Sennheiser HME 46-3 User manual

SA 070401
Subject to alterations
Sennheiser electronic GmbH & Co. KG • 30900 Wedemark, Germany
Phone: [phone] • Fax: [phone]
Air Traffic Control
HME 46-3
HMD 46-3
Service manual
Revision
02/2008
Short description
This headset features dynamic, open headphones. The noise-compensating
microphone ensures excellent speech transmission even in noisy
environments. Designed for air traffic control, intercom systems and other
communication purposes.
Features
•ActiveGard™ (not HME 46-31 and HMD 46-31)
•“Flip-away“ earcup
•Automatic two-piece headband
•Flexible microphone boom can be worn on either left or right-hand side
•Single-sided cable
•Comfortable wearing earpads
•PTT button integrated in the cable (HME/HMD 46-3PTT-x only)
Product variants
500857 HME 46-3
500467 HME 46-3-6
500874 HME 46-3PTT-M
500468 HME 46-3PTT-6
500469 HME 46-3PTT-L
502172 HME 46-3PTT-LA
500851 HME 46-ATC
502484 HME 46-31
500849 HMD 46-3
500466 HMD 46-3-6
500873 HMD 46-3PTT-M
502483 HMD 46-31
502594 HMD 46-3(5)
Cable variants
500836 -6
502360 -7
502365 -L
500844 -PTT-6
502418 -PTT-6-1
500845 -PTT-L
502187 -PTT-LA
500930 -D-3PTT-M
500931 -E-3PTT-M

HME 46-3, HMD 46-3
2/25 02/2008
Safety requirements
Observe safety regulations.
Observe ESD instructions while handling electrostatically endangered components.
Only skilled persons are allowed to alter and repair. For repairs and exchanges only
approved components according to the current spare parts list are allowed.
For safety and certification reasons it is forbidden to alter the product without
authorization. Otherwise, the person who has altered the product is liable for any
consequential damage.
repairs/exchanges The following instructions for overhaul and testing must be followed.
In case of unusual problems please contact your Sennheiser distributor.

HME 46-3, HMD 46-3
02/2008 3/25
Contents
1 Outline dimension ..........................................................................................5
2 Technical Data.................................................................................................6
2.1 Headphones........................................................................................................... 6
2.2 Microphone of HMD 46-3.................................................................................... 6
2.3 Microphone of HMD 46-3(5) .............................................................................. 6
2.4 Microphone of HME 46-3 (with preamplifier) ................................................ 6
2.5 General data .......................................................................................................... 6
3 Disassembly ....................................................................................................7
3.1 Removal of the cable ........................................................................................... 7
3.2 Disassembly of the cap........................................................................................ 7
3.3 Disassembly of the cable .................................................................................... 7
3.4 Disassembly of the microphone arm ................................................................ 8
4 Assembly .........................................................................................................9
4.1 Assembly of the cap............................................................................................. 9
4.2 Assembly of the -PTT-x cable............................................................................. 9
4.3 Assembly of the cable to the headset............................................................ 10
4.4 Assembly of the microphone arm ................................................................... 10
5 Testing and fault isolation......................................................................... 11
5.1 Tools and test equipment................................................................................. 11
5.2 Operational test of the audio system............................................................. 11
5.2.1 Audio testing the headset with cable ............................................................ 11
5.2.2 Operational testing of the pre-polarized microphone
at the headset with cable (HME 46-3-x only) .............................................. 11
5.2.3 Testing of the dynamic microphone
at the headset with cable (HMD 46-3-x only).............................................. 12
5.2.4 Operational testing of the headset cables .................................................... 12
5.2.5 Audio testing of the headset without cable ................................................. 12
5.2.6 Testing of the ActiveGard™ of the PCB (not HMD/E 46-31)...................... 13
6 Wiring diagrams .......................................................................................... 15
6.1 Wiring diagram for cable -E-3PTT-M, -D-3PTT-M......................................... 15
6.2 Wiring diagram for cable -PTT-L...................................................................... 16
6.3 Wiring diagram for cable -PTT-6 ..................................................................... 17
6.4 Wiring diagram for cable -PTT-LA................................................................... 18
6.5 Printed circuit boards ........................................................................................ 19
6.6 Block diagram...................................................................................................... 20
7 Exploded views with spare part lists........................................................ 21
7.1 Exploded view HME 46-3 / HMD 46-3............................................................ 21
7.2 Spare part list for HME 46................................................................................. 22
7.3 Spare part list for HMD 46 ................................................................................ 22
7.4 Exploded view of the system module ............................................................ 23
7.5 Spare part list of the system module
not microphone side (525764) ....................................................................... 23
7.6 Spare part list of the system module
microphone side (525763)...............................................................................23
7.7 Exploded view of the cap, microphone side .................................................. 24
7.8 Spare part list of the cap, microphone side................................................... 24
7.9 Exploded view cable -PTT-x .............................................................................. 25
7.10 Spare part list for cable -PTT-x ........................................................................ 25

HME 46-3, HMD 46-3
02/2008 5/25
1 Outline dimension
1
2
Cable type Complete cable length
-PTT-6,
-PTT-6-1,
-PTT-L
1.85 m
-PTT-LA 2.30 m
-E/D-3PTT-M 2.45 m
-7,
-ATC / -L
2.00 m
Cable type Length of Length of 
-E/D-3PTT-M 0.80 m 1.60 m
-PTT-LA 0.50 m 1.75 m
-PTT-L, -PTT-6 1.50 m 0.30 m
-PTT-6-1 0.80 m 1.00 m

HME 46-3, HMD 46-3
6/25 02/2008
2 Technical Data
2.1 Headphones
Transducer principle_______________________ dynamic, open
Ear coupling _____________________________ supra-aural
Frequency response _______________________ 20 to 14.000 Hz
Impedance _____________________________ 300 ohms per system
Sensitivity
HMD/E 46-3 _______________________ 95 dB/SPL at 1 kHz, 1 mW mono
83 dB/SPL at 1 kHz, 1 V
HMD/E 46-31 ______________________ 95 dB/SPL at 1 kHz, 1 mW mono
103 dB/SPL at 1 kHz, 1 V
THD
HMD/E 46-3 _______________________ < 1 % at 95 dB SPL (350 to 3.000 Hz)
HMD/E 46-31 ______________________ < 1 % at 110 dB SPL (350 to 3.000 Hz)
Contact pressure _________________________ aprx. 3.0 N
2.2 Microphone of HMD 46-3
Type _______________________________ MD 46-413
Transducer principle _____________________ dynamic, noise compensating
Frequency response______________________ 100 to 12.000 Hz
Output voltage _________________________ 0.5 mV/Pa
Impedance ____________________________ 200 ohms
2.3 Microphone of HMD 46-3(5)
Type _______________________________ MD 46-413_5 ohms
Transducer principle _____________________ dynamic, noise compensating
Frequency response______________________ 100 to 12.000 Hz
Output voltage _________________________ 0.125 mV/Pa
Impedance ____________________________ 5 ohms
2.4 Microphone of HME 46-3 (with preamplifier)
Type _______________________________ MKE 46
Transducer principle _____________________ pre-polarized condenser microphone, noise compensating
Frequency response______________________ 350 to 6.000 Hz
Output voltage
HME 46-3, -3-6, -3PTT-M,
-3PTT-6, -3PTT-L, HME 46-31 __________ adjustable from 17 to 100 mV/Pa,
80 mV/Pa (factory pre-set) ≅ 800 mV at 114 dB SPL
HME 46-3PTT-LA, -ATC adjustable from 17 to 215 mV/Pa,
152 mV/Pa (factory pre-set) ≅ 1520 mV at 114 dB SPL
Terminating impedance___________________ 150 to 2.200 ohms
Supply voltage _________________________ 8 to 16 V DC
2.5 General data
Ambient temperature
operating mode ___________________ -15°C to 55°C
stocking _________________________ -55°C to 70°C
Weight, without cable ____________________ aprx. 150 g

HME 46-3, HMD 46-3
02/2008 7/25
3 Disassembly
3.1 Removal of the cable
Reference:
•see “Exploded view HME 46-3 / HMD 46-3”, page 21.
1. Loosen the screws of the cable.
2. Remove the cable from the cable holder (110).
3.2 Disassembly of the cap
Reference: see “Exploded view HME 46-3 / HMD 46-3”, page 21.
1. Remove the earpad (90) from the relevant cap (20 or -25).
2. Lift the sides of the discs (80), now the screws (70) are visible or remove the discs (80) from the
caps (20 or -25) completely if necessary.
3. Remove the screws (70).
4. Pull out the the resonator (60) with capsule.
5. Remove the center (50).
6. Remove the felt plate (40).
7. Unsolder the leads of the cable (TP1 to TP4) of the split headband (10) from the PCB,
see “Printed circuit boards”, page 19.
8. Unsolder the leads from the capsules (TP8, TP9), see “Printed circuit boards”, page 19 or see “Exploded
view of the system module”, page 23.
9. Unsolder the cable from the microphone arm (100 or -105) (TP5 to TP7)*.
10. Remove the cable holder (110) from the cap (20)*.
11. Remove the cap (20 or -25) from the split headband (10).
3.3 Disassembly of the cable
Reference: see “Exploded view cable -PTT-x”, page 25.
1. Remove the four screws (40) of the housing (10).
2. Open the housing (10, 30).
3. Remove the inserts (50).
4. Take out the PCB (60) and the cables (90, 100) of the housing (10).
5. Desolder the cables (90, 100) from the PCB (60).
* Only microphone side.

HME 46-3, HMD 46-3
8/25 02/2008
3.4 Disassembly of the microphone arm
Reference: see “Exploded view HME 46-3 / HMD 46-3”, page 21 or see “Exploded view of the cap, microphone
side”, page 24.
1. Rotate the microphone arm (100 or -105) to the side position if necessary (see figure below).
2. Screw the threaded pin (10 of the cap module) completely into the microphone arm fixing .
3. Disassemble the microphone arm (100 or -105) from the cap (20) by moving the microphone down
towards to the other cap (-25) of the headset .


100
20
10 (of the cap module)

HME 46-3, HMD 46-3
02/2008 9/25
4 Assembly
4.1 Assembly of the cap
Reference:
•see “Exploded view HME 46-3 / HMD 46-3”, page 21.
1. Attach the relevant cap (20 or -25) to the headband (10).
2. Solder the relevant leads of the split headband cable to the PCBs (TP1 to TP4), see “Printed circuit boards”,
page 19 and see “Block diagram”, page 20.
3. Solder the microphone cable (TP5 to TP7) at the microphone arm PCB, see “Printed circuit boards”, page 19
and see “Block diagram”, page 20.
4. Put the center (50) over the resonator (60) and solder the orange and brown leads at the relevant pins
(TP8 and TP9) to the PCB , see “Printed circuit boards”, page 19 and see “Block diagram”, page 20.
5. Install the felt plate (40) on the PCBs (20 of the system module).
6. Turn the center (50) into the cap (20 or -25).
7. Set the capsule with resonator (60) into the cap (20 or -25).
8. Install the screws (70) with a torque of 25 Ncm ±3 Ncm.
9. Install the label (120) on the cap (-25), if applicable.
10. Install the disc (80) on the resonator (60) if necessary.
11. Install the earpad (90) over the disc (80) on the cap (20 or -25).
4.2 Assembly of the -PTT-x cable
Reference: see “Exploded view cable -PTT-x”, page 25
1. Solder the cables (90, 100) at the PCB (60), see “Wiring diagrams”, page 15 et sqq.
2. Install the PCB (60) with the cables (90, 100) into the housing (10).
3. Close the housing (10) with the cover (30).
4. Install the inserts (50) at the top of the housing (10).
5. Fasten the screws (40) of the housing (10) with a torque of 25 Ncm ±3 Ncm.
* Only for microphone side.

HME 46-3, HMD 46-3
10/25 02/2008
4.3 Assembly of the cable to the headset
Reference:
•see “Exploded view HME 46-3 / HMD 46-3”, page 21.
1. Set the connector of the system cable into the cable holder (110)*.
2. Fasten the screws of the system cable with a torque of 25 Ncm ±3 Ncm.
4.4 Assembly of the microphone arm
Reference: see “Exploded view HME 46-3 / HMD 46-3”, page 21.
1. At the inside of the microphone arm fixing is a latch . Firstly set this latch at the right socket
position  of the cap (20).
2. Hook the microphone arm (100 or -105) into the cap (20).
3. Fix the microphone arm (100 or -105) with the threaded pin (10 of the cap module) to outside. Turn the
threaded pin (10 of the cap module) out to exceed in the assembled condition 0.1 to 0.3 mm over the
surface of the microphone arm fixing.
* Only for microphone side.



PCB
PCB cable (inside)
20 100
10 (of the cap module)

HME 46-3, HMD 46-3
02/2008 11/25
5 Testing and fault isolation
5.1 Tools and test equipment
5.2 Operational test of the audio system
References
•see “Cable connector´s pin alignment”, page 14.
•see “Wiring diagrams”, page 15 et sqq.
•see “Printed circuit boards”, page 19.
5.2.1 Audio testing the headset with cable
1. Connect the sine wave generator with the negative and the positive line at the relevant pins of the
connector, see “Cable connector´s pin alignment”, page 14 or see “Wiring diagrams”, page 15 et sqq.
2. Set the sine wave generator to 300 mV eff ± 5 mV with a signal of 1 kHz and switch the generator on.
3. A clear signal without any distortion must be audible in both capsules.
5.2.2 Operational testing of the pre-polarized microphone at the headset with cable
(HME 46-3-x only)
A. Audio testing, see “Cable connector´s pin alignment”, page 14 and see “Wiring diagrams”, page 15
et sqq.
1. Connect the headset with the cable connectors into the intercom.
2. Put on the headset, adjust the microphone to the correct position and talk into the microphone.
3. Listen to the audio output signal. No distortion should be audible.
B. Visual testing
1. For detailed visual testing please use the ossiloscope, see “Microphone test setup according to RTCA/DO-
214”, page 14.
Description Specification / Type Source
Power supply U: 0-30V DC adjustable
I: ≥500 mAeff
Hum: <1%
Commercial
Sine wave generator AF Level adjustable Commercial
Multimeter U: 0-30V DC
I: ≥500 mAeff
Resolution ≤0.1 V
Commercial
Oscilloscope -Commercial
Intercom
Audio amplifier
-
Any audio amplifier with
high impedance micro
input
Commercial
Commercial

HME 46-3, HMD 46-3
12/25 02/2008
5.2.3 Testing of the dynamic microphone at the headset with cable (HMD 46-3-x only)
Reference: See fig. 1 “Operational test of the dynamic microphone” page 13
A. Operational testing
1. Connect the microphone connector of the headset with the negative and positve line into the
audio amplifier input, see “Cable connector´s pin alignment”, page 14 or see “Wiring diagrams”, page 15
et sqq.
2. Connect the headphone connector of the headset with the negative and positve line into the audio ampli-
fier output, see “Cable connector´s pin alignment”, page 14 or see “Wiring diagrams”, page 15 et sqq.
3. Connect the oscilloscope into a free amplifier output, see “Operational test of the dynamic microphone”,
page 13
4. Speak into the microphone of the headset:
- The speaker´s voice will be audible without any distortion in both capsules of the headset.
- The amplified audio signal of the speaker´s voice will be displayed via oscilloscope.
B. Testing of the capsule via resistor measurement
1. Set the multimeter into resistor measurement mode.
2. Connect the multimeter at the relevant pins of the cable connector, see “Cable connector´s pin alignment”,
page 14 or see “Wiring diagrams”, page 15 et sqq. Result: The multimeter displays 200 ohms ± 10 % for
correct connection of the cable and the capsule. There is no failure or breaking in the cables.
5.2.4 Operational testing of the headset cables
References
•see “Cable connector´s pin alignment”, page 14.
•see “Wiring diagrams”, page 15 et sqq.
A. Conductivity test:
Set the multimeter into the conductivity mode and check each cable from the connector to the system
connector for conductivity.
B. Operational test of the PTT-button:
The contactivity is available when the PTT-button is pressed.
For the following testing procedures disassembling of the headset is necessary.
5.2.5 Audio testing of the headset without cable
A. Testing audio via PCB at the PCB socket P1, see “Printed circuit boards”, page 19.
1. Supply 1 kHz signal at the PCB socket P1.
2. In the headphones, the 1 kHz tone must be audible.
B. Testing of the acoustic transducer.
1. Set the sine wave generator to 100 mVeff ± 5 mV with a signal of 1 kHz to the PCB. Set a signal to TP8 (+)
and TP9 (-), see “Printed circuit boards”, page 19.
2. In the headphones, the 1 kHz tone must be audible.

HME 46-3, HMD 46-3
02/2008 13/25
5.2.6 Testing of the ActiveGard™ of the PCB (not HMD/E 46-31)
1. Connect the sine wave generator with the negative and the positive line at TP3 (+) and TP4 (-), see “Printed
circuit boards”, page 19.
2. Measure the output signal at TP8 (+) and TP9 (-), see “Printed circuit boards”, page 19.
3. The following table show you the input levels of the signal generator and the corresponding
measurement results:
Figure 1
Operational test of the dynamic microphone
Input signal of 1 kHz
at TP3 (+) and TP4 (-)
of the PCB
Output level at TP8 (+) and TP9 (-):
Audible via loudspeaker
Output level at TP8 (+) and TP9 (-):
Damaged loudspeaker or open
cable connection
300 mVeff ±5 mV Output level is reduced about
min. 8 dBV. The PCB with
loudspeaker works correctly.
290 to 310 mVeff
1 Veff ±5 mV 30 to 40 mVeff
Speaker´s voice
Audio amplifier
output
Headphone
connector
input
Microphone
connector
output
Oscilloscope

HME 46-3, HMD 46-3
14/25 02/2008
Figure 2
Microphone test setup according to RTCA/DO-214
Figure 3
Cable connector´s pin alignment
Oscilloscope
Multimeter
Power supply
8-16V DC
Sine wave
generator
Artificial
mouth
Microphone Hi
Microphone Lo
Nearfield sensitivity
25 µF
220 ohms
470 ohms
SPL = 94 dB
6 mm (0.24 inch)
Connector cable -L (also cable HME 46-ATC)
149
8
510
67
2
3
bridge
orange
blue
redbrown
greenn. c.
white
screen
Solder side
Connector system cable
Audio Hi right
Audio Lo right
not connected
Screen
Audio Hi left
Audio Lo left
Microphone Hi
Microphone Lo
Bridge to pin 10
Bridge to pin 9
1
2
3
4
5
6
7
8
9
10
orange
brown
green
yellow
red
blue
screen
Audio Hi left
Audio Hi right
Audio Lo left
Audio Lo right
not connected
Microphone Hi
Microphone Lo
Screen
white
Cable -6
orange
brown
green
yellow
red
blue
screen
Audio Hi left
Audio Hi right
Audio Lo left
Audio Lo right
not connected
Microphone Hi
Microphone Lo
Screen
white

HME 46-3, HMD 46-3
02/2008 15/25
6 Wiring diagrams
6.1 Wiring diagram for cable -E-3PTT-M, -D-3PTT-M
System cable white / orange not connected brown / green not connected yellow screen red blue
white
not connected
brown
green
not connected not connected
screen
E-3PTT-M: red or
D-3PTT-M: orange
blue
white
orange
green
screen
blue
red
brown
soldering side
System cable white / orange
not connected brown / green not connected yellow screen red blue
white
not connected
brown
not connected
green
screen bridge
blue
E-3PTT-M: red or
D-3PTT-M: orange
515760
515761
bridge
Audio Hi Audio Lo Dyn. Mic Hi not connected Pre-polarized Mic Hi PTT PTT / Screen Mic Lo
1 2 3 4 5 6 7 8

HME 46-3, HMD 46-3
16/25 02/2008
6.2 Wiring diagram for cable -PTT-L
System cable white orange brown green yellow screen red blue
white
orange
brown
yellow
green
black
screen
red
blue
brown
screen
white
blue
red
orange
green
bridge
black
yellow
soldering side
Audio Hi left Audio Lo left PTT PTT (bridge to pin 10) Audio Lo right Audio Hi right Microphone Hi Microphone Lo Screen PTT (bridge to pin 4)
1 2 3 4 5 6 7 8 9
10
System cable white orange brown green yellow screen red blue
white
orange
brown
green
yellow
black
screen
red
blue
515760
515761

HME 46-3, HMD 46-3
02/2008 17/25
6.3 Wiring diagram for cable -PTT-6
System cable white orange brown green yellow screen red blue
white
orange
brown
yellow
green
black
screen
red
blue
System cable white orange brown green yellow screen red blue
white
orange
brown
green
yellow
black
screen
red
blue
515760
white
orange
brown
green
yellow
black
red
blue
screen
Audio Hi left Audio Hi right Audio Lo left Audio Lo right PTT PTT Mic Hi Mic Lo Screen
515761

HME 46-3, HMD 46-3
18/25 02/2008
6.4 Wiring diagram for cable -PTT-LA
System cable white orange brown green yellow screen red blue
white
orange
brown
yellow
green
screen
not connected
red
blue
yellow
screen
white
brown
red
blue
soldering side
System cable white orange brown green yellow screen red blue
white
orange
brown
green
yellow
screen
not connected
red
blue
515760
1 2 3 4 5 6 7 8 9
10
Audio Hi right Audio Lo right PTT PTT / screen, bridge to pin 9, resistor 75R between pin 4 and pin 10 Audio Hi left Audio Lo left Mic Hi Mic Lo bridge to pin 4, PTT / screen resistor 75R between pin 4 and pin 10 / screen
515761
10
9

HME 46-3, HMD 46-3
02/2008 19/25
6.5 Printed circuit boards
L
P1
TP1
TP2 TP3
TP4
TP5 TP6 TP7
TP8 TP9
Audio signal
Left
Hi
Right
Hi
Left
Lo
Right
Lo
300 mV/1 kHz 300 mV/1 kHz
510721
(see rear side of the PCB)
L
P1
TP1
TP2 TP3
TP4
TP6 TP5 TP7
TP8 TP9
Audio signal
Left
Hi
Right
Hi
Left
Lo
Right
Lo
300 mV/1 kHz 300 mV/1 kHz
510722
(see rear side of the PCB)
PCB headphone, solder side, PCB-no. 510721 PCB headphone, solder side, PCB-no. 510722
The PCB layout
is simular on
both sides
The PCB layout
is simular on
both sides
The capsule´s impedance has been customized. Therefore the PCB assembling has been changed. For PCB no. 510721 order the •spare part module 527565
(not microphone side) or
•spare part module 525763
(microphone side)
For PCB no. 510722 several spare parts are available.

HME 46-3, HMD 46-3
20/25 02/2008
6.6 Block diagram

HME 46-3, HMD 46-3
02/2008 21/25
7 Exploded views with spare part lists
7.1 Exploded view HME 46-3 / HMD 46-3
120
100
10
threaded pin
20
90
Microphone side
80
70
40
110
50
PCB
60
cable
with screws
transducer
Note: The system module consists of - the resonator (60) - the capsule and - the PCB