The purpose of this tutorial is to give you the means to figure out which function each wire is serving when you don't know the color code. By the way when looking inside the radio, you can just as easily find the common or Ground by noting which pin the shield of that audio cable is attached to. For example, Cobra 4 Pin radios are wired 1 Shield 2 Audio 3 Transmit 4 Receive while Midland 4 Pin radios are wired 1 Audio 2 Shield 3 Receive 4 Transmit. Only 4 wires are needed but bigger sockets often mean that more than one pin may be grounded. For example, just because two different microphones are 4 pin does not mean that they are wired the same, even if they are the same brand! This works 99% of the time. Subsequently, a third-party market for 4-pin radio Microphones allowed for other companies to sell this Microphone under various brands - some listed above. This will work on most 4 wire mics.
Some older relay switched rigs used a small shielded cable between the mike socket and main chassis, a dead giveaway that those are the Mike line and Ground. Relay switched radios will be slightly more complicated, unless you have an older type that uses a 3-pin threaded mike socket. . Truckers Series by Barjan, Road-pro, High-Gear,Diesel and Truckspec. Made before 1994 dropped in 1999.
This leaves only pin 1 remaining, which must be the Mike line. If not, use the previously described Ohmmeter method. Content on this site may contain affiliate links. Some power mics leave the amplifier circuit connected to the radio audio pin. See the inset in Figure 3. Contact cleaner may solve the problem, but I've found it to be a temporary fix in most cases.
Note: As previously mentioned, many regular and power mikes come with a normally closed or shorted mike line. If need be, you can very gently spread the pins with a small flathead screwdriver. For example, the red wire on an Astatic mic is the Transmit wire, on Turner mics it's the common, and Cobra uses it for the audio lead. All Turner mobile mikes work this way. We will continue to try to get all the information that we can listed on this page. Make sure you lose continuity when you key the mic.
Different manufacturers may use a different way to wire microphone. Start by jumpering any two mike socket pins together and see what happens. You can also confirm this in Step 4 below. A quick Ohmmeter check after you find the mike line will reveal that you get a complete circuit continuity between the two remaining colored wires, rather than one color and the shield. The best way to determine the color code of a mic is to use and Ohm meter.
Feedback squeal is a very common problem. See the previous discussion to determine this. This is all right for most radios, the more expensive type in particular. As you look at the mic tip make sure the indent on the mic is as it is the diagram. If you make a purchase, My radio lab may receive a small commission at no additional cost to you. Touch the other Ohmmeter test probe to all the mike socket pins.
Prewired for 4-pin or 5-pin radios for Uniden and Cobra. You may also see this in the unkeyed position. This has the 4-pin plug wiring - look closely to where the grommet is, you will see a yellow sleeve over two wires soldered together at this area. Hey my mic only has 4 wires! One color should show a short; i. Generally it's not worth the trouble.
In these rare cases, there will be voltage to ground on two pins instead of just one; touching either of those pins to common will make the lights go out or blow the fuse. Step 2: Then with the mic keyed and one meter lead on the remaining wire connect the other meter lead one at a time to the 2 wires found in step 1. This indicates a normally closed audio line, a very undesirable feature. Be able to neatly solder and insulate those wires on the corresponding pins of the new plug. I dont know what happened to the mic i used to have for it, its long gone. Many new radios have the same connectors and wiring but some mics will work on all radios and others only work on some.
Step 1: Identify the Mike or audio line. The actual numbering for the pins on the Galaxy 4 pin mic connector is as indicated below in the diagram. I've seen mics from the manufacturer use the white or red wire for the audio connection while the blue wire was shielded. I also have a trick or two you can do this Circuit Design to improve the performance and level sensitivity, and hopefully, you're enjoyment. The only way to fix this problem is to put another set of contacts in to switch the audio lead. I hope you find this information as valuable as I have. In other words, this is the Ground.
Now attach a clip-lead or a piece of bare wire to the common pin you found in Step 2. Different manufacturers may wire their microphones differently. To begin, figure out which pin on the mike socket does what. The global market has made consumer products less standard than ever. Have you ever had trouble with wiring a stock mic? Mark it on your sketch.