The RFL 9780/9785 Auxiliary Hybrid Chassis is a 19-inch rack-mountable unit designed to accommodate X-Hybrid or Skewed Hybrid modules for RFL Powerline Carrier systems. It occupies less than one rack unit of vertical space (1.718 inches, or 4.4 cm). Each chassis can hold up to three Hybrid modules and three Hybrid I/O modules. The Hybrid modules are mounted at the front, while the Hybrid I/O modules are at the rear. The chassis allows for a mix of X-Hybrid and Skewed Hybrid modules.
X-Hybrid Module
Function Description:
The X-Hybrid Module is a transformer-type hybrid primarily used to combine the outputs of two transmitters. It provides essential impedance matching and signal separation, preventing mutual loading between the two transmitters. It can also connect a transmitter and a receiver, or two receivers, to a single line tuning unit. Signals can be accepted from an amplifier with a source impedance of 50 Ohms and up to 10 Watts of output power.
The transmitted signals pass through a transformer hybrid formed by transformers L1 and L2. Each transformer has two secondaries interconnected such that the first secondary of one transformer is in series with the second secondary of the other. One set of interconnected secondaries connects to the line tuning unit via edge connector A24/C24 (high) and A25/C25 (low). The other set of secondaries is connected across balancing resistors R13/R14, which determine the isolation between four-wire ports. For dual-channel transmission, one transmitter connects across the primary of L1, and the other across the primary of L2.
Important Technical Specifications:
- Assembly Numbers:
- 106630-1: Receive 50 Ohms, Send 50 Ohms, Line 50 Ohms
- 106630-2: Receive 50 Ohms, Send 50 Ohms, Line 75 Ohms
- Insertion Loss: Approximately 3.5 dB (input port to line output port).
- Transhybrid Loss: Greater than 25 dB (60 to 500 kHz) with specified termination impedances.
- Power Capacity: 10 Watts rms.
- Two-Wire Line Impedance: 50 Ohms standard (other impedances available on special order).
- Second Harmonic Distortion: At least 80 dB below the fundamental frequency.
- Third Order Intermodulation Products: At least 60 dB below the fundamental frequency.
Usage Features:
- Controls and Indicators:
- J1 (Jumper): Always in the A position.
- Test Points (TP):
- TP3: Line High (orange)
- TP4: Line Low (orange)
- TP5: Receive High (green)
- TP6: Receive Low (yellow)
- TP7: Send High (red)
- TP8: Send Low (white)
- TP5, TP6, TP7, and TP8 are accessible when the module is installed in the chassis. All other controls/indicators are accessible when the module is removed or on a card extender.
Maintenance Features (Replaceable Parts):
- F1: Fuse, SLO-BLO, 10A, 32V, 3AG (Part No. 10758)
- J1: Connector, header, single, 3CKT (Part No. 32802 3)
- L1, L2: Transformer, hybrid, 50 ohm, XMIT (Part Nos. 55768 for 106630-1, 55768/55769 for 106630-2)
- P1: Connector, JK, male, 64 contact, DIN (Part No. 98457)
- R13, R14: Resistor, wirewound, 100Ω, 5%, 10W (Part No. 100 795)
- TP3, TP4: Test point terminal, orange (Part No. 98441 3)
- TP5: Test point, green (Part No. 38116 5)
- TP6: Test point, yellow (Part No. 38116 8)
- TP7: Test point, red (Part No. 38116 2)
- TP8: Test point, white (Part No. 38116 1)
Skewed Hybrid Module
Function Description:
The Skewed Hybrid Module employs two hybrid transformers to connect a transmitter and receiver to a single line tuning port. It offers high signal separation by isolating the local transmitter signal from the local received signal and prevents the receiver's input impedance from loading the transmitter. It also provides impedance matching. Signals can be accepted from an amplifier with a source impedance of 50 Ohms and up to 10 Watts of output power.
The transmitted and received signals pass through a hybrid formed by transformers L1 and L2. These transformers each have two secondaries, interconnected so that the first secondary of one transformer is in series with the second secondary of the other. One set of interconnected secondaries connects to the line tuning unit via edge connector A24/C24 (high) and A25/C25 (low), coupling both the transmitter and receiver to the line tuning unit. The other set of secondaries connects across an internal balancing network (resistors R4 through R11). The coarse balance switch SW1 and fine balance potentiometer R4 adjust the resistance across the transformer secondaries, determining the transhybrid loss.
The transmitter output connects across the primary of L1, and the receiver input connects across the primary of L2. Transmitter output signals are coupled through L1 to the line tuning unit, while incoming signals detected by the line tuning unit are coupled through L2 to the receiver. Transmitted signals are attenuated by about 0.3 dB, and received signals by about 12.5 dB. Signal-to-noise ratios remain unaffected as both signal and noise are equally attenuated.
Important Technical Specifications:
- Assembly Numbers:
- 106625-1: Receive 50 Ohms, Send 50 Ohms, Line 50 Ohms
- 106625-2: Receive 50 Ohms, Send 50 Ohms, Line 75 Ohms
- Insertion Loss (60 to 500 kHz):
- Transmitting: Approximately 0.3 dB.
- Receiving: Approximately 12.5 dB.
- Transhybrid Loss (60 to 500 kHz): Greater than 40 dB with specified termination impedance.
- Internal Balance Range: 0.5 to 1.95 times the specified two-wire impedance.
- Power Capacity: 10 Watts rms.
- Two-Wire Line Impedance: 50 Ohms standard (other impedances available on special order).
- Second Harmonic Distortion: At least 80 dB below the fundamental frequency.
- Third Order Intermodulation Products: At least 60 dB below the fundamental frequency.
Usage Features:
- Controls and Indicators:
- J1 (Jumper): Always in the A position.
- J2 (Jumper): Enables/disables current limiting for the protection circuit. "IN" enables, "OUT" disables.
- J3 (Jumper): Enables/disables 50 Ohm termination. "IN" enables, "OUT" disables.
- SW1 (Switch): Coarse adjustment for balancing network.
- R4 (Potentiometer): Fine adjustment for balancing network.
- Test Points (TP):
- TP3: Line High (orange)
- TP4: Line Low (orange)
- TP5: Receive High (green)
- TP6: Receive Low (yellow)
- TP7: Send High (red)
- TP8: Send Low (white)
- TP5, TP6, TP7, TP8, SW1, and R4 are accessible when the module is installed in the chassis. All other controls/indicators are accessible when the module is removed or on a card extender.
- Receive Port Protection and Termination:
- The receive port includes protection circuitry (transient suppressor CR1, resistor R1) and line termination resistance.
- Jumper J2 bypasses R1 when current limiting is not desired.
- Jumper J3 enables the 50 Ohm termination resistance (power dissipated by termination limited to 1W).
- Protection and termination should be enabled ("IN") on the hybrid in a chassis with a single rear UHF connector, with the received signal wired directly to the receiver.
- If the received signal is sent to a UHF connector on the line I/O (e.g., to another receiver), both termination and protection should be omitted ("OUT") from the hybrid. The termination resistor should follow the line I/O's UHF connector.
- The protection circuit is always enabled on the I/O when connected to the local receiver.
- Termination must never follow any current limit resistance.
Maintenance Features (Replaceable Parts):
- CR1: Suppressor, transient, bidirectional. 75V (Part No. 101473)
- F1: Fuse, SLO-BLO, 10A, 32V, 3AG (Part No. 10758)
- J1-J3: Connector, header, single, 3CKT (Part No. 32802 3)
- L1, L2: Transformer, hybrid, 50 ohm, XMIT (Part Nos. 55766 for 106625-1, 55865 for 106625-2)
- P1: Connector, JK, male, 64 contact, DIN (Part No. 98457)
- R1-3: Resistor, fixed composition, 100Ω, 5%, 1W (Part No. 1009 182)
- R4: Resistor, metal film, variable, 100Ω, 10%, 2W (Part No. 44356)
- R5: Resistor, wirewound, 50Ω, 5%, 2.5W (Part No. 1100 747)
- R6: Resistor, wirewound, 50Ω, 5%, 5W (Part No. 1100 748)
- R7, R8: Resistor, wirewound, 12Ω, 5%, 2.5W (Part No. 1100 745)
- R9, R10, R11: Resistor, metal film, precision, 12.1Ω, 1%, 1/2W (Part No. 1510 2109)
- SW1: Switch, rotary, 1 deck, 6 position (Part No. 44357)
- TP3, TP4: Test point terminal, orange (Part No. 98441 3)
- TP5: Test point, green (Part No. 38116 5)
- TP6: Test point, yellow (Part No. 38116 8)
- TP7: Test point, red (Part No. 38116 2)
- TP8: Test point, white (Part No. 38116 1)
Hybrid I/O Module
Function Description:
The Hybrid I/O module features three BNC connectors, all equipped with spark gap protection devices. The middle port (J2) serves as the line port for both X-Hybrid and Skewed Hybrid modules. When an X-Hybrid is connected, J1 and J3 function as TX (input) ports. When a Skewed Hybrid is connected, J1 is the TX (input) port, and J3 is the RX (output) port.
Maintenance Features (Replaceable Parts):
- The schematic (Figure 7) shows connections to the hybrid module and includes spark gap protection devices (E1, E2, E3) and associated wiring (W1-W6).
To Next Page
Need help?
General
