hi about a month ago i purchased a radio shack ...realistic desk microphone off eBay .......its a 4 pin connector on it the item # for it is 21-1170.....i was wanting to get the owners manual or instruction sheet for this mic ....ive looked all over the internet to no avail........i did find the part number by looking up old radio shack catalogs .......the last catalog this mic was in was 1976........it looks like the old turner plus 2 mike but im not sure if its the same wiring ....i hooked it up to my cobra 19dx and it didn't work ....i didn't key it up ....but when hooked up no sound came out of the speaker on the radio.......im hoping someone will have this manual or schematic diagram so i can wire this up to any radio i chose ........also i will help me to know which way to put the switch on the bottom for relay or electronic switching ........thanks in advance for all reply's ..........Eric.......