help with using utc a24 in a u47 type circuit

I'm a new be at these tube mic diy.  I started a u47 circuit mic and would like to use a utc as the output transformer.  I could use some help with which pin are best used in the circuit.  Any help would be good.

thank you for your reply.  This is my first posting so it is kind of exciting.  I know i will need to wire the transformer backwards like done in Royer 2 mod on a mxl 603s.  In the first version of "church u47" a utc a24 was used, so i know it can be done.

I think the OP is confused... A mic INPUT transformer would need to be wired backward, yes, but not a 15k:600 OUTPUT transformer. You could just wire that up and go. That's a 5:1 stepdown, about the same ballpark as the g9...I believe the bv08 transformer in the u47 was something like 6.5,6.5:1,1 so it could be 6.5:1 or 13:1. I think most are wired for 6.5:1, but don't quote me on that.

Thank you gemini86, your post clears a lot.  Yes your right the country boy's capacitor mic by Royer uses that jenson mic input trany, dont know why i thought it was an output trany.  I can read a schematic so i'll go with standard wiring with the A24 in my mic.  I'm now curious about wiring an utc a24 in a 13:1 way.  If this is possible that would make sense why Stanley Church started with the UTC a-24 and a 6072 tube.  This is my next mic i plan to build after this one.

Are the hookup options printed on the case? it should say for 200ohm output join 3 to 4, use 2 and 5 for output which are taps of each secondary winding. So the two partial sections of the secondaries wired in series for 200ohm. 15k to 200 is about 9:1 ratio and in theory should work well. Will it fit in the body you're using?
Matt

Are pins 2 and 5 center taps, or some other tap? I don't have the full data in front of me, just CJ's winding sheet.

Ok further down cj's dissection I see that they are not exactly center taps, so 200ohms out sound about right.

Here is a pic of the A-24 winding diagram.

http://i1257.photobucket.com/albums/ii520/earlfsmith/UTCA-24.jpg

If you can further explain what would be right wiring for the u47 mic.  I'm looking to do in the ballpark of the BV8 standard 6.5:1 setup.  Thanks

Them hook it up as it says. Primary 15k secondary 500.

I am now understanding the wire diagram on the transformer but what i am confused about is that i should the omhs be coming out of the trany?  500 ohms or 200 ohms?  Keep in mind i am new at this and have not learn the correct math yet.

> what would be right wiring

The real issue is that A-24 is way bigger than a mike needs, awful big for something so close to a precision sound sensor. Also now irrationally over-priced.

Use the 200 connection. The Z to the head-amp side can be high, the Z to the mike line should be low.

Thank you PRR, this is exactly what i was looking for.  Everybody that i've talked to about using this trany with the mic as looked at me crazy.  ??? I just like to hear it and compare it to other tranys that are out there in DIY's.  Thank you everyone for your replies.

you can take it out of the can so it will fit in the mic body,

CJ said:

you can take it out of the can so it will fit in the mic body,

Click to expand...

or send it to cj and he can take it all apart

let me warm up the heat gun, 

I have a friend that wanted to do that but i rather keep it in so i can pop it in a diy la2a without having to call him up.  Plus i am to afraid to do it myself that i might kill the trany all together.  But good suggestion and thanks CJ for being willing.  :-X  I'm using a nady 1050 mic and extended it with a muffler.  It was easier than i thought i would be to alter it.  Hear are a couple of pics.

http://i1257.photobucket.com/albums/ii520/earlfsmith/U47MicBody.jpg

http://i1257.photobucket.com/albums/ii520/earlfsmith/U47MicFrame.jpg

Good work!

I was picturing something like this when you said muffler...

Ha ha ha!!!!! Too funny gemini86 but then again i probable would have thought the same thing.

gemini86 said:

Good work!

I was picturing something like this when you said muffler...

Click to expand...

Just don't use glass packs, too much self-noise. 
Nice work on the new rails earl. Did you use a saw, or snips and mallet them flat?

I picked up this meddle strip that looks like a V when you look straight at it from Home Depot.  From the side of it it looks like a the blade on a slim jim.  I think it was about 3 feet long.  I plan to build another mic soon, i pick up another one i'll take a pic of it and post it.  What i did was used a grip and cut it at the tip of the V point to made it into two strips.  Then with the Grip i trimmed it down to the size i wanted.  I used the Grip to cut the muffle tip also.  I pick the muffler tip up from Auto Zone.  It was the same size as the stock nady body.  I used the Grip to shave down the side that was to connect to the mic basket or what ever you call it.  I didn't buy a muffler like in your picture.  I bought one of thoughts chrome tips that you put on the end of the muffler so it looks nice.  I'm not sure what glass packs are but i assume that has something to do with a type of muffler like the one in your pic.