pin numbering method question

[rbigg]

Got a radio with a power plug I'm going to have to make up a power cable<br />for.<br /><br />The chassis receptacle is a 4 pin microphone female fitting. It's one of<br />the common mike connectors with a threaded ring.<br /><br />I need to connect +12vdc to pin 1, and pin 4 is ground.<br /><br />My problem is that I'm not sure how the pins are numbered.<br /><br />When I'm looking at the chassis/socket, there's a keyway. The count could<br />be either clockwise or counterclockwise. Which is it? In other words, is<br />pin #1 to the right or left of the keyway?

 

[Paul Moir]

Re: pin numbering method question

Looking at the female socket with the keyway pointed up, #1 should be the first on the right, then clockwise to fourth on the left. I'm pretty sure this is universal, but not certain.<br /><br />

<br />(look real close)<br />Hook it up with a low amp fuse (say, 1A or less) until you're sure about the polarity.

 

[Silvertip]

Re: pin numbering method question

To find the +12 pin, connect an ohm meter + lead to pin 1, - to chassis ground point. Turn radio the switch on. If the meter doesn't show continuity, that pin is not +12v. Move to the next pin. Find the push to talk switch pin the same way.

 

[Boatist]

Re: pin numbering method question

Use an OHM meter to find the ground pin with the power off. Do no use the OHM meter to find 12 volts or your meter will go up in smoke. Set it for VOLTS then try and find the 12 volt pin. <br />I belive Paul is right on the numbering but almost all of those are numbered. The one in the picture Paul sent is numbered. They are hard to read but with a bright light and good eyes you should be able to see the pin numbers.<br /><br /> http://users3.ev1.net/~medcalf/ztx/wire/schem.html

 

[Silvertip]

Re: pin numbering method question

The ohm meter will not be damaged if the unit is not connected to 12V! No harness -- no 12V. Continuity at the device plug with switch on -- yes.

 

[rbigg]

Re: pin numbering method question

Paul is right. The chassis socket pin count goes CCW. <br /><br />Thanks for the help from all.