Description
General Instrument Magnitude MMI+ 410802-03 Multiplexer Modulator Interface 1U
The General Instrument Magnitude MMI+ (part number 410802-03) is a 1U rackmount Multiplexer/Modulator Interface designed for use in professional cable television and digital broadcast headend systems. Manufactured by Magnitude Compression Systems, Inc. (a General Instrument brand), the MMI+ serves as the central signal routing and interface hub between transport stream multiplexers and RF modulators in a Magnitude headend chassis. It manages the flow of compressed digital video streams — including DVB-formatted content — between multiplexer outputs and downstream modulator inputs.
Specifications & What's Included
- Model: MMI+ (Magnitude MMI Plus)
- Part Number: 410802-03
- Manufacturer: Magnitude Compression Systems, Inc. / General Instrument
- Form Factor: 1U Rackmount
- Power Input: AC 100–240V, 60–50 Hz, 0.5–0.3 A (universal input)
- Fuse: 1A, 250VAC
- AC Connector: IEC C14 inlet with rocker on/off switch
- Rear Ports (8 total):
- A MUX IN — DB-15 connector
- B MUX IN — DB-15 connector
- MODEM OUT 1 — DB-15 connector
- MODEM OUT 3 — DB-15 connector
- MODEM OUT 4 — DB-15 connector
- MODEM OUT 5 — DB-15 connector
- DVB MODEM OUT — DB-25 connector
- DVB MODEM IN — DB-25 connector
- Front Panel: ALARM CABLE (DB-25), HSSI I/O connector, EXT SYNC (BNC), LED status indicators (MUX, DVB, SS, CLK, PLL, FRM, OLL)
- DIP Switch Control: Internal Mode Switch Selector, Internal Frequency Switch Selector (5–50 MHz range), MPEG-2/CSI Packet Length selector, HSSI Loopback settings, EIA-449/DCE emulation mode
- Country of Manufacture: United States
- Included: Unit only; no cables or accessories
Applications
The Magnitude MMI+ was a key component in General Instrument's Magnitude digital cable headend platform, which was widely deployed by cable television operators in the mid-to-late 1990s as the industry transitioned to MPEG-2 digital video compression. In a Magnitude headend, the MMI+ sits between the transport stream multiplexers and the QAM or DVB modulators, routing and interfacing the multiplexed digital bitstreams for modulation onto the cable plant. The HSSI (High-Speed Serial Interface) port connects to compatible multiplexers, while the multiple modem output ports feed individual modulator inputs. The DVB modem ports support DVB-formatted transport stream paths, and the EXT SYNC BNC allows synchronization to an external reference clock. The front-panel LEDs provide at-a-glance status for the MUX, DVB, clock, PLL lock, framing, and output-link conditions. Today this equipment is relevant to operators and technicians maintaining legacy Magnitude headend systems, as well as researchers and collectors of early digital cable infrastructure.
This General Instrument Magnitude MMI+ Multiplexer/Modulator Interface (410802-03) has been inspected and is in good used condition. The chassis and panels are clean with only light surface scuffing consistent with normal rack service. All rear connectors — including the HSSI I/O, alarm cable port, modem output ports, DVB modem ports, and EXT sync BNC — appear intact with no bent pins or visible damage. The front-panel LED indicators and DIP switch access panel are present. The IEC power inlet and fuse holder are in good shape. Please view our photo set and contact us if you have any questions. Please note: We have multiple units in stock — yours may not be the one shown in the photos, however, it will be similar in condition and function.
Warranty Information
Additional Information
Brand: |
General Instrument |
Model: |
MMI+ |
MPN: |
410802-03 |
Secondary Model: |
Magnitude MMI Plus |
Type: |
Multiplexer / Modulator Interface |
SKU: |
39795 |
Condition: |
Used – Inspected |
Form Factor: |
1U Rackmount |
Power Requirements: |
AC 100-240V, 60-50 Hz, 0.5-0.3 A |
Fuse Rating: |
1A, 250VAC |
Interface Type: |
HSSI I/O, DVB Modem, EXT Sync, Alarm Cable |
Number of Ports: |
8 rear ports: A/B MUX IN, Modem OUT 1/3/4/5, DVB Modem OUT/IN |
Connector Types: |
DB-15, DB-25, BNC (EXT sync), IEC AC inlet |
Front Panel Indicators: |
MUX, DVB, SS, CLK, PLL, FRM, OLL LEDs |
DIP Switch Control: |
Internal mode, frequency, packet length, loopback selectors |
Compatible With: |
General Instrument Magnitude headend systems |
Manufacturer: |
Magnitude Compression Systems, Inc. |
Country/Region of Manufacture: |
United States |
Seller Notes: |
Unit only; no accessories included. Inspected and in good condition. |
Condition Notes: |
General Instrument Magnitude MMI+ 410802-03 Multiplexer/Modulator Interface. Inspected and in good used condition. Chassis is clean with light surface wear. All connectors appear intact. No accessories included. |
