Technical Data Sheet
TEL-66T and TEL-66TRA
Dynamic Microphones
General Description
The Telex Model TEL-66T is a noise-cancelling aircraft communication
microphone. It consists of a dynamic microphone cartridge, transistor
amplifier, and push-to-talk switch in a rugged, black plastic case. A
hanger bracket and mounting hardware are provided with the
microphone.
The Model TEL-66T has a straight PJ-068 plug. The Model
TEL-66TRA is identical to the TEL-66T, except that it has a molded
right-angle plug.
The Models TEL-66T and TEL-66TRA are approved for aircraft use
under Federal Aviation Agency TSO C-58.
Specifications
Design Features
Noise Cancellation
The microphone provides best noise cancellation when the user holds
it very close to the mouth and speaks in a normal voice. The
microphone discriminates against all sounds more than ½-inch away.
A position at one side of the mouth is best to minimize popping,
hissing, and breathing sounds when speaking.
Microphone Gain Adjustment
The microphone gain is adjustable through an opening in the back of
the microphone using a
small, flat-blade
screwdriver. The
microphone is supplied
with an adhesive label
which may be placed over
this opening after
adjustment to prevent
tampering. Adjustment by a
qualified avionics
technician is recommended,
as excessive output can
cause transmitter overload
distortion.
38108-187 Rev H
Copyright
Type:
Close talking differential, dynamic element
Frequency Response
100-5000Hz
Impedance
50-600 Ω
Sensitivity
-48dB (re: 1V/μbar at 1kHz, ¼-inch from microphone with 150 Ω load and
12Vdc)
Supply Voltage
8-30 Vdc
Current Requirements
15mA at 12 volts, 100 Ω load
30mA at 24 volts, 100 Ω load
Switch
Microphone and relay circuits normally open
Cord
Three (3) conductor coil cord. 5ft (1.5m) extended length
Plug Type
Model TEL-66T: PJ-068
Model TEL-66TRA: Molded right angle (PJ-068 equiv)
Weight
9oz. (255 g)
Dimensions
See Dimensional Drawing on back
© Bosch Security Systems, Inc Printed in USA
8/2010
Diagrams
1.125 IN.
(28.58 MM)
PJ-068
2 IN.
(51 MM)
3.725 IN.
(94.62 MM)
2.54 IN.
(64.5 MM)
1 IN. (25.4 MM)
BETWEEN
MOUNTING HOLE
CENTERS
HANGER BRACKET
CORD LENGTH (EXTENDED)
5 FT (1.5 M)
Figure 1: Dimensional Drawing
(RED) MIC SIGNAL & +DC
(YEL) COMMON
(GRN) RELAY
MICROPHONE
CARTRIDGE
TRANSISTOR
AMPLIFIER
PLUG
RESPONSE (dB)
+20
+10
0
-10
-20
200
PUSH-TO-TALK
SWITCH
400
1000
2000
4000
10,000
FREQUENCY (Hz)
Figure 2: Wiring Diagram
Figure 3: Frequency Response (Typical)
Ordering Information
Model TEL-66T with PJ-068 plug ..............................................................................................................Catalog No. 60837-001
Model TEL-66TRA with right angle plug (equiv. to PJ-068) .....................................................................Catalog No. 60837-008
Replacement Hanger Bracket (supplied with mounting hardware) ............................................................Catalog No. 61506-000
Bosch Security Systems, Inc.
Bosch Security Systems, Inc. • 12000 Portland Ave South • Burnsvill e, MN 55337 • U.S.A
Specifications subject to change without notice