JT1000 Out of Band Programming

[W4KRR]

I read the instructions found elswhere on this site about hex editing the codeplug to make the JT1000 Front Panel Programmable out of band.

The example used is for a 450-520 split radio to make go down to 440 or so. I have a 403-470 split radio, I want to FPP to about 475 or so, is the procedure listed the same?

I ask because the instructions in part say "Change byte at offset 0x06 from 53 to 52 (S to R)". I found that the unmodified byte of offset 0x06 is already 52, so do I leave it, or change it to 53? I tried it both ways, and it doesn't work, I still cant face program above 470.000 Mhz.

Perhaps the procedure is different to program a radio above the upper limit, as opposed to lower, as in the example on this site?

[RadioSouth]

Besides bit banging I believe there was a field in the RSS to set upper and lower frequency limits.

[W4KRR]

Besides bit banging I believe there was a field in the RSS to set upper and lower frequency limits.

There is; that was another part of the instructions. Yes, I did change it, but it didn't work. Like I said, it tells you to change a particular value in the hex editor, but it's already that value before you change it. That's why I inquired if there was different instructions for going higher in a different bandsplit radio.

[Wile E. Coyote]

Correct, a UHF model it will only allow 403-470. However, if you hold down the SHIFT key in RSS while entering the frequency numbers (not the decimal point), it will allow frequencies from 375-575!

For example, if you want a frequency of 485.25000 in the RX field, you would type:

$*%.@%)))

Good Luck,
WEC

[edit] - Oops, This will not make it front face programmable out of band. I should read these posts a little closer next time.

[W4KRR]

I guess another way to ask this is, the procedure and example listed here:
http://batlabs.com/visar.html

Is written for going down below 450 mhz on a 450-520 split model; is the same exact procedure supposed to work in going above 470Mhz on a 403-470 MHz model? I am trying it, and at the part where you're supposed to change the frequency limits, I get an error message about being out of band, and it reverts to 470.0 before I can exit.

[John]

The procedures you referenced are to change a mid-split (S model 450-520MHz) radio to a low-split (R model 403-470MHz). Just the opposite of what you say you want to do. What you need to do is change the value from 52 (R) to 53 (S) and then follow the rest of the procedures. After changing the archive value as stated above you should then be able to read the codeplug and change the range listed for FPP program per the instructions. Then save the archive and hex-edit it again back to the original 52 (R) model number.

I haven't tried this but it seems straight forward enough....

John

[W4KRR]

II wasn't sure of the meaning of the "S to R" reference, but thanks for clearing that up.

The problem is that when I get to the step that requires you to go to the JT-1000 option screen and change the upper limit to something higher than 470.0. When I change it to, say, 475.0, I get an error message that the value must be between 403.0 and 470.0, and it just reverts back to 470.0 before I exit. I can change it, but it reverts back before I can exit that screen.

[John]

When you open the codeplug file after editing it, what model number does it show? Is it still showing and R model or an S model?

John

[techie]

It is also possible to go in with a hex editor, and simply change the band limits up or down, without changing the model. I did that several years ago with my S model, and by trial end error, I got it down to about 435 on the low side. There are several locations where the value needs to be changed.

[W4KRR]

When you open the codeplug file after editing it, what model number does it show? Is it still showing and R model or an S model?

John

I am able to get it to show that the bandsplit has changed. The 403-470 radio will then show as a 450-520. But when I save the codeplug and try to load it into the radio, I get an "Invalid Model" error message.

I wouldn't think that it should show it this way, because there wouldn't be any point to changing the upper limit to something a little higher than 470.0Mhz, as it already shows 520 as the upper limit.

[John]

The procedures you referenced on Batlabs show you must change the model number back to the original (R in your case) BEFORE attempting to save them to the radio. In short:

- HEXEDIT the model number from R to S in the archive file (use a copy)

- Open in RSS and change the band limits (F4-F3-F2-F3)

- SAVE the archive file

- HEXEDIT the just saved archive file back from S back to R

- THEN open the modified archive file in RSS and write it to the radio

From your posting it doesn't sound like you have completed all those steps.

If TECHIE could remember what locations in the archive were hacked to change the limits directly it would be much appreciated.

John

[John]

OK, I did a little experimenting and comparing. It appears the FPP freq limits are stored in the archive file at offsets 069-06A for the lower limit and 06B-06C for the upperlimits.

So, if you use your hexeditor to change:

06B 12 stays the same
06C 5C change to 8E

125C = 4700
128E = 4750

When I did that it showed up as the changed limits in the RSS screen (F4-F3-F2-F3). However, I don't have a JT1000 to actually try it and see if it will work.. so, it is still somewhat at your own risk.

John

PS

069 0F equals 4030
06A BE

[W4KRR]

Thanks for your replies, John. I finally got it working. I can confirm that manually changing value 06C from 5C to 8E will change the value in the JT1000 Options screen to a high of 475.0. When I skipped this step and tried to manually change it, I kept getting "Value Out of Range, must be between 403.0 and 470.0", and I couldn't get past that point. But then I was sure I had it, but when I tried to load the modified codeplug, I got "Incompatable Model Number" error. I'm not even sure I could replicate what I did to resolve it, but anyway I can now FPP from 403.0 to 475.0MHz. I should have tried for 480.0!

[CGRESQ192]

In response to this old thread.

I am trying to do something similar

I have a 450-512 and would like to do FPP to work on the ham band frequencies (440)

Essentially make it a 440-480 FPP.

I've been able to program it via RSS out of band with the shift trick, however when I try to FPP a 440 freq it says "error"

Any input is appreciated

[Jim2121]

In response to this old thread.

I am trying to do something similar

I have a 450-512 and would like to do FPP to work on the ham band frequencies (440)

Essentially make it a 440-480 FPP.

I've been able to program it via RSS out of band with the shift trick, however when I try to FPP a 440 freq it says "error"

Any input is appreciated

Unless you put the programming Key on it won't work! Unless you have put a diode inside the radio? http://www.batlabs.com/images/jt1000k.gif
Or your HEX is incorrect?

[CGRESQ192]

Sorry

Forgot to mention the Gov codeplug mod was performed.

So it is FPP without the Key, however I can't go out of band.

[John]

The following info is from BatLab. I haven't personally tried this but it seems to do exactly what you are looking for.

Out of Band Programming (JT1000)

To make the JT1000 capable of being field programmed out of band:

(For a UHF radio, but can be easily modified for other bands/splits) This is assuming that you want to make a 450-520 radio into a 440 (or lower) radio.

Make a backup copy of the archive.
Load the archive into your hex editor.
Change byte at offset 0x06 from 53 to 52 (S to R)
Start your properly purchased and licensed copy of software RVN-4098G, version 03.02.01 or higher.

Load the archive (F3-F3 from the main menu)
Go to the JT-1000 option screen (F4-F3-F2-F3 from the main menu)
Adjust the Freq. Range low limit to the low side that you want (the lowest it will go is 403.0000)
Save the archive (F3-F7 from the main menu)
Exit the RSS.
Load the archive into your text editor

Change the byte at offset 0x06 from 52 to 53 (R to S)
Go back into the RSS and program the radio with the modified codeplug.
The radio will now be able to be field programmed with out-of-band frequencies. Note that if you have a frequency out of the original programming band, and you load the archive and go to modify the frequencies in the RSS via F4-F4, it will give you an error. Ignore it. If you say OK, it won’t change anything.

[CGRESQ192]

I've tried this and when I try to change the range in the RSS I get

"Value out of range, must be between 450-512"

It won't let me go any further into saving the archive etc, (rest of the steps)

I've verified the hex entry is correct and the correct RSS is being used.

[CGRESQ192]

Issue resolved.