Problem programming Kenwood TK-760 “unlock” message when tx on channels above 2

[JCase]

Greetings all,

 I conducted several searches in case this topic was already addressed but found nothing.

 

 I programmed a Kenwood TK-760 and from all appearances the information was successful, except........I am not able to transmit on any channels above channel 2. Each time I key the radio I hear an error tone and the screen displays “unlock” and radio fails to transmit. I have verified that nothing offering password protection has been setup and can receive with no issues, I just can’t transmit. I have reprogrammed the radio several times in case there was an issue writing to the radio but, still get the same results.

In the past, the great members of this site have always been so generous with their knowledge and willingness to help & guide the rest of us when a problem or issue arrises, for which I appreciate and am thankful for. I look forward to any assistance solving this issue.

 

John

WRDM373

[JCase]

My apologies,

 

The radio is a TK-760G(128ch)K according to the programming software.

148-174 frequency range, no option boards.

 I have BCL disabled and all of the frequencies I have programmed into the radio are within the frequency range.

After further testing, I am now only experiencing the “unlock” message/no transmitting on radio channels 3 & 4, all other programmed channels are tx & rx as normal. I’ve checked all the menu options and don’t find anything that would explain or correct this issue. I even programmed the same two frequencies on different channels and they tx & rx as normal. So for now, I just won’t use channels 3 & 4 lol. 

 

Thank you to everyone that replied so far.

John

 

PS- thank you for the link to the manual but, I already have a printed copy and can’t find anything listed that would explain or correct the issue.

[JohnE]

the 760 is VHF not U

[JCase]

Greetings,

I’m well aware that this radio is VHF, you misunderstood what I was trying to say. Channel two (2) refers to the radio channel, not GMRS but thanks for the reply.

JC

 

[Lscott]

You didn’t specify what frequencies you programmed into the radio. There are two frequency spilt versions of this radio. Which one do you have?

[PACNWComms]

You are correct on the unit itself not being locked, as that would display "Password" on the LCD if it was locked. However, it could be receiving on frequency and channel, with Busy Channel Lockout enabled. If you open squelch, can you hear radio traffic?

I'll attach the user manual, maybe you will find something I have missed. That is an older Kenwood, but a great series when they are working correctly. Used often to build repeaters, and for out of band use. (Just stay away from TK-941's if you get into 900 MHz amateur use.)

 

users-manual-125612TK760.pdf

[Lscott]

You might be unlucky to have a memory chip in the radio that has partially failed, a few bad bits in some memory locations. If that's the case don't be surprised if you later notice some other things don't work right. 

[gortex2]

being you dont list frequencies its hard for us to guess. If one channel is 144 nd one is 151 that can explain issues. VCO unlock can happen if the radio was retuned for a specific band. More info can help. 

[gman1971]

5 hours ago, Lscott said:

You might be unlucky to have a memory chip in the radio that has partially failed, a few bad bits in some memory locations. If that's the case don't be surprised if you later notice some other things don't work right. 

Couldn't the OP just reflash the radio with a fresh firmware copy? Saving the tuning partition first before dumping new fw on the radio, if the bits are failing maybe the flash can fix it?

G.

[Lscott]

34 minutes ago, gman1971 said:

Couldn't the OP just reflash the radio with a fresh firmware copy? Saving the tuning partition first before dumping new fw on the radio, if the bits are failing maybe the flash can fix it?

G.

If the chip is failing nothing is going to fix it except a replacement. I'm just suspecting that's the problem, a few failing bits, because he said he can program other channels with the same setup and they work.

[gman1971]

Just now, Lscott said:

If the chip is failing nothing is going to fix it except a replacement. I'm just suspecting that's the problem, a few failing bits, because he said he can program other channels with the same setup and they work.

You are right, bummer... 

G.

[Lscott]

1 minute ago, gman1971 said:

You are right, bummer... 

G.

Oh, one thought did come to mind. If the the radio can be read then compare the code plug that was written to the one read out of the radio. If the chip is buggered up the two should be different. That will likely settle the issue.

[JCase]

Thanks to everyone that replied and offered suggestions.

 

considering this thread closed