Building Microphone from Capsule. Scratch Build Power ??? 4V Bias

[Onelasttime]

So I do not need 48V Phantom Power but I do need a 4V bias. Either way resistor and cap action is the order of the day. Should I wire up a pin on the radio's mic connector for 5,8,12 V what ever is the lowest choice? Should I wire it to work with a pre-amp and take it's 4V from 48V phantom supply? It has a 3 wire set up with separate wire for 4V bias. It is a large diaphram mic capsule.

The freq. response is more that what I need for radio 20Mhz to 10Khz powered large diaphragm condesnor. It was prob. intended for a kick drum because sensitivity is not that great and spl rating is pretty high. I got them at a really good price point.

I have modified microphones before but never actually built one from the capsule up. Thinking about wielding up some tubes and sending them out for platting to give it a high end vintage look when done with out the sand cast body and such. I have not sand cast anything since middle school in 1987-ish....LOL I made brass knuckles oh to aspire to greatness. LOL I am sure I thought I was cool at the time.

In my mind the easiest thing to do is power up a pin but feeding a radio with that much mic seems like a waste of mic on a stock radio. Might as well have a $2000 tube mic on a stock cobra 19.....LOL If I go the other route I decide to set it up with a preamp/mixer the next logical step is to try direct inject and e-SSB.

I know all of this because I could not say NO to a great deal on something I really did not need! LOL

 

[rabbiporkchop]

So I do not need 48V Phantom Power but I do need a 4V bias. Either way resistor and cap action is the order of the day. Should I wire up a pin on the radio's mic connector for 5,8,12 V what ever is the lowest choice? Should I wire it to work with a pre-amp and take it's 4V from 48V phantom supply? It has a 3 wire set up with separate wire for 4V bias. It is a large diaphram mic capsule.

The freq. response is more that what I need for radio 20Mhz to 10Khz powered large diaphragm condesnor. It was prob. intended for a kick drum because sensitivity is not that great and spl rating is pretty high. I got them at a really good price point.

I have modified microphones before but never actually built one from the capsule up. Thinking about wielding up some tubes and sending them out for platting to give it a high end vintage look when done with out the sand cast body and such. I have not sand cast anything since middle school in 1987-ish....LOL I made brass knuckles oh to aspire to greatness. LOL I am sure I thought I was cool at the time.

In my mind the easiest thing to do is power up a pin but feeding a radio with that much mic seems like a waste of mic on a stock radio. Might as well have a $2000 tube mic on a stock cobra 19.....LOL If I go the other route I decide to set it up with a preamp/mixer the next logical step is to try direct inject and e-SSB.

I know all of this because I could not say NO to a great deal on something I really did not need! LOL

Hard to believe nobody on this forum hasn't done this.
Here is a cool project to try.
http://www.w1aex.com/mic/mic.html
My Anytone AT-6666 has 5 volts on the audio wire already, so it's easy to wire them up on my radio.

 

[unit_399]

. It is a large diaphram mic capsule. The freq. response is more that what I need for radio 20Mhz to 10Khz powered large diaphragm condesnor.

Interesting mic element that has rf output at 20 MHZ.

- 399

 

[rabbiporkchop]

Look in the hardware section at Lowe's and dig through the drawers and you'll find a nylon spacer and they come in many different sizes with many sized holes in the middle and match one up to the body that you plan on putting it in along with the hole that matches the diameter of the capsule itself.

 

[Onelasttime]

Yes fitting my NOS high-end European built capsules into an off the shelf mic for RF hobby is going to be hard unless I fab. the entire mic body and all. The capsules I am using were built back before 48v phantom power was the norm. When they were made each company provided their own power supply and matching network. It was like the Wild West back then! They are very deep!

I do have some hi end miltary spec. tiny electrets I can play around with and those are tiny like the size of a watch or hearing aid battery!

 

[rabbiporkchop]

The 10mm electret capsules fit perfectly in these nylon spacers I bought from Lowes. The capsule just presses Right In and stays put.