Batboard

I have a police vehicle that intermittently is having "key-loading" appear on the display. While "key-loading" is present the radio will not receive or transmit. Due to the intermittent nature I have been unable to witness this myself, so I only have the police officers description of the fault to go off of. Does anyone have an idea of why a radio would randomly go into "key-loading" without being prompted? The radio does have an encryption algorithm present but only when manually activated.

Thanks,

~Andy~

I think the only physical way this can happen is if the Keyload pin in the GCAI connector is being shorted to GND somehow, as if a keyload cable had been attached?

The only other thing I can think of is maybe it's something to do with OTAR, but even that shouldn't make "key-loading" appear on the display?

Andrew

I tried making a secure transmission but an error message appeared "clear talk only". I tried reloading the encryption key and now the radio appears to work fine. I think the encryption key got corrupted somehow.

~Andy~

That sounds more like a symptom than a cause, I wouldn't be surprised if the problem persists.

I believe that under certain circumstances (with FIPS for example), keys will be erased if a keyload cable is attached to the radio and maybe the original key was erased because of the fault?

At the very least I would pull the CH/TIB and make sure the UCM is still seated properly (remember to take ESD precautions), or if you have access to a fleet, try swapping the UCM and carrier out with another radio and see if the problem follows?

Andrew

Andy,

Was there any follow-up on this issue? Did reloading the key fix the problem?

Andrew

It appears that reloading the encryption key has fixed the issue. I have not heard of the problem re-occurring but I cannot say for certain as we are not the only radio shop that services this police agency.
~Andy~

No problem, I was just curious...

I like to at least try to leave a forum thread "solved" for the benefit of anyone with the same problem in the future.

Andrew

Make SURE that the housing for the UCM is properly insulated in the correct spots, including the chassis with Kapton tape. Early housings were not. This could be an issue with some boards if clearance and lead tolerance is tight.