INCH-POUND
MIL-PRF-25670/2C
30 May 1997
SUPERSEDING
MIL-E-25670/2B(USAF)
20 FEBRUARY 1980
PERFORMANCE SPECIFICATION SHEET
EARPHONE ELEMENT,
HIGH- AND LOW-ALTITUDE, H-143/AIC,
AND LOW-ALTITUDE, WATER-IMMERSIBLE, H-143A/AIC
This specification sheet is approved for use by the Department of the Air Force, and is
available for use by all Departments and Agencies of the Department of Defense.
The complete requirements for procuring the earphone element described herein shall consist
of this document and the latest issue of MIL-PRF-25670.
.093 DIA, .188 MIN DEPTH
.161 DIA MIN
SET-SCREW (2 REQD)
(CLEARANCE IN METAL
SEE NOTE 2
HOUSING) - 2 HOLES
IDENTIFICATION
1.800
+ .020
- .015
1.986
+ .000
.720 MAX
- .015
BREATHER.
SEE NOTE 3.
.020 MAX
SEE NOTE 4
.400 MAX
SEE NOTE 6
.109 ± .015
.915 MAX
.440 + .025
- .020
SOUND APERTURES
MUST BE LOCATED
IN THIS AREA. SEE
NOTE 5
NOTES:
1. Dimensions are in inches. Unless otherwise specified, tolerance is ± .010 in.
2. Screws shall be recessed, of type slotted or allen (for interchangeability of spares), and shall securely
hold the next-higher-assembly headset-connector pins, preventing inadvertent disconnection.
3. Use of, quantity and location of breather hole are optional. See Requirements.
4. The raised, central portion of the front cover is optional only in the H-143A/AIC.
5. All outer dimensions shall ensure a firm positioning of the element in standard earcup foam filler
material (depth, contour, ear-position), as well as within the standard earcup retaining-ring.
6. Cable-connection holes shall be positioned within reach of standard-length headset cabling.
C FIGURE 1.
Earphone elements, H-143/AIC, and H-143A/AIC.
C denotes changes
AMSC N/A
1 of 5
FSC 5965
DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited.