GM 300 scan feature

[robbip]

G'Day All,
I have a GM 300 VHF which I use for 2m Ham work inside the house.
It came with a desk mike and therefore won't scan.
Is there a way to make the radio scan while using this mike (HMN1038B).
Any help will be much apreciated.
Peter R
VK5FRAQ

[jackhackett]

I don't see why it wouldn't scan using that mic, unless the monitor switch circuit has been broken or modified.

You can find a schematic of the mic here:

http://www.repeater-builder.com/maxtrac ... 900mhz.pdf

[robbip]

It scans ok but the mike should be on the hook to get it to scan
There must be a go round for it

[kcbooboo]

MaxTrac software has an option in the radio-wide screen about "Hang-Up Box: Yes/No". If you select NO, the radio won't care about the signal that would come from a mobile mike or a desk mike with a Monitor button.

Alternatively, pull the control head off the radio, remove the volume control knob, remove the circuit board behind it, and add a jumper from pin 3 to pin 4 of the RJ45 jack. Pin 1 is closest to the volume control and probably has a square pad on the circuit board identifying it as such. The jumper will permanently ground the Monitor line so the radio will act as if you've selected NO in the software.

Bob M.

[robbip]

Thanks Bob
That should give me What I want

[jackhackett]

I must be missing something... the desk mic should always be "on hook" unless you press the monitor key down.

[Bill_G]

Someone may have installed the csq jumper in the mic. Hard to say without it being in front of us.