Pulsar Ametek CH44-VER07 Manuel utilisateur
June 2019
THE BRIGHT STAR IN UTILITY COMMUNICATIONS
ower-Line Carrier
RF Hybrids
Balanced & Skewed
System Manual
CH44–VER07
AMETE Power Instruments
4050 N.W. 121st Avenue
Coral Springs, FL 33065
1–800–785–7274
1–954–344–9822
www.ametekpower.com
June 2019 i
RF Hybrids System Manual
e recommend that you become thoroughly amiliar with the in ormation in this manual be ore
energizing your hybrid unit. Failure to do so may result in injury to personnel or damage to the
equipment, and may a ect the equipment warranty.
AMETEK does not assume liability arising out o the application or use o any product or circuit
described herein. AMETEK reserves the right to make changes to any products herein to
improve reliability, unction or design. Spec i ications and in ormation herein are subject to
change without notice. All possible contingencies which may arise during installation,
operation, or maintenance, and all details and variations o this equipment do not pur port to be
covered by these instructions. I you desire urther in ormation regarding a particular in -
stallation, operation, or maintenance o equipment, please contact your local AMETEK
representative.
Copyright ©
By AMETEK Power Instruments
ALL RIGHTS RESERVED
AMETEK does not convey any license under its patent rights nor the rights o others.
W
IMPORTANT
!
ii
New in this Version of the Hybrids System Manual
The balanced resistive & skewed hybrids have been completely redesigned.
Most of the information contained in this manual is new.
While the concept and functionality is the same, no references to the previous manual are made in this
version of the manual.
Schematics are available upon request.
June 2019 iii
RF Hybrids System Manual
Preface
Scope
This manual describes the operation, specifications, features and typical applications of the Balanced
Hybrid (CH20-BALMN-001) and the Skewed Hybrid (CH20-SKWMN-001). The former sometimes
referred to as B and the latter S. t is intended primarily for use by engineers and technicians involved in
the installation, alignment, operation, and maintenance of the hybrid assemblies.
Equipment Identification
Each hybrid assembly is identified on its nameplate.
roduction Changes
When engineering and production changes are made to one of the hybrid assemblies, a revision notation
is reflected on the part number, related schematic diagram, and associated parts information.
Warranty
Our standard warranty extends for 10 years after shipment. For all repaired units or advance replacements,
the standard warranty is 90 days or the remaining warranty time, whichever is longer. Damage clearly
caused by improper application, repair, or handling of the equipment will void the warranty.
Equipment Return & Repair rocedure
To return equipment for repair or replacement:
1. Call your AMETEK representative at 1–800–785–7274 or e-mail us at
repair[email protected].
2. Request an RMA number for proper authorization and credit.
3. Carefully pack the equipment you are returning.
When returning any equipment, pack it in the original shipping containers, if
possible. Any damage due to improperly packed items will be charged to the cus-
tomer, even when under warranty.
4. Make sure you include your return address and the RMA number on the pack-
age.
5. Ship the package(s) to:
AMETEK Power Instruments
4050 NW 121st Avenue
Coral Sprin s, FL USA 33065
iv
Table of Contents
Chapter No. Pa e No.
1. Ordering nformation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1–1
2. Purpose, Basic Operation & Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2–1
3. Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–1
4. Chassis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4–1
5. Balanced Hybrid / Balance Transformer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5–1
6. Skewed Hybrid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6–1
7. Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7–1
Two Transmitters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7–2
Single FSK Bi-Directional Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7–2
Dual FSK Bi-Directional Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7–2
ON/OFF DCB with FSK Bi-Directional Channel . . . . . . . . . . . . . . . . . . . . . . . . . .7–2
ON/OFF DCB with Dual FSK Bi-Directional Channel . . . . . . . . . . . . . . . . . . . . .7–3
Balance Transformer for Phase-to-Phase Coupling . . . . . . . . . . . . . . . . . . . . . . . . .7–3
Balanced Combiner for Phase-to-Phase Coupling . . . . . . . . . . . . . . . . . . . . . . . . . .7–3
Chapter 1. Ordering Information
Copyright © AMETE Power Instruments
Hybrids Catalog Number Position
Typical Catalog Number HYB1RU FM B2 S1 N
1 – Base Unit1HYB1RU
2 – Chassis Option
Flush ount FM
Projection ount M
3 – Quantity of Balanced Hybrids2
None B0
One B1
Two B2
Three B3
Four B4
4 – Quantity of Skewed Hybrids2
None S0
One S1
Two S2
Three S3
Four S4
5 – Hybrid Options
None N
Balanced Combiner3 B
6 – Other Optional Boards (Quantity)2,4
Blank Indicates No Optional Boards
Balance Transformer BT (1–4)
1234 56
Notes:
1Hybrids are shipped with the following defaults:
• All empty chassis slots already have blank rear cover plates installed automatically & are included in the price of the chassis.
Additional spare blank rear cover plates must be purchased separately.
• Viewed from the front, hybrids are inserted into the chassis from left to right. Balanced hybrids first, followed by any skewed
hybrids, then any optional boards.
• Viewed from the front, optional boards are inserted from right to left.
2Max number of boards in a chassis is 4. So the total number of Balanced (B) + Skewed (S) + Optional Boards can not exceed 4.
For example, HYB1RU-FM-B3-S2-N is an invalid number because it calls for 5 hybrids total (B3, S2).
3Balanced combiner includes interconnecting cables and requires position 3 to be “B4”. This option is for redundancy in phase-to-
phase coupling schemes.
4Position 6 is only used when an optional board is present. Otherwise this catalog number position is blank.
BT1
Page 1–2
RF Hybrids System Manual
Description art Number Equivalent Old Hybrid Type
Balanced Hybrid (Resistive) CH20-BAL N-001 Resistive H1RB or H1RB-40
Skewed Hybrid (Resistive) CH20-SKW N-001 Skewed H1SB or H1SB-R
Balance Transformer CH20-BAL N-002 Resistive H1RB or H1RB-40
1RU Chassis Flush ounting 1088-780 670B695H01 (2RU ounting Plate)
1RU Chassis Projection ounting 1088-824 670B695H01 (2RU ounting Plate)
Table 1–1. Hybrids and Chassis.
Table 1–2. Hybrid Accessories.
Description art Number Main urpose
Projection ounting Brackets 1088-820 Change Flush Chassis to Projection ount
Blank Rear Cover Plate (1 Slot) 1088-834 Cover a Rear Slot after Removing a Hybrid
Coax Cable ale BNC-BNC 1.5 ft. 01W1-COAX2-111 Interconnect Hybrids & Carrier Sets
Coax Cable ale BNC-BNC 5 ft. 01W1-COAX5-111 Interconnect Hybrids & Carrier Sets
Coax Cable ale BNC-BNC 12 ft. 01W1-COAXA-111 Interconnect Hybrids & Carrier Sets
ale BNC to Female UHF Adapter 01NC-A8313-000 ate RG213/RG8 Coax Directly to Output
BNC “T” Connector 01NC-UG274-000 Parallel Receivers onto Hybrid RX Port
Chapter 2. urpose, Basic Operation & Testing
Copyright © AMETE Power Instruments
2.1 Purpose & Bas c Operat on
Hybrids have been used from the beginning with
Power-Line carrier and their basic operation is still
the same as when they originally were developed
many years ago. The hybrid’s primary purpose is to
combine multiple Power-Line carrier (PLC) signals
onto one common coax cable without causing inter-
ference between different transmitters or between
the transmitters and receivers. This is necessary
because two transmitters connected directly
together will load each other down and can cause
signal clipping and intermodulation distortion. Also
a local high powered transmitter can interfere with
a local receiver that is set to receive a weak signal
level from the far-end transmitter. Hybrids solve
these issues by providing isolation between the two
devices being combined while at the same time
allowing them to be combined onto a common coax
without too much signal loss. solation is especially
important when there is close frequency spacing
between carrier sets which is most often the case.
Using hybrids allows the minimum frequency
spacing between carrier sets.
Hybrids are completely bi-directional and have
nothing in them to direct signal flow from the inputs
to the output or vice versa. They act as a combiner
in one direction and a splitter in the opposite
direction. So, going in one direction at the transmit-
ting end of the line, the hybrid combines, but at the
receiving end of the line it splits. The hybrid
labelling of the “inputs” and the “output” is for the
local transmitter’s signal direction.
The application of a “balance transformer” used in
phase-to-phase coupling at the transmitting end, for
example, is a hybrid being used backwards as a
splitter instead of a combiner. n this example, the
output becomes the input and the 2 inputs become
outputs.
PLC hybrids are completely passive devices and
consist only of transformers, resistors, capacitors,
and inductors (depending on the type of hybrid). All
components are rated to handle more power than is
specified on their inputs. This type of design adds to
their long life and robustness.
2.1.1 Multiple Transmitters/Receivers
f multiple transmitters and receivers need to be
combined onto one coax cable, then the hybrids can
be stacked together to achieve this. This is
necessary as each hybrid can only combine 2
devices at one time. So, if 3 devices need to be
combined, then normally 2 hybrids will be required,
if 4 devices, then 3 hybrids and so forth. The
exception is that hybrids are not needed to isolate
high impedance receivers from one another as
receivers can be directly connected together.
2.1.2 Hybrid Types
There are two main types of PLC hybrids: Balanced
(B) and Skewed (S). The balanced hybrid has equal
losses from the inputs to the output. And the skewed
hybrid has unequal (skewed) losses from the inputs
to the output. The skewed hybrid is only used for
combining a transmitter and receiver, never for 2
transmitters. When 2 transmitters are combined, the
balanced hybrid is always used. The skewed hybrid
favors the transmit’s side over the receive side with
less than 0.5 dB loss on the transmit side. (See
Table 2–1). This is done to improve the overall
system signal-to-noise ratio by 3dB by getting 3dB
more transmit power out to the line. At the receive
end of the power line, both the signal and the noise
get equally attenuated so more loss on the receive
side doesn’t affect the S/N ratio. At the transmit
end, only the transmit signal gets attenuated as it
goes out to the power-line so we want to keep atten-
uation low.
Page 2–2
RF Hybrids System Manual
A basic balanced hybrid can be used to illustrate
how it isolates two inputs from one another and
matches impedances as shown in Figure 2–1. The
hybrid acts as a balanced bridge network and when
the output’s load resistance is exactly twice the
center tap resistor value you get infinite loss, theo-
retically, between the 2 inputs. The hybrid, in this
case, is made up of a resistor of 25 ohms, and a
transformer with a center tap on the primary. The
transformer turns ratio is √2/1 with the √2 turns on
the center tapped primary.
Let’s assume the secondary of the transformer is
terminated with a 50 ohm resistor and a voltage (V)
is applied to input port #1. The 50 ohm load will be
reflected in the primary of the transformer as a 25
ohm quantity from point (a) to the center tap (ct).
This is because there is 1 turn on the primary, (a) to
(ct), for every √2 turns on the secondary. The
impedance will be transferred as the square of the
turns ratio, which in this case is 2 to 1. The voltage
V will divide equally between the 25 ohm resistor
and the 25 ohm reflected load into the top half of
the primary. Thus each voltage has a value of V/2,
and in the direction as shown. Since the center
tapped primary of the transformer will act as an
autotransformer, a voltage V/2 will also appear on
the other half of the primary between point (ct) and
(b). The voltage appearing across input port #2, due
to the voltage V at input port #1, is the sum of the
voltages around the loop from (g) to (y). This
resultant voltage is 0 volts. And as shown in Figure
2–1, the hybrid isolates the voltage at one input port
from the other input port. A price must be paid for
this isolation and that is in the loss from the inputs
to the output. One half the power is dissipated for
each input in the center tap balance resistor causing
a 3 dB minimum loss in the power going to the
output from each input.
Figure 2–1.
Resistive Hybrid.
Input
Port
#1
Input
Port
#2
V
(x)
V/2
V/2
V/2
(g)
(y)
(a)
(b)
(ct)
0
50 W
2:1
2
V
25 W
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