Products
Comparison Noise Emiiter
Now available in two versions the traditional CNE III
and now, the new low cost CNE V
The Comparison Noise Emitter (CNE) has for a long time been
regarded as the standard for checking the consistency of emissions measurements.
It has an inherent stability that enables long term comparisons to be made.
Used by UKAS (NAMAS) for the last
7 years to compare accredited test sites to the National Standard Open Area Test
Site it has been significant in identifying Site and Antenna problems.
Now a lower cost version is available to cover the radiated frequency range of 30 to 1000 MHz operated by a single PP3 Battery it is convenient enough to use regularly, giving on going confidence in the integrity of measurement.
CNE III - The internationally accepted reference source.
The University of York developed the Comparison Noise Emitter, CNEIII, as a research tool for the evaluation of screened room resonances. It has been used as a reference source for intersite comparison in a number of national and international studies including one by UKAS.
Radiated emissions
The CNE is a broadband noise source with a usable output power from 9kHz to 2GHz. Three monopole antennas are available which may be attached to the BNC connector on the top of the unit enabling it to act as a radiating field source.
The CNE can be used as a source for carrying out checks on open area test sites (OATS) and anechoic chambers. The broadband nature of the output enables the observation of details which would be missed with a comb generator. The power output of the unit also avoids the overloads possible with impulsive noise sources which may cause damage to the sensitive input circuits of receiving equipment.
The unit is battery powered so that it can be operated as a ‘small’ source without the effect of cables which would modify the fields generated. Alternatively cables can be connected to the output or the earth stud on one side of the unit, to investigate the effect of cables and cable positioning on measurements. The CNE is housed in a plated metal box so that it can be mounted in direct contact with a metal ground plane if desired.
The batteries are easily removed and replaced to minimise
the potential down time.
Conducted emissions
An adaptor is available which provides a
capacitive link from the output of the CNE to a standard IEC 320 mains power
connector. This allows checks and investigations on conducted measurements to be
made (e.g. LISN, absorbing clamp).
Operation
The microprocessor control allows the operating time of
the unit to be adjusted from a minimum period of 15 minutes to continuous
operation. The unit will turn off automatically if the batteries are low.
Applications include:
Comparison between different measurement
environments such as OATS or Anechoic Chambers
Radiated and conducted measurement
systems as a reference source for:
Daily pre-test checks as required by the
accreditation authorities
Long term performance monitoring
Cable position investigation
Characterising filter performance
Measuring cable losses
The Comparison Noise Emitter
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Technical
details |
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Output |
50
Ohm nominal 9kHz-2GHz |
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Enclosure |
Chrome
plated steel box |
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Dimensions |
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length |
188mm
(206mm including battery covers |
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width |
120mm |
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height |
62mm
(80mm including BNC connector) |
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weight |
1.3kg |
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Timer
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15
min to 135 min in 15 min steps or continuous operation |
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Power
source |
4
C cells (1.2 - 1.5V nominal per cell) |
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Antennas |
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100mm
top loaded monopole |
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length |
100mm |
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disk
diameter |
100mm |
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recommended
freq. range |
30MHz-1GHz |
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115mm
top loaded monopole |
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length |
268mm |
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disk
diameter |
115mm |
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recommended
freq. range |
30MHz-100MHz |
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1-2GHz
monopole |
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length |
37mm |
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counterpoise
diameter |
100mm |
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recommended
freq. range |
1GHz-2GHz |
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Note
that at higher frequencies than those recommended, care should be
exercised owing to antenna resonances. |
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LISN adaptor |
(240V
line voltage maximum) |
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Capacitively
couples the CNE output to the neutral of an IEC 320 mains plug. |
CNE - Typical power output into 50 Ohms
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CNE - Typical field strengths |
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A - at 10m on an OATS. |
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B - in an anechoic chamber at
3m. |
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Measurement taken with the 100mm
top loaded monopole. |
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Vertical polarisation with
bandwidth of 120kHz. |
CNE III Ordering Information
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Type
Code |
Description |
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CNE
III |
9kHz
to 2GHz Comparison noise emitter |
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TLM01 |
100mm
top-loaded monopole (30MHz-1GHz) |
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TLM02 |
115mm
top-loaded monopole (30MHz-100MHz) |
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MON01 |
Monopole
Antenna (1-2GHz) |
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LSA01 |
LISN
adaptor |
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BCH01 |
C
cell Battery Charger (UK mains plug - 230V) |
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CAS01 |
CNE
III Carrying Case |
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Order
Code |
Description |
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CNEP01 |
CNE
III, TLM01, LSA01, manual & CAL01 |
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Order
Code |
Description |
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CAL01 |
Standard
Calibration (into 50 Ohms) |
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CAL02 |
Calibration
on YES OATS (horizontal & vertical polarisation @ either 10m or 3m) |
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The CNE V is a broadband noise
source, with an output frequency range of 30MHz-1000MHz. It offers a lower cost
option for users of pre-compliance test equipment and facilities.
The low cost Comparison Noise
Emitter - CNE V
Description
The CNE V is a broadband noise source with a useable
output power from 30MHz to 1GHz. A monopole antenna is available which may be
attached to the BNC connector on the top of the unit enabling it to act as a
radiating field source. The CNE can be used as a source for carrying out checks
on open area test sites (OATS) and anechoic chambers. The broadband nature of
the output enables the observation of details that would be missed with a comb
generator.
The power output of the unit also avoids the over-loads
possible with impulsive noise sources which may cause damage to the sensitive
input circuits of receiving equipment. The unit is battery powered so that it
can be operated as a 'small' source without the effect of cables which would
modify the fields generated. An LED indicates when the battery power is low. The
battery is easily removed and replaced to minimise the potential downtime. The
CNE is housed in a plated metal box and can be orientated to give vertical or
horizontal polarisation. The small size and light weight make it ideal for spot
checks and portability.
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Technical
details |
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Frequency
range |
30MHz-1GHz
(useable down to 150kHz) |
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Output |
50
Ohm nominal |
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Enclosure |
Chrome
plated steel box |
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Dimensions |
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length |
120mm |
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width |
120mm |
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height |
41mm
(60mm including BNC connector) |
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weight |
525g |
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Power
source |
PP3
9V battery |
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Antenna TLM01
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100mm
top loaded monopole |
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Length |
100mm |
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Disk
diameter |
100mm |
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Frequency
range |
30MHz-1GHz |
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CNE - Typical field strengths |
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A - at 10m on an OATS. |
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B - in an anechoic chamber at
3m. |
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Measurement taken with the 100mm
top loaded monopole. |
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Vertical polarisation with bandwidth of 120kHz |
CNE V Ordering Information
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Type
Code |
Description |
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CNE
V |
30MHz
to 1GHz Comparison Noise Emitter |
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TLM01 |
100mm
top-loaded monopole (30MHz-1GHz) |
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BCH02 |
PP3
Battery Charger (UK Mains plug - 230V) |
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Order
Code |
Description |
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CNEP02 |
CNE
V, TLM01, Battery Charger, manual & CAL03 |
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CNEP03 |
CNE
V, TLM01, manual and CAL03 |
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Order
Code |
Description |
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CAL03 |
Standard
Calibration: Direct o/p into 50 OhmsRadiated emissions in anechoic
chamber @ 3m All measurements made on a Spectrum Analyser |
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CAL04 |
Calibration
on YES OATS: Direct o/p into 50 Ohms Radiated emissions @ either 3m or
10m Measurements made on a Spectrum Analyser |
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CAL05 |
As
CAL04 but with measurements made on a receiver |
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