios this way.
First, there's a mod to get it to accept frequencies in the ham band,
described here:

http://www.bluefeathertech.com/kc7gr/gtx.html

In the last paragraph, "this link":

http://batboard.batlabs.com/viewtopic.php?t=14931

goes to a Batlabs thread about the 14 channel hack. All that's missing is
how to fix the checksum after banging the bits. Iff you're doing the 14
channel hack after having done the ham band hack:

* Go to location 43Dh. Change the byte value from 40 (an '@' symbol) to 23 (a '#' symbol).

All but one of the trunking personalities can be deleted, and the remaining
one can be set to Inactive. Your conventional personalities will be
numbered 2 through 15, which will appear as channels 1 - 14 with the
trunking inactive. You can actually program 16 conventionals (2 - 17), but
don't do it. The radio will become confused whenever you select one of
those last two channels and you'll have to cycle the power off and back on (with a valid channel selected) to get it working again.

Jeff