Turner M+2 minus the U mods?

[slidetbone]

I got my hand on a vintage Turner M+2. This is not the M+2/U. Internally it is very different than the M+2/U. Older components and no circuit traces. I got it with a 1/4 plug soldered at the end. Now, I have to assume this was designed for use for CB radio. After visually comparing the M+2 with the schematic of the M+2/U, I am no where close to being able to wire this for use on a CB radio. I cannot locate the schematic for the switch. All I can find is part of it from this document which shows the amplifier, but then skips to the +2 base schematic:

http://www.cbtricks.com/mic_manuals/turner/turner_m_plus2.pdf

Anyone ever seen this mic version and know what change in the switch wiring is needed to be done to make it work on Cobra configuration? This switch does not have the mini extra board the M+2/U has for transmit and receive.

 

[Dmans]

slidetbone,
With the type of connector on the cord in your picture, the typical connections are:
-Tip=Push to talk relay control
-Ring=Microphone Audio lead
-Sleeve=Common Chassis ground

I would check the connector that is installed with a DVM and make sure that is how it is wired-Opening the back of the microphone if needed to confirm wire colors.

That should give you 3 of the 4 wires needed. There may well be a 4th wire in the cord (not attached to the current connector) or found in the back of microphone that will probably be needed for your Cobra (assuming the mike needs to be plugged in for receive to operate or known as transistor controlled TX/RX switching).

If there is no 4th wire, wiring this mike to a transistor controlled TX/RX switching type radio may be more trouble than it is worth.

73's
David

 

[slidetbone]

I am afraid you are right. This may be a relay switching mike that is not adaptable to electronic switching as it is now. I spent hours chasing wires and comparing with the M+2/U schematics. I figured there may be something I missed or a mod or sorts to make it work. The mic is almost like new too.

 

[midnight special]

but hey it will work with the galaxy and rci that only need 3 wires to hook up,,,,,

 

[midnight special]

on a other note,, which wiring book are you trying to use? for that mike use the book with turner conrac on the cover and not the turner telex,,, it can be found on here,,,, http://www.cbtricks.com/members/toban/turner/turner1.htm

 

[slidetbone]

I checked it out and that too has the M+2/U version, not the M+2. The one I have does not have the 3 extra contacts for the red and black wire. It appears to be a older pre/U mic. Thanks for looking!

 

[slidetbone]

Forgot to tell you yes, this does have a 4 wire cord. I will spend the time tracing it. The switch is wired very differently than the M+2/U - JM+2/U versions.

 

[Dmans]

slidetbone,
If it has a 4 wire cord (and all wires are hooked up inside the microphone) it should be able to be used with "electronic" or "transistorized" switching.

73's
David