[ARC5] [Milsurplus] N-1 Carbon Mic Element and T-17s

[Clare Owens]

Hi Dave,

I was just able to win a "pile" of old Bell System headsets (4 of them)
from Will Donzelli and all 4 mic elements, apparently N-1s seem to work.
So I decided to see if I can salvage one of my T-17s.  The one I opened up
has basically no audio.  In your posting of last October 12 you mentioned
just hot melt gluing the N-1 into place - I guess without boring out the
hole where the original capsule was located???  Looks like there'd be room
in there for me to do that but I just wanted to check with you.  One other
guy talked about boring out the hole but I have no way to do that...

I have 7 or 8 T-17s and three RS-38s and only two of the T-17s had any real
audio when I just tested them with a 9V battery and a Bell speaker that
came in the "pile" and with this primitive setup I couldn't tell if the
audio would be usable.  Once I "convert" the T-17 I'm working on I'll wire
up the possibly good mics with a battery and an input transformer to the
line input of my little 60W amp one of these days and see about the
fidelity.


On Sun, Oct 21, 2012 at 2:40 PM, David Stinson <arc5 at ix.netcom.com> wrote:

> Re: Using T-17 mics.
> I've found exactly one T-17 that would deliver usable
> audio to a BC-456.  No amount of bashing or baking
> (or cussing) did any good with the others.
> So I temporarily hung a telephone element in the case,
> which does not fit inside but works, waiting for a better idea.
>
> Came across a few small carbon mic elements
> in round cardboard containers labeled:
> "ONE N-1 TRANS. UNIT"
> IIRC, these are used used in some 50s-60s handsets.
> I gave them a "table bump",removed the thick rubber
> moisture barrier and replaced it with light fabric,
> then hot-glued the elements in place of a couple
> of stone-dead and unrecoverable T-17 carts,
> with some "stuffing" behind to fill the chamber.
> To my surprise, through the small-diameter holes
>  in the T-17 face, these  elements delivered ample audio
> to a BC-456 modulator.  In fact, I can over-modulate.
>
> Are these elements available and at reasonable prices?
>
> TNX ES 73 DE Dave AB5S
>
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