QTH.COM Swap Chat

I am looking for the wiring diagram for a EFJOHNSON desk mike. When I pick it up it did not have any wiring or connector.

I want to use it with 7 pin yaesu and do not know where to connect to the board in the mike base

The mike is in new condition from a SK and did not get the paper work

73's

Tom
________
RAMCHARGER

Hello Tom,

Perhaps you can share the Desk Microphone Model Number with us as it could have been manufactured by Shure, Turner or Astastic. Generally all microphones have 4-wires:

Red is P-T-T High

Black is P-T-T Low (Ground)

White or Black is the Microphone High (Hot)

Shield or Silver Braid is the Microphone Low (Ground)

Dan
WA9WVX

It only has a number inside on the board E1A--151--1. Nothing was ever soldered to the board so I do not know where to put what. This is a new mike so to speak.

73's Tom N8UAZ
________
BABI MAC PROVED THAT

Hello Tom,

Okay, I didn't realize that you only had the Desk Microphone less the coilcord or 4 conductoer cable.

Is this Desk Microphone mechanically designed with a square type microphone screen element that you would speak into, with a slanted shaft perhaps at 15 degrees into the rear of a rectangular Brown base and a large square PTT assembly lever or a split PTT / Monitor assembly levers Beige in color and plastic molded?

I'm trying to picture your Desk Microphone to better visualize when it may have been manufactured as to time frame. Microphone designs have changed throughout the years and have been used on Commercial Land Mobile Radio Products rather than Amateur Radio.

This brings up an interesting issue and this is what the Microphone Impedance might be. In the early days most microphone impedances were rated at 50K ohms (Hi-Z) but the Land Mobile Radio microphones almost always were designed to be 500~600 ohms (Lo-Z). This could pose a problem when connecting an audio mismatch impedance to your Amateur Radio equipment causing Low Microphone Audio.

If there were a way for you to post 2 or 3 JPG Photos of the top front, side view and internal base view with the Printed Circuit Board of your Desk Microphone on this forum, it could be easier to identify and perhaps recommend a wiring configuration.

Dan
WA9WVX

I am good on QRZ for an e-mail. If you would e-mail I would send the JPGs of the mike and the board.

Never thought about the impedence. Was more wrried about the wiring

73's

Tom
________
Pot News