Fox Tango International

[KB3JZD]

I was wondering what would cause the up/down scanning buttons to quit working on an MD-1 microphone ? I am using this with an FT-757gx. They worked fine then quit one day .

[Ghostwriter]

Hello Ron,

I'd say the most logical source for the Yaesu MD-1 Desk Microphone for Failure is the Coil Cord between the FT-757GX Transceiver and the MD-1 Desk Microphone. If you purchased the transceiver new, then you should have a copy of the Yaesu Owner's Manual and on Page # 17 they provide a Schematic Wiring Diagram of the MD-1 & Coil Cord Assembly.

This is the first place to start your troubleshooting procedure with MD-1 Up/Down wiring by taking an Ohm Meter and checking the continuity between both ends of the Coil Cord. Perhaps with everyday use one or more wires have broken in the Coil Cord Cable or at either End on the Microphone Connectors.

If the Coil Cord test out Good, then insert one end Plug back into the FT-757GX transceiver taking a short piece of (solid) wire or a paper clip and insert into the other Plug / Connector End on Pins # 1 & 2 Simulating the Up Button Or Pins # 2 & 3 Simulating the Down Button. If the Up/Down functions work fine, then the problem points at the MD-1 Desk Microphone Base Unit which will need to be disassembled for further troubleshooting and replacement of parts. If the Up/Down functions still do not work correctly and you've Checked the Coil Cord for continuity, then the problem points to the FT-757GX transceiver as being at Fault, which will need to be openned up and troubleshot at module level.

Now, IF you do not have the YAESU Manuals & Schematics I am providing the Fox Tango Club's Web Page so you can Download all of the information for Troubleshooting and the Parts List:

http://www.securesystemsnw.com/ft/ft-library/Eighties/Eighties.htm

Good Luck finding the source of the problem.

73,

Dan
WA9WVX

[KB3JZD]

Thanks ! I'll do some checking. This happened after I changed the battery in the radio .

[KB3JZD]

Well I guess I win the dunce award. I took apart the mic connector on the radio end and saw only 3 wires. This caused a big "warning" of "stupid" going off in my mind. Here I had attached the wrong cord to the mic . The coiled cord which has all the needed wires connected for scan goes from the mic base to the radio. All this time I was sad my scanning buttons didn't work. Oh well I'll know the next time !

[Ghostwriter]

Hi Ron,

OMG!!! It's happened to the best of us!!!

73,

Dan
WA9WVX