MT1000 VHF VFO Unlocks

[ve1gln]

Hi All,

I just bought a used MT1000 at a fleamarket, when I TX with it, The light flashes 2-3 times, then the VFO unlocks.

I have several batteries, and have tried all of them, it's not a battery problem. I can receive fine on it, and it does actually transmit for the 2 seconds untill it locks up, once it does this, it will neither TX or RX untill the power is toggled.

I have tried programming it with various frequencies, and changing the bandsplit, no go...

Anyone know if this is fixable, or do I now have a MT1000 Scanner

Only paid $5 for the radio, but would still like to get it to work.

Thanks

Glen
VE1GLN

[kb0nly]

Did you verify the bandsplit on the VCO inside?

Sounds like symptoms of pushing it out of it's split, though you did try reprogramming it. You could try grounding the lock detect line and see if then functions correctly, if it does then it's still a programming or hardware issue causing the VCO to unlock.

[ve1gln]

Thats good information, where abouts would I find the Lock Detect line?

I don't have any internals information on the beast.

Thanks

Glen
VE1GLN

[kb0nly]

Remove the guts from the radio and then remove the front shield, at the bottom front of the internals is the VCO module with two small plugs going to it from the controller, the right hand end of the left hand connector is the lock detect line. You can short that last contact to ground to defeat the lock detect line. What i normally do when troubleshooting a radio is take a piece of component lead, clip off a resistor lead for example, and tack solder that to the last contact and let it sit against the controller to keep the lock detect line grounded. You can then use it like a switch, pull it up from the controller and test, push it back down to ground, etc.

Just put the radios guts back into the case without the front shield so you can hook it all up and work on it. Also, while you have it apart, check the bandsplit, it's printed on the top of the VCO under those two plugs.

[ve1gln]

Hmmm, that didn't work...

I grounded it , but it still looses lock.

When I change the band split to 157-174 it works fine.

But The VCO indeed says 146-174 which is what I want.

Any other tricks?

Glen
VE1GLN

[kb0nly]

The only other thing to try is this..

Ground the lock line.
Read the radio.
Change the bandsplit.
Edit at least the first channel to a frequency in that split.
Program the radio.
Turn it off and remove the ground to the lock line.
Turn it back on and see if it work.

If it still doesn't work then you have a bad controller or VCO, leaning towards a bad VCO.

[ve1gln]

Nope didn't work either, and now no matter what split I try, it unlock on ANY frequency... so I guess I now have a 16 Channel VHF receiver.

Oh well, Maybe I will use it to listen to the Harbour Traffic on Marine Frequencies.

Thanks for all your help.

Glen
VE1GLN

[kb0nly]

If you have another controller you could try swapping it, but i think the problem lies with the VCO.

Unfortunately at that point i would be looking to swap the entire RF board rather than dig around and try to fix it anymore.

[ve1gln]

Already tried another controller, didn't matter, so Yeah, I guess the VCO is a gonner.

Thanks for your help, I really appreciate it.

Glen
VE1GLN