Ultimate Computer Microphone Conversion

Intro: Ultimate Computer Microphone Conversion

This Instructable will show you how to convert an old CB radio microphone (Astatic D104) into a computer microphone.

You can get these high quality chrome plated brass microphones at yard sales and on E-bay for very little cash. I chose this type of "lollipop" microphone because to talk you simply squeeze the neck and it turns on. It also has a locking ring to lock it in the on position. its also very sturdy being all metal and to me has that "retro" look.

Their are also several different kinds you could choose to convert as well, its a simple operation.

Your computer will not be able to drive the old CB microphone element very well, so we will replace it with a store bought one.

Next up parts and tools.

STEP 1: Parts, Tools and Supplies Needed.

Parts
Astatic D-104 Microphone or similar. (below are some other types you could convert)
One computer microphone with cord (everything you need to upgrade in one package)

Tools and supplies
Screwdrivers
soldering iron with solder
spray paint
1/4" heat shrink tube
Volt/ohm meter
Epoxy
small saw

NOTE :should you find another type of microphone to convert, check Ebay for its current market price, you could have one worth allot of cash. An example is a microphone that looks just like the one being converted here, but its gold plated and has an eagle on the back of the head. This is the Golden Eagle version made in the seventies, worth a few hundred bucks!
So be smart and research before you convert.

STEP 2: Getting the Microphone Base

I started by taking the base apart and cleaning it.

Take off the base plate by removing the three screws.

This one had an old circuit board and a badly leaking 9v battery this was the pre-amp.

I simply cut that out and left any wire that was running up the neck as long in length as I possibly could. Some of these wires will be used in the conversion.

The old cord was held in place by a clamp, this was loosened and the old cord was discarded.

The base was painted dark tan but was very scratched, so it was sanded and painted with Krylon "hammered" paint. This makes a strong hard finish that has that "equipment" look and feel.

The rest of this microphone is chrome so it was cleaned and polished.

STEP 3: Getting the Microphone Housing Ready.

The D-104 has four screws holding the face and back plates on.
It looks like mine had been dunked in water a few times, so allot of cleaning was done.

The only thing inside of the Microphone head I kept was the black fabric and the windscreen, this was used to keep the user from making popping sounds.

Depending on what computer microphone you end up using you may or may not need this.

STEP 4: Taking Apart Your Plastic Computer Microphone

Now take apart your computer microphone I used a fairly cheap one so all that was required was to pop off the front and saw a small slit in the side and force it apart just enough to get the condenser microphone out.

After you get it out, cut the cable leaving an inch of wire on it.

STEP 5: Mounting the New Microphone

After you take apart the top of the Astatic you will notice that it has nothing to mount your new condenser to.
You can use a piece of cardboard cut to fit or if you have some thin balsa laying around from another project like I used its soft and easy to glue.

I started by using the microphone head for a template and cut two wooded circles, one for the back and the other one to be cut in half and used as a sound guide.

I used super glue and epoxy to hold all in place.

STEP 6: Mounting the New Microphone Continued

Now solder the new condenser microphone to the two wires in the microphone head.

The Astatic microphone has a removable head so you will need to make sure of polarity the insulated wire in the two conductor cable is the positive the other the negative.

Be sure to use the heat shrink and if your using cardboard make sure that the wires never touch the metal housing, this will make a nice buzz when you touch the microphone.

Glue everything down with epoxy.

Drill four holes for the screws and reassemble the head.
I used the foam black wind screen that came with it to cut down on pops and crackles.

STEP 7: Wiring the Base

Remove the neck from the base and take the switch out,

You will notice that two wires run to the plug on the top, if you want a microphone thats always on, just wire your cord to these.

If you want it so that you can switch it on and off like the original, use a couple of the connectors on the switch to break the connection of the positive lead.

I also cut off all the wires that were not to be used, If you wanted you could use the switch to activate something else, you could build some voice effects into the base and use the other contacts to activate it...

Also pictured below is a simple wiring diagram.

STEP 8: Wiring the Base Continued

I used the bottom set of connectors on the switch, that way when you squeeze the handle it comes on, you could use the other connectors and make it work the opposite way.

After you decide what switch you will use connect the negative wire to the cable and the positive from the condenser microphone to the switch, then from the switch to the cable, completing the circuit.

Reassemble the base as shown.

STEP 9: Finished

You now have a computer microphone that will last for years and looks great to.

Hope you enjoyed this conversion thanks for reading,

Zachary M,
Clinton, TN

Comments

[FredK32]

What are you doing with the guts that you are taking out of these microphones? If you are trashing them, I would buy them from you.

[decosoced]

So, I have the head to a d104 astatic, but the stand didn't come with it. in addition, the wires from the connector on the base of the head aren't even connected to the mic inside the unit. Any suggestions on where i can find a body and a diagram to reconnect the mic inside the head?

[nickademuss]

Thing was submerged in water, the electronics where gone, the diaphragm was wasted and guess what I am an electronics engineer if I could of revived it I would of, I have two others a regular one and the GOLDEN eagle, those work very well on my SW rig.

[TruckCenrtal]

I don't understand why people don't read thread b4 commenting.. I think it is awesome that you re purposed this surly trashed mic. I am interested in making my Silver Eagle work on my computer. But I don't want to cut it up. Any suggestions how to do so with it being a battery powered mic? I am willing to change plug but no further internally.(unless i am left with no other option.) I would even be willing to make a box with cb type female plug input and regular puter mic plug output if you had an idea for proper wiring.

[riverreaper]

i did et mine to work with the computer but i run it threw a mixer an that runs into a outside the computer sound card type box called AUDIOBOX USB by presonus ,...but you probly could just wire it to a female plug thats wired to the type of plug you need , or even into a box with many types of plug outs . i rarley use mine anymore .

[nickademuss]

its been a long time since I had a good working one, I think you can get a signal out of two of the four pins on your working rig, You could get a socket from the shack, or online and keep the original cable, then make a small adapter to go from CB 4pin to 1/8 plug... That what I would try :)

[k.ghia]

Excellent work, I suck at electronics/electrical stuff but I would give this a shot. It would be a cool piece to have if I actually got it to work. Chances are not good.

[sctirvn687]

To connect this to the sound card, wouldn't it need to have a stereo plug on it with the positive connected to both left and right channels?

[nickademuss]

I used a cable from an old computer microphone, and yes if you use your own the positive is the tip and negative is the back or outer connectors. You can tie the positives together if your not using a stereo mic. 

[your_dragon113]

*Gasp* @Shocked Look@... That's just sacrilege! (((still gasping...holding my chest)))...That's a D-104 there man...That's right up there with the Silver Eagle and the Golden Eagle... ((( *calling for a Crash-Cart* ))) It IS a very nice mod and I DO understand why you did it, being a CBer and Hmmie myself...but..but.......a D-104??? *crying*

[nickademuss]

Awww, it had a good life before it was soaked in water and ruined. The electronics had grown fuzz and the whole thing had to be cleaned out. I saved it from never being used again. Its used now on a regular basis....

I would never destroy a working one, I would Ebay it!

[tpsbpl]

Inexpensive Homemade Computer Microphone
http://onlinetps.com/computer_mic.htm

[tpsbpl]

Inexpensive Homemade Computer Microphone
http://onlinetps.com/computer_mic.htm

[Bigev]

If you happen to not have a working computer mike at all, a typical phone has the same type of microphone. (check goodwill, they're cheap) Just rip it out and there ou go. Plus, if you have a working mike, you just got bonus! Plus Plus, the phone comes with a rather good speaker as well. Plus Plus Plus, please explain, what is a base connector?

[nickademuss]

this mic has a removable base, with a two pin connector...

[Bigev]

Wait, so is it a component part that is essetial to the mic? Like an amplifier or something else, or is it just a plug? I'm a tad confused.

[nickademuss]

its a plug that is on this type of microphone, sorry for the confusion. They made it removable from the base.

[Bigev]

Ahhh... so it's that easy then... I'll be making one! Thank you!

[Dr.Bill]

How do I adapt this to my Kenwood TM-231A ?

[nickademuss]

I would find a working one and leave it alone for that application. Nice radio!