Broadcast Electronics Marti Electronics ME-40 User manual

Broadcast Electronics
4100 North 24th Street, Quincy, Illinois 62305 USA • Phone [phone] • Fax [phone] • www.bdcast.com • [email protected]
Marti
Electronics
FM Exciter
MODELS: ME-40
566-017 rev D
April 4, 2011

Marti Electronics
FM Exciter
MODELS: ME-40
©2011 Broadcast Electronics. All rights reserved.
The information in this publication is subject to improvement and change without notice. Although
every effort is made to ensure the accuracy of the information in this manual, Broadcast Electronics
accepts no responsibility for any errors or omissions. Broadcast Electronics reserves the right to
modify and improve the design and specifications of the equipment in this manual without notice.
Any modifications shall not adversely affect performance of the equipment so modified.
Proprietary Notice
This document contains proprietary data of Broadcast Electronics. No part of this publication may be
reproduced, transmitted, transcribed, stored in a retrieval system, translated into any other language
in any form or by any means, electronic or mechanical, including photocopying or recording, for any
purpose, without the express written permission of Broadcast Electronics.
Trademarks
Broadcast Electronics and the BE logo are registered trademarks of Broadcast Electronics.
Marti Electronics and the Marti logo are registered trademarks of Broadcast Electronics.
All other trademarks are property of their respective owners.
No part of this manual may be reproduced, transmitted, transcribed, stored in a retrieval system, or
translated into any language, natural or computer, in any form or by any means, without the prior
written permission of Marti Electronics.
Copyright
Copyright laws protect artwork depicting circuitry in this manual.
Information in this manual is subject to change without notice and does not represent a
commitment on the part of Marti Electronics.
Marti Electronics may make improvements and/or changes in this manual or in the product described
herein at any time.
This product could include technical inaccuracies or typographical errors.

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Marti Electronics
Product Warranty (One-Year Limited)
Broadcast Electronics (BE) hereby warrants all new Marti Electronics branded products, including STL
systems, manufactured by BE, against any defects in material or workmanship at the time of delivery
thereof, or that develop under normal use within a period of one (1) year, from the date of
shipment.
BE reserves the right to repair equipment under warranty with new or refurbished equipment or
parts. BE’s sole responsibility with respect to any equipment or parts not conforming to this warranty
is to replace or repair such equipment upon the return thereof F.O.B. to BE’s factory in Quincy,
Illinois, U.S.A. In the event of replacement pursuant to the foregoing warranty, only the unexpired
portion of the warranty from the time of the original purchase will remain in effect for any such
replacement.
This warranty shall exclude the following products, component parts and/or assemblies:
(a) Transmitter power output tubes shall only carry the original manufacturer’s or
supplier’s standard warranty in effect on their original shipment date.
(b) All computers, computer peripherals, cables, hard disk drives, etc., shall only carry
the manufacturer’s or supplier’s standard warranty in effect on their original
shipment date.
(c) “Components”, defined as separate and individual parts (e.g. transistors, integrated
circuits, capacitors, resistors, inductors, fans, etc), resold by BE from another
manufacturer or supplier, shall only carry a 90 day warranty, effective the date of
shipment. Any such ‘Components’ being returned for warranty claim must be (1)
returned in their original packaging and (2) must be in new, unused condition.
BE is unable to process or resolve component defects or performance concerns on
components that have been soldered, installed, wired or in any way altered from
new their new condition.
(d) “Resale Equipment”, defined as equipment purchased from another manufacturer
or supplier, then resold by BE, shall only carry such manufacturer’s or supplier’s
standard warranty in effect as of the original shipment date. All warranty claims
against any and all ‘resale equipment’ sold by BE must be filed directly with the
original equipment manufacturer. BE is unable to process or resolve equipment
defects or performance concerns on products or services not manufactured by BE.
This warranty shall not extend to claims resulting from any acts of God, terrorism, war, defects or
failures caused by Purchaser or user abuse or misuse, operator error, or unauthorized attempts to
repair or alter the equipment in any way.
Under no circumstances shall BE be responsible for indirect, incidental or consequential damages,
including, but not limited to transportation costs, non-authorized repair or service costs, downtime
costs, costs for substituting equipment or loss of anticipated profits or revenue, incurred by
Purchaser, whether based in contract, tort or for negligence or breach of statutory duty or otherwise.
The terms of the foregoing warranty shall be null and void if the equipment has been altered or
repaired without specific written authorization from BE, or if not installed according to BE’s
instruction manuals, including, but not limited to, the absence of proper grounding, surge (TVSS)
protection on the AC circuit panel or proper lightning protection/grounding on all output circuits, or
if equipment is operated under environmental conditions or circumstances other than those
specifically described in BE’s product literature or instruction manual which accompany the
equipment. The warranty shall be voided if the product or subassembly is equipped with a tamper

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seal and that tamper seal is broken. BE shall not be liable for any expense of any nature whatsoever
incurred by the original user without prior written consent of BE. The warranty provided herein shall
terminate at the end of the period set forth above. This warranty extends only to the original
Purchaser and is not transferable. There are no third party beneficiaries of any of the provisions of
this warranty. If the equipment is described as “used” equipment, it is sold as is and where is and no
warranty applies unless authorized in writing.
EXCEPT AS SET FORTH HEREIN, AS TO TITLE AND AS SPECIFICALLY REQUIRED BY LAW, THERE ARE
NO OTHER WARRANTIES, OR ANY AFFIRMATIONS OF FACT OR PROMISES BY BE, WITH REFERENCE
TO THE EQUIPMENT, OR TO MERCHANTABILITY, FITNESS FOR A PARTICULAR APPLICATION, SIGNAL
COVERAGE, INFRINGEMENT, OR OTHERWISE, WHICH EXTEND BEYOND THE DESCRIPTION OF THE
EQUIPMENT ON THE FACE HEREOF.

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IMPORTANT INFORMATION
EQUIPMENT LOST OR DAMAGED IN TRANSIT -
When delivering the equipment to you, the truck driver or carrier’s agent will present a receipt for
your signature. Do not sign it until you have:
1) Inspected the containers for visible signs of damage and 2) Counted the containers and compared
with the amount shown on the shipping papers. If a shortage or evidence of damage is noted, insist
that notation to that effect be made on the shipping papers before you sign them.
Further, after receiving the equipment, unpack it and inspect thoroughly for concealed damage. If
concealed damage is discovered, immediately notify the carrier, confirming the notification in
writing, and secure an inspection report. This item should be unpacked and inspected for damage
WITHIN 15 DAYS after receipt. Claims for loss or damage will not be honored without proper
notification of inspection by the carrier.
RF PRODUCT TECHNICAL ASSISTANCE, REPAIR SERVICE, PARTS -
Technical assistance is available from Broadcast Electronics by letter, prepaid telephone or E-mail.
Equipment requiring repair or overhaul should be sent by common carrier, prepaid, insured, and well
protected. If proper shipping materials are not available, contact the RF Technical Services
Department for a shipping container. Do not mail the equipment. We can assume no liability for
inbound damage, and necessary repairs become the obligation of the shipper. Prior arrangement is
necessary. Contact the RF Technical Services Department for a Return Authorization.
Emergency and warranty replacement parts may be ordered from the following address. Be sure to
include the equipment model number, serial number, part description, and part number. Non-
emergency replacement parts may be ordered directly from the Broadcast Electronics stock room at
the number shown below.
RF TECHNICAL SERVICES -
Telephone: [phone]
E-Mail: [email protected]
Fax: [phone]
FACILITY CONTACTS -
Broadcast Electronics, - Quincy Facility
4100 N. 24th St. P.O. BOX 3606
Quincy, Illinois 62305
Telephone: [phone]
Fax: [phone]
General E-Mail: [email protected]
Web Site: www.bdcast.com
PARTS -
Telephone: [phone]
E-Mail: [email protected]

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RETURN, REPAIR, AND EXCHANGES -
Do not return any merchandise without our written approval and Return Authorization. We will
provide special shipping instructions and a code number that will assure proper handling and
prompt issuance of credit. Please furnish complete details as to circumstances and reasons when
requesting return of merchandise. All returned merchandise must be sent freight prepaid and
properly insured by the customer.
MODIFICATIONS -
Broadcast Electronics, reserves the right to modify the design and specifications of the equipment in
this manual without notice. Any modifications shall not adversely affect performance of the
equipment so modified.

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SAFETY PRECAUTIONS
PLEASE READ AND OBSERVE ALL SAFETY PRECAUTIONS!!
ALL PERSONS WHO WORK WITH OR ARE EXPOSED TO POWER TUBES, POWER TRANSISTORS, OR
EQUIPMENT WHICH UTILIZES SUCH DEVICES MUST TAKE PRECAUTIONS TO PROTECT THEMSELVES
AGAINST POSSIBLE SERIOUS BODILY INJURY. EXERCISE EXTREME CARE AROUND SUCH PRODUCTS.
UNINFORMED OR CARELESS OPERATION OF THESE DEVICES CAN RESULT IN POOR PERFORMANCE,
DAMAGE TO THE DEVICE OR PROPERTY, SERIOUS BODILY INJURY, AND POSSIBLY DEATH.
DANGEROUS HAZARDS EXIST IN THE OPERATION OF POWER TUBES AND POWER
TRANSISTORS -
The operation of power tubes and power transistors involves one or more of the following hazards,
any one of which, in the absence of safe operating practices and precautions, could result in serious
harm to personnel.
A. HIGH VOLTAGE - Normal operating voltages can be deadly. Additional information follows.
B. RF RADIATION - Exposure to RF radiation may cause serious bodily injury possibly resulting
in Blindness or death. Cardiac pacemakers may be affected. Additional information
follows.
C. HOT SURFACES - Surfaces of air-cooled radiators and other parts of tubes can reach
temperatures of several hundred degrees centigrade and cause serious burns if touched.
Additional information follows.
D. RF BURNS - Circuit boards with RF power transistors contain high RF potentials. Do not
operate an RF power module with the cover removed.

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HIGH VOLTAGE –
Many power circuits operate at voltages high enough to kill through electrocution. Personnel should
always break the primary AC Power when accessing the inside of the transmitter.
RADIO FREQUENCY RADIATION -
Exposure of personnel to RF radiation should be minimized, personnel should not be permitted in the
vicinity of open energized RF generating circuits, or RF transmission systems (waveguides, cables,
connectors, etc.), or energized antennas. It is generally accepted that exposure to “high levels” of
radiation can result in severe bodily injury including blindness. Cardiac pacemakers may be affected.
The effect of prolonged exposure to “low level” RF radiation continues to be a subject of
investigation and controversy. It is generally agreed that prolonged exposure of personnel to RF
radiation should be limited to an absolute minimum. It is also generally agreed that exposure should
be reduced in working areas where personnel heat load is above normal. A 10 mW/cm2per one
tenth hour average level has been adopted by several U.S. Government agencies including the
Occupational Safety and Health Administration (OSHA) as the standard protection guide for
employee work environments. An even stricter standard is recommended by the American National
Standards Institute which recommends a 1.0 mW/cm2 per one tenth hour average level exposure
between 30 Hz and 300 MHz as the standard employee protection guide (ANSI C95.1-1982).
RF energy must be contained properly by shielding and transmission lines. All input and output RF
connections, such as cables, flanges and gaskets must be RF leak proof. Never operate a power tube
without a properly matched RF energy absorbing load attached. Never look into or expose any part
of the body to an antenna or open RF generating tube or circuit or RF transmission system while
energized. Monitor the tube and RF system for RF radiation leakage at regular intervals and after
servicing.
HOT SURFACES –
The power components in the transmitter are cooled by forced-air and natural convection. When
handling any components of the transmitter after it has been in operation, caution must always be
taken to ensure that the component is cool enough to handle without injury.

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Table of Contents

1INTRODUCTION............................................................................................................... 1
1.1EQUIPMENT DESCRIPTION..............................................................................................1
1.2PHYSICAL DESCRIPTION. ................................................................................................1
1.3ELECTRICAL DESCRIPTION...............................................................................................1
1.4EQUIPMENT SPECIFICATIONS. ........................................................................................2
2INSTALLATION................................................................................................................. 3
2.1 UNPACKING. .................................................................................................................3
2.2 INSTALLATION. .............................................................................................................3
2.3PRELIMINARY INSTALLATION. .......................................................................................4
2.4INSTALLATION ADJUSTMENTS........................................................................................7
3Operation ..................................................................................................................... 10
3.1CONTROLS AND INDICATORS. ....................................................................................10
3.2 OPERATION. ................................................................................................................10
4OVERALL THEORY OF OPERATION ................................................................................ 14
4.1POWER SUPPLY/CONTROL CIRCUITS. ...........................................................................14
4.2RFI FILTER NETWORK. .................................................................................................14
4.3METERING CIRCUIT. .....................................................................................................15
4.4AFC/PLL CIRCUIT. ........................................................................................................15
4.5MODULATED OSCILLATOR CIRCUIT. ............................................................................15
4.6RF AMPLIFIER ASSEMBLY. ...........................................................................................15
5MAINTENANCE ............................................................................................................. 16
5.1SAFETY CONSIDERATIONS .........................................................................................16
5.2FIRST LEVEL MAINTENANCE ......................................................................................16
5.3SECOND LEVEL MAINTENANCE .................................................................................16
5.4ADJUSTMENTS.............................................................................................................17
5.5TROUBLESHOOTING.....................................................................................................17
5.6INTEGRATED CIRCUITS .................................................................................................20
5.7EXCITER PREPARATION FOR SHIPMENT. ....................................................................20
5.8EXCITER FREQUENCY CHANGE. ...................................................................................20
5.9POWER SUPPLY/CONTROL CIRCUIT BOARD ...................................................................21
5.10MODULATED OSCILLATOR ASSEMBLY ..........................................................................35
5.11AFC/PLL .......................................................................................................................39
5.12RF AMPLIFIER...............................................................................................................53
6BILL OF MATERIAL ........................................................................................................ 65
7SCHEMATICS................................................................................................................. 81

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1INTRODUCTION
Information presented by this section provides a general description of the ME-40 FM Exciter features and lists
equipment specifications.
1.1 EQUIPMENT DESCRIPTION.
The ME-40 exciter is available in several configurations. Refer to the following list for various exciter models,
spare parts kits, and options available.
•979-1053 100% Spare Semiconductor Kit
•979-1052 Recommended Spare Semiconductor Kit
•979-1051 Spare Parts Kit
1.2 PHYSICAL DESCRIPTION.
The ME-40 chassis is equipped with slide rails to allow easy access to all assemblies when the unit is extended
from the rack. Removal and installation of assemblies within the exciter is facilitated by the semi-modular
mechanical construction. Each assembly is firmly mounted to the main chassis and electrically connected to the
main wiring harness with plugs and jacks. Input and output connections are routed to a rear-panel terminal strip
and BNC connectors.
1.3 ELECTRICAL DESCRIPTION.
The Marti Electronics ME-40 is a solid-state wideband FM exciter providing a continuously variable RF output
from 3 to 40 watts into a 50 Ohm load at any frequency within the 87.5 to 108 MHz FM broadcast band in 10
kHz increments. The ME-40 accepts multiple wideband composite inputs from a stereo generator or SCA
generator in addition to a 600 Ohm balanced monaural input. Typical performance exhibits extremely low
distortion with THD and IMD less than 0.05% and a typical signal-to-noise ratio of 80 dB. A tapped dual primary
power transformer and a voltage selector allows operation from a wide range of ac input potentials.
1.3.1 METERING
Exciter operating parameters are monitored by a front-panel Test Meter and peak-hold modulation LED display.
Test Meter functions are Forward Power, Reverse Power, P.A. Current, P.A. Voltage, +13 volt Supply, and AFC
Level. Modulation levels of 100% and greater are displayed for one second.
1.3.2 STATUS DISPLAYS
The ME-40 is designed with front-panel LEDs to indicate the status of Overtemperature, VSWR (greater than
1.5:1) and AFC Lock.
1.3.3 AUTOMATIC FREQUENCY CONTROL
A temperature compensated reference oscillator and a dual-speed phase-locked-loop controlling the carrier
frequency locks the frequency of the modulated oscillator to the precision reference frequency oscillator allowing
prompt on-frequency operation of the exciter from a cold start. The ME-40 will achieve frequency lock from a
cold start in less than five seconds.
1.3.4 CONTROL CIRCUIT
The control circuitry provides automatic control of RF output to maintain a preset power output. In addition, the
control circuitry eliminates adjustments after the initial setup, protects the RF output circuitry from excessive

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temperatures, high VSWR conditions, over-voltage conditions, and short circuit conditions.
1.3.5 RF AMPLIFIER
The RF amplifier is a broadband 3 to 40 watt amplifier covering the entire commercial FM broadcast band.
Tuning of the amplifier is not required.
1.4 EQUIPMENT SPECIFICATIONS.
Refer to Table 1-1 for electrical and performance specifications and Table 1-2 for physical and environmental
specifications of the ME-40 FM Exciter.
TABLE 1-1. ME-40 EXCITER SPECIFICATIONS
GENERAL SPECIFICATIONS
PARAMETER SPECIFICATIONS
Frequency Range 87.5 to 108 MHz, tuned to specific operating frequency.
Exciter programmable in 10 KHz steps.
RF Output Impedance 50 Ohms
Power Output 3 Watts to 40 Watts, Continuously Variable (Type BNC
female connector) Open and Short Circuit Protected.
VSWR Rated power 40 watts into 1.5:1 maximum, without
output matching (capable of operating into higher VSWR
with automatic power reduction). Open and short circuit
protected at all phase angles with automatic power
control.
R.F. Harmonics Meets or exceeds all FCC, DOC, and CCIR standards.
Frequency Stabilit
y
+500 Hz, +32˚F to + 122˚F (0˚C to +50˚C).
Modulation Type Direct FM at the Carrier Frequency.
Modulation Capabilit
y
+300 kHz
Modulation Indication Peak Reading, Color Coded, LED Display with Baseband
Over-Modulation Peak Hold indicator. One (1) second
hold time for peaks above 100% modulation.
Asynchronous AM S/N Ratio 60 dB Below 40 watt Reference Carrier with 100%
Amplitude Modulation @ 400 Hz and 75 Microsecond
De-emphasis (No FM Modulation Present).
Synchronous AM S/N Ratio 50 dB Below 40 watt Reference Carrier with 100%
Amplitude Modulation @ 1 kHz (FM Modulation: +75
kHz @ 400 Hz @ 25 watts output power).
Test Meter 6 function analog meter with selector switch.
Test Points Internal test points available.
Audio/Control Connections 14 Terminal Barrier Strip, 5 BNC Connectors.
AC Input Power Requirements 97 to 133V AC or 194 to 266V AC, 50/60 Hz, 210W
Maximum.
MONAURAL OPERATION
PARAMETER SPECIFICATIONS
Audio Input Impedance 600 ohms balanced, resistive, adaptable to other
impedances, 60 dB common mode suppression.
Audio Input Level +10 dBm nominal for +75 KHz deviation @ 400 Hz;
adjustable to other levels.
Audio Frequency Response 0.5 dB, 30 Hz to 15 KHZ, selectable flat, 50, 75
microsecond pre-emphasis.
THD + Noise 0.05% or less at 400 Hz.
SMPTE IM Distortion 0.05% or less, 60 Hz/7 KHz, 4:1 ratio.

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CCIR IM Distortion 0.05% or less, 15 KHz/14 KHz, 1:1 ratio.
FM S/N Ratio 80 dB below +75 KHz deviation @ 400 Hz measured in a
20 Hz to 30 KHz bandwidth with 75 us de-emphasis.
WIDEBAND COMPOSITE OPERATION
PARAMETER SPECIFICATIONS
Inputs 2 total, (1) unbalanced and (1) balanced.
Input Impedance 10 K ohm or 50 ohm, nominal, resistive selectable.
Input Level 3.5 V p-p nominal, for +75 KHz deviation.
FM S/N Ratio 80 dB below +75 KHz deviation @ 400 Hz. Measured in
a 20 Hz to 200 KHz bandwidth with 75 us de-emphasis.
Harmonic Distortion + Noise 0.05% or less @ 400 Hz.
SMPTE IM Distortion 0.05% or less, 60 Hz/7 KHz, 1:1 ratio.
CCIF IM Distortion 0.05% or less, 15 KHz/14 KHz, 1:1 ration.
Amplitude Response +0.1 dB, 30 Hz to 53 KHz.
Phase Response +0.25 degrees from linear phase, 30 Hz to 53 KHz.
TABLE 1-2. PHYSICAL AND ENVIRONMENTAL SPECIFICATIONS
PARAMETER SPECIFICATION
PHYSICAL
Weight:
Packed
Unpacked
Dimensions:
Height
Width
Depth
46 Pounds (20.8 kg).
38 Pounds (17.2 kg).
5.25 Inches (13.3 cm).
17.70 Inches (44.9 cm).
19.00 Inches (48.3 cm).
ENVIRONMENTAL
Ambient Operation Temperature
Humidity
Altitude
0˚C to +50˚C
95% Maximum, Non-Condensing.
7500 ft. @ 50 Hz (2286M); 10,000 ft @ 60 Hz
(3048M)
2INSTALLATION
This section contains information required for installation and preliminary checkout of the
Marti Electronics
ME-40 FM Exciter.
2.1 UNPACKING.
The equipment becomes the property of the customer when the equipment is delivered to the carrier.
Carefully unpack the exciter. Perform a visual inspection to determine that no apparent damage has been
incurred during shipment. All shipping materials should be retained until it is determined that the unit has
not been damaged. Claims for damaged equipment must be promptly filed with the carrier or the carrier
may not accept the
claim.
The contents of the shipment should be as indicated on the packing list. If the contents are incomplete,
or if the unit is damaged electrically or mechanically, notify both the carrier and Marti
Electronics.
2.2 INSTALLATION.
Each exciter is assembled, operated, tested, and inspected at the factory prior to shipment and is ready for

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installation when received. Prior to installation, this publication should be studied to obtain a thorough
understanding of the operation, circuitry, nomenclature, and installation requirements. Installation is
accomplished as follows: 1) Preliminary Installation, 2)
Wiring, and 3) Exciter Checkout.
2.3 PRELIMINARY INSTALLATION.
Table 1-2 (SECTION I, GENERAL INFORMATION) provides physical and environmental conditions which
should be considered prior to ME-40 installation.
The ME-40 exciter may be installed in any convenient location in a 19 inch (48.3 c m) rack within reach
of signal and power cables. The exciter should not be installed directly above or below heat generating
equipment, otherwise no special requirements need be observed.
WARNING
DISCONNECT ALL RACK POWER BEFORE ATTEMPTING
EXCITER I NSTALL A TION.
1. Place the exciter on a work surface.
2. Remove any packing material from the outside of the exciter.
3. Refer to Figure 2-1 and ensure the appropriate primary AC line voltage is visible on the AC LINE
VOLTAGE SELECTOR circuit board (100V, 115/120V, 220V, or 230/240V).
4. If an alternate AC line voltage is required, remove the AC LINE VOLTAGE SELECTOR circuit board with a
small pair of needle nose pliers. Re-insert the circuit board so that the correct AC line voltage is visible
when the circuit board is inserted into the receptacle.
5. Ensure the line fuse and spare fuse are both slow-blow types and rated at 3.0 amperes for the 100 to
120 volt range or 1.5 ampere for the 220 to 240 volt range.
6. The following procedure is for a field rack mount installation.
a) Locate the slide rail mounting brackets and the movable portion of each slide rail in the accessory
kit.
b) Refer to Figure 7-6, SECTION VII, DRAWINGS and secure the slide rail mounting brackets to the
respective side of the rack cabinet with the hardware supplied.
CAUTION
THE SLIDE RAILS MUST BE PARALLEL TO EACH OTHER AND LEVEL BEFORE DRILLING ANY HOLES TO MOUNT THE
REAR OF THE SLIDE RAILS.
CAUTION
c) Secure the movable portion of the slide rail to the mounting brackets with the hardware supplied.

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d) After the slide rails are mounted, lift the exciter onto the rails over the slide stops and push the
exciter into the rack.
7. Pull the exciter forward until the slide rail stops are encountered.
8. Loosen the eight turn-lock fasteners on the top of the exciter and remove the top cover.
9. Remove any packing material from the inside of the exciter.
10. Refer to Figure 2-2 and ensure AUTO-PWR-MAN switch S1 and NORM-EXT switch S2 on the power
supply/control circuit board assembly are operated to AUTO and to NORM respectively.
11. POS-MUTE-NEG switch S3 on the power supply/control circuit board is provided to select the RF mute
input logic polarity (refer to Figure 2-2). S3 must be in the POS position when the ME-40 is operated
with a Broadcast Electronics transmitter or as a stand-alone unit. Switch S3 is factory operated to the
POS position prior to shipping.
12. Refer to the final test data sheets shipped with the exciter and ensure the SYNTHESIZER FREQUENCY
SELECTION switches on the AFC/PLL assembly are correctly positioned.
13. Refer to Figure 2-2 and remove the two shipping screws which secure the modulated oscillator
assembly to operate the shock mounts.
14. Replace the top cover on the exciter and secure the eight turn-lock fasteners on the top of the cover.
Figure 2-2

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2.4 INSTALLATION ADJUSTMENTS
2.4.1 GAIN SELECTION
The gain of the balanced monophonic audio processing circuit on the AFC/PLL circuit board is selectable for
input levels ranging from 0.0 dB to +10 dB. The ME-40 is shipped from the factory for an input level of +10 dB.
If an alternate level is required, refer to Figure 2-3 and connect the appropriate resistor between terminals E1
and E2 as determined by the following information.
INPUT
LEVEL RESISTOR VALUE
+10dBm OMIT
+8 dBm 39K Ohm
+4dBm 10k Ohm
0.0 dBm 4.7k Ohm
Figure 2-3
WARNING
DISCONNECT ALL SYSTEM POWER BEFORE PROCEEDING.
WARNING
2.4.2 WIRING
Refer to Figure 2-1 and connect a coaxial cable (located in the accessory kit) between the RF OUTPUT connector
on the exciter rear-panel and a 50 Ohm RF load capable of dissipating the output of the exciter. Refer to Figure
2-1 and connect the external signal inputs and remote control wiring as required. A second coaxial cable is
provided to connect an SCA or composite input to the exciter.
WARNING
THE EXCITER CASE MUST BE CONNECTED TO EARTH GROUND .
WARNING
2.4.3 GROUND
Ensure a ground wire is connected from terminal 4 of the exciter rear-panel terminal board to earth ground
.
2.4.4 EXCITER
CHECKOUT.
1. Before proceeding, check the following:
A Ensure all connections at terminal strips are secure.
B. Ensure primary power is properly programmed.
C. Ensure the chassis ground connection is
secure.

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D. Ensure all signal inputs are secure.
E. Ensure the RF output is properly
connected.
F. Ensure all external cabling is properly dressed and
secured.
CAUTION
THE PRIMARY AC POWER USED MUST BE THE
SAME AS DISPLAYED ON THE AC LINE VOLTAGE
SELECTOR CIRCUIT BOARD.
CAUTION
2. Connect the exciter to an appropriate power source with the power cord provided. The
following
events will occur.
A. The fan will begin to
operate.
B. Select +13 V
Supply on the TEST METER switch. The meter should indicate approximately 13
on the 25 volt
scale.
C. Set TEST
METER to Forward Power position.
D. The
TEST METER will indicate approximately 5 watts.
3. Rotate
TEST METER switch to AFC Level position.
The TEST
METER will indicate a level within the range of 2 to 9 dependent upon carrier frequency.
Refer to the final test data sheets for the correct
indication.
4. Rotate the
TEST METER switch in Reverse Power position.
The meter should read near zero watts assuming a perfect 50 ohm resistive load is connected
to
the exciter output BNC connector
5. Rotate the
TEST METER switch to P.A. Current position.
The
TEST METER will indicate approximately 1 A. (assuming an RF output power of 5 watts. )
6. Rotate the TEST
METER switch to Forward Power position.
A. Extend the exciter forward on the slide rails to expose the R.F. POWER OUTPUT
ADJ. control
access hole in the left side of the top
cover.
B. Using an insulated adjustment tool, adjust the exciter output power to the level required by
the
transmitter.
WARNING
DISCONNECT EXCITER PRIMARY POWER BEFORE PROCEEDING.
WARNING
7. Disconnect AC primary power from the
exciter.
8.
Disconnect the RF load and connect the exciter output to the transmitter RF input connector.
2.4.5 CONNECTION OF COMPOSITE STEREO SIGNAL
SOURCES.
Two composite input jacks (BAL, UNBAL) are provided on the rear-panel of the ME-40
for

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connection to a composite stereo source such as a stereo generator or composite STL receiver
(refer to Figure 2-1).
Both the UNBAL and BAL inputs require a level of 3.5V p-p (1.24 VRMS) to modulate the carrier at
±75 kHz. These jacks may be used entirely independent of each other and will accept frequencies of
less than 1 Hz to 100 kHz. If these inputs are used, the output level on the composite source must be
adjusted to obtain 100% peak modulation as indicated by the ME-40 modulation display (LED
bargraph).
The BAL input is AC coupled at the input and provided with common mode rejection
circuitry.
Therefore, the BAL input must be used if ground loops and hum are present between the
exciter
and composite source.
2.4.6
CONNECTION OF SCA SIGNAL SOURCES.
SCA unbalanced input receptacles SUB-1, SUB-2, and SUB-3 are provided on the rear-panel of the
ME-40. Each input is AC coupled and accepts frequencies from 40kHz to 100kHz. An input of 3.5V P-
P (1.24 VRMS) will modulate the FM carrier 10% at ±7.5 kHz.
When using an SCA input, the output level of the SCA Generator must be adjusted to obtain the
desired peak modulation as indicated by an FM modulation monitor. Each input is also compatible
with any SCA generator using a de coupled input for the transmission of data.
2.4.7 LOW-PASS FILTER
INSTALLATION.
The ME-40 exciter can be equipped with an optional low-pass filter to allow the unit to operate as a
low power transmitter. The optional low-pass filter is installed as follows.
Remove the exciter top-panel. Refer to Figure 2-4 and secure the low-pass filter to the inside rear-
panel with the hardware supplied.
Remove the coaxial cable from the RF OUTPUT receptacle and connect to filter input receptacle J 1.
Connect the short coaxial cable (supplied) between filter receptacle J2 and the RF OUTPUT receptacle.
When installation is complete, replace the exciter top-panel.

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Figure 2-4
3Operation
This section identifies all controls and indicators associated with the ME-40
FM Exciter and provides
standard operating
procedures
3.1 CONTROLS AND INDICATORS.
Refer to Figure 3-1 for the location of all controls and indicators associated with normal operation of the
ME-40 Exciter. The function of each control or indicator is described in Table 3-1.
3.2 OPERATION.
NOTE
THE FOLLOWING PROCEDURE ASSUMES THAT THE EXCITER IS COMPLETELY
INSTALLED AND IS FREE OF ANY
DISCREPANCIES
NOTE