Hi Ken

Thanks for the info. I suspected the case on the D was one piece, but wanted to check before I tried to pry them apart.

73 Mark K3MSB

On Tue, Aug 11, 2026 at 7:54 PM Ken Kinderman <[email protected]> wrote:

The T-17 D is a real pain. From my experience, the two screws on the bottom are just for cable strain relief. The element is easy to get to. But by destroying one, I discovered that to gain access to the switch (if needed) you need to unscrew the black button from the large knurled ring. No matter how I try, I just can ‘t do it.

The case itself is one molded part, not two pieces glued together, unless you found differently.

Anyway, that’s my experience.

I have 86’d more -D’s than I have saved

Ken
W2EWL

> On Aug 11, 2026, at 7:41 PM, Mark K3MSB via Milsurplus <[email protected]> wrote:
>
>
> As reported a few months ago, my trusty T-17 mic with replacement mic element suffered an internal breakage, fortunately at the very end of the Reading Air Show.
>
> A very kind fellow sent me a box of old carbon mics, one of which was a T-17-D. He said the audio was very low, and indeed it was.
>
> Today, just for fun, I disassembled the mic element. Some of the carbon grains were indeed clumping. I removed the grains and put them under a 60W lamp for several hours.
>
> <image.png>
>
>
> I reassembled the mic and the audio is better, but still low. I had no idea how to put the grains back in, so I just filled the little bowl (top in the above picture).
>
> One half of the T-17 mic (that has the busted internal part) can easily be removed via 3 screws.
>
> The T-77-D that I worked on today has only two screws at the base of the handle, on opposite sides of the mic. I can see no way to access the inside of the mic, unless you remove those two screws and yank the two halves of the mic apart.... and I thought I'd check before I did any yanking as the two halves appear to be bonded.
>
> Have any of you done this?
>
> Resistance has dropped from 50K or so to between 2K and 9K. Still very high than the several hundred ohms I'd like to see, but better than 50K. I think the varying resistance may be due to needed cleaning of the switch.
>
> In any event, if I can get the shell open, this D variant will be seeing a replacement mic element in its future.
>
> 73 Mark K3MSB
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