Telex Echelon 25XT User manual

User Instructions
Echelon 25XT
Noise Reduction Headset
LIT000014 Rev B 6/2009

Uniform Limited Warranty
Bosch branded products are warranted by
Bosch Security Systems, Inc. against
malfunction due to defects in materials and
workmanship for a specified period, as noted
in the individual product line statements
below, beginning with the date of original
purchase by the end-user. if such
malfunction occurs during the specified
period, the product will be repaired with new
or remanufactured equivalent parts and
products or replaced (at our option) without
charge. The product will be returned to the
customer postage prepaid.
Exclusions and Limitations
The limited warranty does not apply to: (a)
exterior finish or appearance; (b) certain
specific items described in the individual
product line statements below; (c)
malfunction resulting from use or operation
of the product other than as specified in the
product data sheet or owner’s manual; (d)
malfunction resulting from misuse or abuse
of the product, including accidents; (e)
defects resulting from excess moisture,
lightening or power surges; or (f)
malfunction occurring at any time after
repairs have been made to the product by
anyone other than a Bosch Service
Department employee or any of its
authorized service representatives. The
warranty is void if the label bearing the
product serial number (if applicable) has
been removed or defaced.
Other Express or Implied Warranties
Excluded
TO THE EXTENT PERMITTED BY
APPLICABLE LAW, THE WARRANTEID
SET FORTH HEREIN ARE IN LIEU OF,
AND EXCLUSIVE OF, ALL OTHER
WARRANTIES, EXPRESS OR IMPLIED.
SPECIFICALLYEXCLUDED, WITHOUT
LIMITATION, ARE THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR
USE OR FOR A PARTICULAR PURPOSE,
AND WARRANTIES ARISING FROM
COURSE OR DEALING OR USAGE OF
TRADE OR ANY OTHER MATTER. IF,
UNDER APPLICABLE LAW, IMPLIED
WARRANTIES MAY NOT BE VALIDLY
EXCLUDED, THE DURATION OF SUCH
IMPLIED WARRANTIES IS LIMITED TO
THE WARRANTY PERIOD.
Limitation of Remedies; Certain
Damages Excluded
REPAIR OR REPLACEMENT OF
DEFECTIVE PRODUCTS ARE THE
SOLE AND EXCLUSIVE REMEDIES
PROVIDED BY BOSCH TO THE
CUSTOMER OR TO ANY OTHER
PERSON AND SHALL CONSTITUTE
FULL SATISFACTION OF ALL CLAIMS,
WHETHER BASED ON CONTRACT,
NEGLIGENCE, STRICT LIABILITY OR
OTHERWISE. BOSCH’S MAXIMUM
LIABILITY SHALL NOT EXCEED THE
ACTUAL PURCHASE PRICE PAID FOR
THE PRODUCT BY THE CUSTOMER.
BOSCH AND ITS SUBSIDIARIES SHALL
NOT BE LIABLE FOR ANY INDIRECT,
INCIDENTAL, PUNITIVE, SPECIAL OR
CONSEQUENTIAL DAMAGES
INCLUDING, WITHOUT LIMITATION,
INJURY TO PERSONS OR PROPERTY
OR LOSS OF USE. SOME STATES AND
COUNTRIES DO NOT ALLOW THE
EXCLUSION OR LIMITATION OF
CERTAIN DAMAGES, SO THE ABOVE
LIMITATION OR EXCLUSION MAY NOT
APPLY TO YOU. IN SUCH STATES AND
COUNTRIES, BOSCH SHALL BE
LIABLE FOR NO MORE THAN THE
DIRECT DAMAGES FOR BODILY
INJURY AND/OR REAL OR PERSONAL
PROPERTY ARISING FROM THE
NEGLIGENCE OF BOSCH.
Other Rights
This warranty gives you specific legal rights,
and you may also have other rights,
depending upon where you live.
Obtaining Warranty Service
To obtain warranty service, a customer must
deliver the product, prepaid, to the
appropriate Bosch Service Department listed
below or any of its authorized service
representatives together with proof of
purchase of the product in the form of a bill
of sale or invoice.

Applicable Law
The validity, performance and construction of
this limited warranty shall be governed by the
laws of the State of Minnesota without
reference to its choice of law principles. The
Minnesota federal courts and/or the state courts
located in Hennepin County, Minnesota, shall
have exclusive personal and subject matter
jurisdiction over, and the parties shall each
submit to the jurisdiction of such courts and to
venue in Minnesota with respect to any dispute
concerning the product or pursuant to this
limited warranty, and all objections to such
jurisdiction or to such venue are hereby waived.
For additional warranty repair or service
information, contact the Bosch Service
Department listed below:
USA, Canada, & Latin America
1720 E, 14th Street
Glencoe, MN 55336
Tel: [phone]
Fax: [phone]
Customer Service
For information or technical assistance, call or
write Bosch at:
Customer Service Department
Bosch Security Systems, Inc.
12000 Portland Ave. So.
Burnsville, MN 55337 U.S.A
[phone]
www.telex.com/aircraft
When returning equipment for repair, please
enclose an explanation of the problem. And, if
the equipment is covered under warranty,
please enclose a copy of your proof of
purchase. The equipment must be accompanied
by documentation stating you name, return
address, and telephone number.
Return equipment for factory repair to:
Customer Service Department
Bosch Security Systems, Inc.
1720 East 14th St.
Glencoe, MN 55336 U.S.A.
[phone]
Warranty Repairs
If in warranty, no charge will be made for the
repairs. Equipment being returned for warranty
repair must be sent prepaid and will be returned
prepaid.
Non-Warranty Repairs
Equipment that is not under warranty must be
sent postage prepaid to Bosch. If requested, an
estimate of repair costs will be issued prior to
service. Once you approve repair, and repair of
equipment is completed, the equipment will be
returned on a collect on delivery basis. Collect
charges may be avoided by sending a signed
check for payment in full along with you signed
estimate approval form (the estimate includes
the shipping charge).
Bosch Warranty Term Lengths
1 Month 3 Months
12
Months
36
Months
60
Months Other
Aviation
Echelon 25XT X
** Warranty subject to change without notice.

Ordering Information
Parts List
Part No. Description Qty
800456022 Replacement Head Pad 1
590637000 Cord Clip 1
800136100 Microphone Element Assembly 1
800456021 Foam Ear Pads (set of 2) 1
800456000 Windscreen 1
CME000009000 Carrying Case 1
550216002 Cell Phone Accessory Cable 1
550216003 Auxillary Device Accessory Cable 1

Table
of
Contents
Headband Size Adjustment ...................................................................4
Headband Pressure Adjustment ............................................................5
Left or Right Side Microphone Placement ............................................6
Connection ............................................................................................7
Stereo Mono Switch ..............................................................................7
Cell Phone/Audio Interface ..................................................................7
Volume Adjustment ...............................................................................8
Microphone Gain Adjustment ...............................................................8
Ear Cushion Replacement ....................................................................9
Mic Element Removal .........................................................................10
Specifications ......................................................................................11

3
FIGURE 1. Echelon 25XT Noise Reduction Headset

4
Headband Size Adjustment
To adjust the headband size, do the following:
1. Move the earcup sliders up or down on the headband.
Size is properly adjusted when the earcups are centered over the ears. It is
important to make the same adjustments to both sides of the headband to
keep the headband and pad properly centered over the head.
FIGURE 2. Headband Size Adjustment

5
Headband Pressure Adjustment
There are three (3) pressure settings for headband comfort. Increasing the pressure
improves the seal between the earcup and the head for greater noise reduction.
To change the pressure setting, do the following:
1. Remove the headset.
2. Fold the earcup inward, as shown in (Figure 3).
3. Rotate the Comfort Cam adjustment knob to the desired setting.
4. Repeat for both earcups.
Both sides of the headband should be set to the same pressure setting to keep
the headband properly centered on the head.
FIGURE 3. Headband Pressure Adjustment
HIGH MEDIUM LOW
Comfort Cam™
ADJUSTMENT KNOB SETTINGS

6
Left or Right Side Microphone Placement
To adjust the microphone to the left or right, do the following:
1. Rotate the boom, as shown inFigure 4.
2. Reshape the boom so the microphone is at the corner of the mouth.
FIGURE 4. Rotating and Reshaping the Boom

7
Connection
Using the headset to the aircraft radio or intercom system as shown in Figure 5.
Stereo Mono Switch
This switch is located on the Y-cord (Figure 5). Set the switch to stereo for aircraft
with a stereo intercom system. Set the switch to mono for monaural intercom systems
or for direct connection to the aircraft radio.
Cell Phone/Audio Interface
The Echelon 25XT includes a unique amplified interface allowing for the connection
of a cellular telephone and an audio input simultaneously. This configuration allows
the user to set up before take-off and eliminates the need to re-configure cords and
equipment when operating the aircraft.
the other unique feature of this interface is the ability to obtain power from the
aircraft’s communications system. By amplifying the inputs, the Echelon 25XT
allows the user to adjust volume level at the headset contributing to the ability to not
need re-configuring while in flight.
FIGURE 5. Echelon 25XT Connectors

8
The Telex Echelon 25XT cell phone/audio interface has been designed to function
with the widest array of cellular telephones and portable audio devices. There are cell
phones and audio devices on the market not designed to industry physical and
electrical standards. These devices are not guaranteed to function properly with the
Echelon 25XT headset.
NOTE: Cell phone usage while in the air or under situations requiring full
attention is not recommended.
For additional information, see the Bosch website
www.telex.com/aircraft
Volume Adjustment
When the microphone is worn on the left side, volume is increased by rotating the top
of the volume controls clockwise. Control operation is reversed when the microphone
is worn on the right side.
Microphone Gain Adjustment
The microphone gain has been factory-adjusted to the nominal level required for
aircraft use and should normally not require readjustment. Readjustment by a
qualified avionics technician is recommended.
To access the gain trimmer, do the following:
1. Insert a small flathead screwdriver through the access hole in the mic
element.
FIGURE 6. Mic Gain Adjustment
MIC GAIN
ADJUSTMENT
ACCESS

9
2. Turn the gain pot clockwise to increase gain.
OR
Turn the gain pot counter-clockwise to decrease gain.
Ear Cushion Replacement
To remove an old ear cushion, do the following:
> Grasp the ear cushion and pull it off the earcup.
To install a new ear cushion, do the following:
1. Starting at the top of the earcup, place the flap on the back of the ear cushion
over the lip along the top of the earcup.
2. Pull the bottom of the ear cushion down over the lip at the bottom of the
earcup.

10
Mic Element Removal
To remove the mic element, do the following:
1. Press and release the catch on the microphone element.
2. Carefully pull out the element.
NOTE: Avoid pulling the microphone wires.
3. Pull the plastic connector housing to unplug the microphone element.
FIGURE 7. Mic Element Removal for Replacement
RELEASE CATCH
MIC ELEMENT

11
Specifications
Receivers
Type: Dynamic
Impedance: accepts 150 Ohm (stereo) 300 Ohm (mono) source
Frequency Response: 350Hz -3.0 kHz ±6dB
Sensitivity: 90 ±5dB SPL for 1mW, 1kHz input
Maximum Power Input: 30mW
Microphone/Amplifier Assembly
Microphone Type: Noise-canceling electret condenser
Output Impedance: 50 Ohm
Frequency Response: 100Hz – 3.5kHz
Sensitivity: -50 ±6dB (ref: 1V/μbar)
Operating Voltage: 8–16Vdc
Cords and Plugs
Cord: 5.5ft (1.7m) “y” cord with stereo/mono selector switch
Receiver Plug: 1/4” stereo phone plug
Microphone Plug: PJ-068 equivalent
2.5mm 3 conductor audio jack for connection to cell phone connection
3.5mm 3 conductior audio jack for connection to auxiliary audio