ESCO Technologies ETS-Lindgren 3301B User manual

Model 3301B
Active Rod & Field
Antenna
User Manual

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ETS-Lindgren L.P. reserves the right to make changes to any products herein to improve
functioning or design. Although the information in this document has been carefully reviewed and
is believed to be reliable, ETS-Lindgren does not assume any liability arising out of the
application or use of any product or circuit described herein; nor does it convey any license under
its patent rights nor the rights of others. All trademarks are the property of their respective
owners.
©Copyright 2000–2006 by ETS-Lindgren L.P. All Rights Reserved. No part of this
document may be copied by any means without written permission from
ETS-Lindgren L.P.
Trademarks used in this document: The ETS-Lindgren logo is a trademark of ETS-Lindgren L.P.
Revision Record | MANUAL 3301B, Part #399046, Rev. K
Revision Description Date
A – J Initial Release, edits/updates Through September, 2003
K Edited rod capacitance, template/format November, 2006
Internet Address
http://www.ETS-Lindgren.com
USA
1301 Arrow Point Drive
Cedar Park, TX 78613 USA
Tel: [phone]
Fax: [phone]
Email: [email protected]
Finland
Mekaanikontie 1, 27510
Eura, Finland
Tel: [phone]
Fax: [phone]
Email: [email protected]
Japan
4-2-6, Kohinata
Bunkyo-ku, Tokyo 112-0006 Japan
Tel: [phone]
Fax: [phone]
Email: [email protected]
China
B507A Technology Fortune Center
No8 Xue Qing Road
Haidian District
Beijing Postcode: 100083 China
Tel: [phone]
Fax: [phone]
Email: [email protected]

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Table of Contents
Safety Symbol Definitions.................................................................................................................v
General Safety Considerations.........................................................................................................v
1.0 Introduction................................................................................................................................ 7
2.0 Receiving Your Order................................................................................................................ 9
2.1 Unpacking and Acceptance................................................................................................... 9
2.2 Service Procedures................................................................................................................ 9
3.0 Maintenance............................................................................................................................ 11
3.1 Maintenance Recommendations......................................................................................... 11
3.2 Replacement and Optional Parts......................................................................................... 11
4.0 Standard Configuration............................................................................................................ 13
4.1 Options................................................................................................................................. 13
5.0 Specifications .......................................................................................................................... 15
5.1 Operational Specifications................................................................................................... 15
5.1.1 Table of Acceptable Pulse Repetition Rates................................................................. 16
5.2 Electrical Specifications....................................................................................................... 16
5.3 Mechanical Specifications.................................................................................................... 17
6.0 Principles of Operation............................................................................................................ 19
6.1 Description........................................................................................................................... 19
6.2 Front Panel .......................................................................................................................... 19
6.3 Internal Options.................................................................................................................... 20
6.3.1 Factory Settings ............................................................................................................ 21
6.3.2 Proper Selection of Internal Attenuation....................................................................... 22
7.0 Power Circuitry........................................................................................................................ 23
7.1 Voltage-Selectable Battery Charger.................................................................................... 23
7.1.1 Operation....................................................................................................................... 23
7.1.2 Specifications................................................................................................................ 24
7.2 Battery Low Indicator........................................................................................................... 24
7.3 Fuses ................................................................................................................................... 24
8.0 Setup and Use......................................................................................................................... 27
8.1 Setup.................................................................................................................................... 27
8.2 High Sensitivity Readings.................................................................................................... 28

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9.0 Theory of Operation................................................................................................................. 29
9.1 The Rod ............................................................................................................................... 29
9.2 The Pre-Amplifier................................................................................................................. 30
10.0 The Antenna Factor............................................................................................................... 33
11.0 Antenna Impulse Response .................................................................................................. 35
11.1 Impulse Characteristics...................................................................................................... 35
11.2 Pulse Desensitization......................................................................................................... 36
11.3 Pulse Charging .................................................................................................................. 37
12.0 Calibration Procedure............................................................................................................ 39
Appendix A: Warranty Policy for Standard EMCO Brand Products.............................................. 41
Scope and Duration of Warranties............................................................................................. 41
Warranty Exclusions.................................................................................................................. 41
Buyer’s Remedies...................................................................................................................... 42
Appendix B: European Community Declaration of Conformity ..................................................... 45
Appendix C: Data and Illustrations................................................................................................ 47
Periodic Rectangular Pulse Train .............................................................................................. 47
Spectrum of Rectangular Pulse................................................................................................. 47
Altering Pulse Width / Pulse Repetition Rate............................................................................. 48
Active Electric Field Antenna Calibration Fixture....................................................................... 49
Active Rod Antenna Calibration Setup ...................................................................................... 50
Typical Curves—Minimum Discernible Signal at Various Bandwidths...................................... 51
Typical Attenuation Effect for Switches 1 and 2 ........................................................................ 52
Typical Roll Off Curves for Switches 3 and 4 ............................................................................ 53
Typical Roll Off Curves—41” Rod Antenna, 0 dB Attenuation .................................................. 54
Typical Roll Off Curves—41” Rod Antenna, 10 dB Attenuation ................................................ 55
Typical Roll Off Curves—41” Rod Antenna, 30 dB Attenuation ................................................ 56

| v
Safety Symbol Definitions
This product and related documentation must be reviewed for familiarization with
safety markings and instructions prior to operation of the product.
Safety Symbol Definition
!
OR
REFER TO MANUAL—When the product is marked with this symbol
refer to the instruction manual for additional information. If the
instruction manual has been misplaced, go to www.ets-lindgren.com for
downloadable files or contact ETS-Lindgren customer service.
CAUTION—Denotes a hazard. Failure to follow instructions could result
in minor personal injury and/or property damage. Text that follows the
symbol will provide proper procedures.
General Safety Considerations
Safety Symbol Definition
WARRANTY
BEFORE SERVICING: CONTACT ETS-LINDGREN
(+1.512.531.6400)—Servicing or modifying the unit without
ETS-Lindgren authorization may void your warranty. If an attempt to
service the unit must be made, disconnect all electrical power prior to
beginning. Voltages exist at many points within the instrument that
could, if contacted, cause personal injury. Only trained service
personnel should perform adjustments and/or service procedures upon
this instrument. Capacitors inside this instrument may still be charged
even when the instrument is disconnected from the power source.
ONLY QUALIFIED PERSONNEL should operate or service this
equipment.

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Introduction | 7
1.0 Introduction
The ETS-Lindgren Model 3301B is a broadband, high sensitivity electric-field
receiving antenna. The Model 3301B is composed of a monopole rod antenna
with a counterpoise, and a broadband, high impedance pre-amplifier. It is
designed to provide reception of an electric field in a signal band without tuning
or band switching from 30 Hz to 50 MHz. The 3 dB roll off points for the antenna
factor are at 170 Hz and 30 MHz. Between 250 Hz and 20 MHz, the antenna
factor is flat within +/- 1 dB. Despite the roll of the antenna factor, the usable
range is 30 Hz to 50 MHz.
The Model 3301B is designed for maximum sensitivity and dynamic range, and is
capable of sensing fields of 2 dBuV/m at 1 MHz with a 1 kHz bandwidth.
However, it will not saturate below a field strength of 0.7 V/m. As a result, the unit
boasts an extremely wide dynamic range of 115 dB nominal at mid-band. In
addition, at 10 and 30 dB (+/-10%), internal attenuators are provided. With the
attenuators the Model 3301B is usable in fields of up to 22 V/m. Therefore, the
dynamic range of the unit is expanded to 145 dB. A saturation indicator is
provided to alert the user to the need for using the internal attenuators
The Model 3301B is designed to provide the user with an extremely versatile
measurement tool. The flat antenna factor, extreme sensitivity, and ultra-wide
dynamic range make it a state of the art sensing instrument.

8 | Introduction
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Receiving Your Order | 9
2.0 Receiving Your Order
2.1 Unpacking and Acceptance
Step 1. Upon delivery of your order, inspect the shipping container(s) for
evidence of damage. Record any damage on the delivery receipt before signing
it. In case of concealed damage or loss, retain the packing materials for
inspection by the carrier.
Step 2. Remove the product from its shipping container(s). Save the container(s)
and any protective packing materials for future use.
Step 3. Check all materials against the packing list to verify that the equipment
you received matches what was ordered. If you find any discrepancies, note
them and call ETS-Lindgren Customer Service for further instructions.
Make sure you are satisfied with the contents and condition of your order prior to
placing the product into service.
2.2 Service Procedures
To return a system or system component for service:
Step 1. Contact ETS-Lindgren Customer Service to obtain an SRO, Service
Request Order.
Step 2. Briefly describe the problem in writing. Give details regarding the
observed symptom(s) or error codes, and whether the problem is constant or
intermittent in nature. Please include the date(s), the service representative you
spoke with, and the nature of the conversation. Include the serial number of the
item being returned.
Step 3. Package the system or component carefully. If possible, use the original
packing materials to return a system or system component to ETS-Lindgren at
the following address:
ETS-Lindgren
Attn: Service Department
301 Arrow Point Drive
Cedar Park, TX, USA 78613
Phone: [phone]
Customer Service: +1.512.531.6498

10 | Receiving Your Order
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Maintenance | 11
3.0 Maintenance
3.1 Maintenance Recommendations
To ensure reliable and repeatable long-term performance, annual recalibration of
your antenna by an ETS-Lindgren experienced technician is recommended. Our
staff can recalibrate almost any type or brand of antenna. Please call to receive a
Service Order Number prior to sending an antenna for calibration.
For more information about our calibration services, visit our website at
http://www.ETS-Lindgren.com.
3.2 Replacement and Optional Parts
Use the following tables to order replacement or optional parts for the
Model 3301B.
Replacement Part Part Number
Collapsible Rod Element 41” 101263C
24” x 24” Counterpoise 100692
Rod Antenna Pre-Amplifier 100697B
Battery Charger 102615
Model 3301B Active Rod & Field
Antenna User Manual 399046
Table 1: Replacement Parts List
Optional Part Part Number
3301B Calibration Fixture 3301CB
Tripod, Linen Phenolic 3-TR
Remote Status Monitor 3301B-RM
25” Cable RG-223/U with BNC
Connectors C-BNC
Replacement Batteries, 6V (2 required) 400009
Table 2: Optional Parts List

12 | Maintenance
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Standard Configuration | 13
4.0 Standard Configuration
• Adjustable monopole element
• Antenna base with built-in preamplifier and an isolated female BNC connector
• Counterpoise (60 cm)
• Base drilled to accept EMCO or other tripod mounts with standard ¼” x 20 threads
• Batteries and battery charger
• Individually calibrated per ECSM or IEE Std. 291. Actual individual calibration
factors and signed Certificate of Calibration Conformance included with the
manual.
4.1 Options
REMOTE MONITOR
A 10-meter (32.8 ft) fiber optic Remote Monitor Option for remote display of
power-on and saturation indicators.
TRIPODS
ETS-Lindgren offers two nonmetallic, non-reflective tripods for use at both indoor
and outdoor EMC test sites.
• Model 4-TR—Constructed of linen phenolic and delrin, designed with
an adjustable center post for precise height adjustments. Maximum
height for the 4-TR is 2.0 m (80.0 in), and minimum height is 94 cm
(37.0 in). This tripod can support up to an 11.8 kg (26.0 lb) load.
• Model 7-TR—Allows several different configurations, including options
for manual or pneumatic polarization. The 7-TR provides increased
stability for physically large antennas. The unique design allows for
quick assembly, disassembly, and convenient storage. Quick height
adjustment and locking wheels provide ease of use during testing. This
tripod can support a 13.5 kg (30 lb) load. For the 7-TR series,
maximum height is 2.17 m (85.8 in), with a minimum height of .8 m
(31.8 in). The 7-TR is constructed of PVC and fiberglass components.

14 | Standard Configuration
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Specifications | 15
5.0 Specifications
5.1 Operational Specifications
Frequency Range: 30 Hz to 50 MHz (maximum usable
bandwidth)
Low Frequency Roll Off: The low frequency roll off is switch
selectable to be 3 dB down at 22 kHz,
1.9 kHz, or 170 Hz.
High Frequency Roll Off: Antenna factor is 3 dB down at 30 MHz
Antenna Factor:
See data graphs included with manual. The
calibration graphs were taken in the low
gain setting. Unless otherwise noted, the
low frequency roll off is set at the 170 Hz
3 dB roll off point.
Saturation Level:
• 0.7 V/m narrowband without attenuation
and at the low gain setting
• 22 V/m with 30 dB of internal attenuation
selected
• 63 dBuV/m/MHz broadband saturation
level
Minimum Discernible Signal: See data graphs included with manual. For
best sensitivity the unit should be in the low
gain setting with all internal attenuation off.
Dynamic Range:
• 115 dB at mid-band (1 MHz)
• 145 dB with the use of the internal
attenuators

16 | Specifications
Saturation Indicator Impulse Response:
The saturation indicator will properly
indicate saturation for pulsed signals which
fall within the following boundaries:
1. The product of the pulse width to pulse
repetition rate must be greater than .003.
2. The pulse repetition rate must be less
than value listed for the applicable duty
cycle. See the following Table of
Acceptable Pulse Repetition Rates.
5.1.1 Table of Acceptable Pulse Repetition Rates
Duty Cycle Maximum PRF
10 19.7 MHz
20 14.0 MHz
30 9.2 MHz
40 5.6 MHz
50 420.0 kHz
60 130.0 kHz
70 87.0 kHz
80 57.0 kHz
90 30.0 kHz
5.2 Electrical Specifications
Input Impedance:
The input impedance determines the low
frequency roll of point. Depending on the
low frequency roll off selected, the input
impedance is >20 megohms, 1 megohm or
100 kilohm.
Output Impedance: 50 ohm (nominal)
Saturation Impedance:
A red LED on the front panel will illuminate
when the unit begins to saturate or clip. The
saturation indicator will indicate accurately
for any gain and attenuator setting.
Battery Low Indicator:
The power light on the front panel also
serves as a battery low Indicator. If the
green light does not come on when the
power switch is engaged, then the battery
requires recharging. It is recommended that
the Model 3301B be connected to the
battery charger at all times when not in use.

Specifications | 17
Batteries:
The Model 3301B is supplied with two 6V
sealed lead-acid batteries. The batteries will
operate for approximately 10 hours
between charges.
Battery Charger: 115/230 VAC 50/60 Hz switch selectable,
IEC input, two-stage battery charger with
fast and trickle charge modes.
Fuses:
• Type 3AG size .5 Amp, fast acting
• Or, 5 x 20 mm, .5 Amp, fast acting
• Internally mounted
5.3 Mechanical Specifications
Size: 7.38” x 4.62” x 3.5”
Weight: Approximately 7 lbs
Tripod Mounting: A ¼” x 20 hole is provided on the base for
tripod mounting. This is not intended as a
grounding point.
Counterpoise Mounting: Four 6-32 holes are provided in the two
metal mounting bars on the top of the unit.
Antenna Element: The antenna element may be set up to 41”.

18 | Specifications
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Principles of Operation | 19
6.0 Principles of Operation
6.1 Description
The ETS-Lindgren Model 3301B electric field receiving antenna is composed of
three principal sections: a sensing rod, a ground plane or counterpoise, and a
broadband, high input impedance pre-amplifier.
The rod and counterpoise function together as an electrically short antenna over
ground plane. The pre-amplifier provides impedance transformation from the
extremely high impedance at the base of the rod to the 50 ohms required by
most receiving systems, and provides power gain to allow the sensing of very low
level signals.
6.2 Front Panel
On the front panel of the Model 3301B are the following:
• Power switch
• Gain switch
• Saturation indicator
• Battery Low/Power On indicator
• BNC Output port
• Battery Charging port
POWER SWITCH
The power switch is located on the lower right of the front panel. Activating the
power switch will turn on the Battery Low/Power On indicator (green).
BATTERY LOW/POWER ON INDICATOR
The Battery Low/Power On indicator is controlled by a voltage monitor circuit. If
the green indicator does not turn on, or if it turns off during use, the battery
requires charging.
GAIN SWITCH
In the middle left is the Gain switch, which increases the voltage output of the
gain stage in the amplifier by 10 dB. However, best sensitivity is achieved in the
low gain setting. The gain option provides additional output power for test
situations that require additional output.

20 | Principles of Operation
SATURATION INDICATOR
The Saturation indicator is located above the power indicator. Readings should
not be taken when the unit indicates it is in saturation. If this occurs, input to the
unit should be reduced by placing the unit in the low gain mode or by switching in
internal attenuation. Impulsive type signals present a particular problem in that
they may put the unit into a non-linear region without triggering the saturation
circuit. When dealing with impulsive type signals, the 63 dBu V/m/MHz should be
strictly observed. If a signal exceeds this limit, the internal attenuation should be
applied. The limiting factor on handing impulsive signals is the unit output
capability. Therefore, once the internal attenuators are engaged, most higher
impulsive signals may be measured. For example, with the 30 dB attenuator
engaged, a 93 dBuV/m/MHz may be measured.
BATTERY CHARGING PORT
A Battery Charging port is provided for easy recharging of the sealed lead-acid
batteries internal to the unit. To charge the unit, turn off the power switch and
plug in the battery charger. The charging circuit will not charge the batteries
when the unit is on.
6.3 Internal Options
Internal to the unit is a 4-switch bank of slide switches. These switches control
the internal attenuation and the low frequency roll off.
To access the switch bank, hold the unit upside down and remove the bottom
cover. With the unit upside down and the front panel to the left:
• The top switch, closest to the fuse holder, adds 10 dB of internal
attenuation.
• The next switch down adds 30 dB of attenuation.
• The third switch sets the low frequency roll off of 3 dB down at 1.9 kHz.
• The fourth switch sets the low frequency roll off of 3 dB down at
22 kHz.