Monoblock LNB

Lore & Background

Monoblock LNBs emerged as a specialized type of low-noise block downconverter, combining several LNB units and a DiSEqC switch into one housing. This integration allows automatic addressing by any DiSEqC 1.0 or higher receiver, and in some cases by ToneBurst/MiniDiSEqC. However, they are only available for satellites with fixed outer spacings of 3, 4, 4.3, or 6 degrees. Most commercial receivers support DiSEqC 1.0, enabling dynamic switching among up to four satellites as the user changes channels via a remote control.

In Europe, monoblock single, twin, and quad LNBs for the Ku band are available with a predefined 6-degree spacing for Astra 19.2°E and Hot Bird 13°E. In March 2007, CanalDigitaal in the Netherlands introduced the Duo LNB for simultaneous reception of Astra 19.2°E and Astra 23.5°E with a 4.3-degree spacing, intended for 60 cm dishes rather than the larger 80 cm or 1 m dishes typically required. Triple monoblock units exist for three satellites, such as Hotbird 13°E, Eutelsat 16°E, and Astra 19.2°E, or for other positions with the same 3°+3°=6° spacing. Four-feed monoblock LNBs enable reception from four satellites, for example Eurobird 9°E, Hotbird 13°E, Astra 19.2°E, and Astra 23.5°E with a total spacing of 14.5°.

Multiband monoblock LNBs combine Ku-band LNBs with Ka-band or C-band LNBs. Two monoblock LNBs can be connected to one dish using multi-satellite techniques, though results may be sub-optimal or yield low signal levels; separate single-feed LNBs often provide better signal levels. Monoblock LNBs can be connected via cascading DiSEqC switches or directly to twin tuners with separate inputs.

Reader's Guide

The significance of the monoblock LNB lies in its ability to consolidate multi-satellite reception into a single, user-friendly device, eliminating the need for multiple separate LNBs and external switches. By integrating a DiSEqC switch, it allows automatic switching between satellites as the user changes channels, simplifying the user experience. Its legacy is evident in the widespread availability of monoblock LNBs for common satellite clusters in Europe, such as the 6-degree spacing for Astra and Hot Bird, and the introduction of the Duo LNB for tighter 4.3-degree spacing. However, adoption faces barriers: current DiSEqC technology could theoretically support up to 16 or 64 satellite positions, but market demand, narrow directional beams from broadcasters, and the need for special dish shapes limit development. Designing thin monoblock LNBs with 2°, 1°, or 0.5° spacing remains a challenge, and low public awareness of multi-feed multi-satellite capabilities, along with incompatibility with satellite channel routers (SCR) or unicable LNBs in single-cable distribution, further restricts uptake. For pay-TV systems, users must choose between unicable LNBs or multi-feed monoblock LNBs, often requiring multiple cables for multi-room setups. Despite these limitations, monoblock LNBs remain a practical solution for receiving signals from multiple satellites without a motorized dish.

Did You Know?

• Monoblock LNBs typically integrate 2–4 LNB units and a DiSEqC switch into a single device.
• The Duo LNB, introduced in March 2007, was designed for 60 cm dishes, unlike most monoblocks that require 80 cm or 1 m dishes.
• Four-feed monoblock LNBs can receive signals from four satellites, such as Eurobird 9°E, Hotbird 13°E, Astra 19.2°E, and Astra 23.5°E.
• Multiband monoblock LNBs combine Ku-band with Ka-band or C-band LNBs.