[Milsurplus] T-17 Rebuild

[Jim Whartenby]

Has anyone looked into putting the complete T-17 microphone into a container and pulling a vacuum on it to see if the years of moisture can be safely removed from the carbon element?  
I've converted an old pressure cooker into just such a container and can pull better then 25 inches of Hg which seems to do the job of removing years of moisture contamination from the SMO of a KWT-6 or URC-32.  
A vacuum of 25 inches of Hg for half a day seems to work OK.  A 1/8 inch ball valve will hold the vacuum for days so the vacuum pump only runs for a few minutes.  All of the hardware and plastic tubing was bought at Lowes.  All of the needed holes were already in the lid.  A new pressure cooker gasket was less the $15.
Jim
Logic: Method used to arrive at the wrong conclusion, with confidence.  Murphy

-----Original Message-----
From: B. Smith <smithab11 at comcast.net>
To: Milsurplus <milsurplus at mailman.qth.net>
Sent: Tue, Jul 19, 2022 11:25 am
Subject: [Milsurplus] T-17 Rebuild

         Several have asked about replacing the carbon microphone element  in the T-17. I usually use a standard telephone button and trim it to fit inside the T-17 housing by removing the outer frame. The button then fits inside the T-17 housing and the outer cover  with the small center holes can be fitted. (Drill additional center holes if necessary to improve voice response) Other have taken a T-17 housing and machined the interior  to  enlarge it to accommodate the larger button but removing the outer frame  with a small file is faster and easier.  There is no compassion between the audio output level between the original T-17 cartridge which has aged and the telephone button, the button  is loud and very crisp. See attached photo.
          Info on the T-17 including the button mod,capacitor info, rewiring etc can be found at  the link below. In addition there is a chart supplied by WA5CAB on the different  contract dates and manufacturers  of which  I've added a couple of entries. I will add additional info to the chart if I receive the information. 
 k4che
 http://k4che.com/T-17/T-17.htm
 
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