MIKE WIRING GUIDE your best place to learn about wiring microphones, all that's required for any radio/microphone combo is a simple analogue preferrably (as it shows the slightest needle movement,something that helps identify audio wires in power mikes) or digital multimeter, but no biggie as audio should always be inside braided screen.
Robb throwing diagrams at him won't help him, as you have no idea which microphone he is using or whether the microphone or radio has had its wiring changed for numerous reasons.
Firstly the good news, tx'ing and hearing normal rx audio is a good thing ,most likely means wrong microphone or miswired microphone although I would be wary of the words normal rx,it may still need tuning to optomise performance,not a job for an amateur.
What microphone is it?
Is your stalker 20, 4 pin or 5 pin din microphone socket,if I recall most were 4 pin here in europe I may be wrong and an early states version may well have a 5 pin din as Robb states as many early uniden built president/realistics did too.
Sounds to me like you've got the shield/braided wire on the right pin, although that might not be the case,one sure way of finding out is unplugging the radio altogether, setting your multmeter to continuity/buzzer test if it has one or ohms X 100 or x 1000,you then connect one wire of the multimeter to the negative/black powerlead of the radio,and oprobe the 4 or 5 pins of the mic socket with the other,the pin that buzzes on continuity or shows zero ohms on ohms scale is the ground pin,
if you don't have a multimeter trace the wires from the mic socket back to the circuit board,any that connect to the biggest solder track(its all over the board) is the ground wire or wires on a 5 pin socket. On the microphone the braided copper shield connects to this pin, that's you halfway to wiring the microphone,
now once you find this pin plug the radio back in,this is a cheap and dirty trick as I know your radio doesn't have a 13.8v pin,something you need to watch out for on 6 pin radios (on them first thing you do is set multimeter to volts range of 20 or over and connect the multimeter black wire to ground pin and use the red wire to probe the pins till you get the one reading voltage,usually 13.8v or thereabouts), ok back to your radio, with a short piece of wire connect one end to the ground pin you've already found to each of the other pins, the pin that switches radio to tx is transmit pin, the pin that gives rx noise is the rx pin, the other will most likely scream/squeal on a 4 pin socket (that's your audio pin) or do nothing if its a 5 pin socket,that's another ground pin,
in some radios two grounds were used one for audio return, the other for tx/rx common ground,some microphones are the same, either way on a 5 pin or 4 pin with only one ground pin socket soldering these two wires together will allow them to be put on same gnd pin.
Now if you've taken note of which pins do what in radio,always a good idea, it now time to find out which wires do what in the microphone,
guaranteed the wire that's wrapped inside the braided shield is the audio wire, it obviously goes to audio pin on radio, the braided shield is ground so obviously goes to ground pin on radio. Now that will either leave you 2 or 3 wires on most microphones (except those with ch up/dn buttons) if you have two wires left one is rx the other tx.if you have 3 wires left one is rx,one is tx and the other is rx/tx ground or switch common as showed on Robb's astatic guide. With the mike unkeyed on a 4 pin socket/4 wire mic try touching the one of the remaining wires to one of the remaining pins, if you get rx then you've found the rx wire and pin it goes too, if you get tx then your on the wrong pin,that wire goes to the other remaining pin and the last remaing wire goes to the pin that just sent the radio to tx,
if you have a multimeter and have 3 wires left, the best thing to do is try to find the wire that is common (shows continuity,buzzes or shows zero ohms) to either of the other two on tx and the other when unkeyed,that's your switch common/rx,tx common, its generlly doubled up with screen on 4 pin sockets and also on 5 pin sockets although you could use the other ground pin for it on a 5 pin socket.
You might find one of the remaining 3 wires isn't common too switching tx/rx, in that case its just an extra wire and can be cut short,this was often the case when manufacturers make a number of radios,some requiring 5 wires, some 4,its cheaper to buy in double the bulk of 5 wire ones and not use a wire th, it is to buy two seperate loads of 4 and 5 wire cables. In this case the other 2 will be rx and tx respectively.
On a standard dynamic mic,most old style mic's, the ohm reading between audio and ground will be roughly between 400 and 800 ohms as cb microphone input impedances are nominally about 600 ohms.
Finding the radio's ground pin is the key to success,as its common to all other functions.It can be easily be found with a multimeter or by sight with radio open.
Hope that helps,
If after wiring it still won't tx it could either be a break in tx wire,a tx switching transistor that's faulty, a dodgy output or/and driver or even a pll unlock condition, due to someone trying to add channels all of which are best left to someone that knows what they are doing.
