The Johansson KIT 7474L2/2437 is an auto-programming web amplifier intended for combining 2, 3, or 4 terrestrial TV antennas for full HDTV reception. Unlike a passive splitter — which causes a minimum 4dB signal loss when combining two antennas and cannot resolve channels sharing the same frequency — this amplifier uses SMART AMP technology to scan all channels automatically, boost the weakest signals, and deliver uniform output power across all channels at 90dBµV.

The kit consists of the 7474L2 amplifier and the 2437 dual-output power supply. The amplifier supports LTE band re-use (L2: CH49–69, 694MHz–862MHz, switchable), so channels that share the same frequency can be relocated to the LTE band. SAW filters on all four inputs provide built-in anti-5G and LTE protection. The 2437 power supply is wall or DIN-rail mountable and delivers 12V DC over coax with short-circuit protection.

Key Features

• 4 VHF/UHF inputs, 1 output
• SMART AMP automatic channel scanning and equalisation
• Uniform output power: 90dBµV on all channels
• LTE rejection: >40dB (5G, above CH48)
• Adjacent channel isolation: >35dB
• Frequency range: 174–862MHz (VHF Band III + UHF)
• LTE band re-use: L2 = CH49–69 (694MHz–862MHz), switchable ON/OFF
• SAW filters on all inputs for 5G/LTE protection
• Input sensitivity: minimum 40dBµV
• Amplifier power: 12V / 350mA (DC over coax)
• Operating temperature: -20 to +50°C
• DC power over coax — no separate cable to the amplifier needed
• All ports ESD protected
• 2437 power supply: 2 outputs, 12VDC / 400mA, AC input 110–240VAC / 50–60Hz / 6.5W
• 2437 insertion loss: 4–5dB; isolation between outputs: 10dB
• Short-circuit protection and power LED on 2437 power supply
• Wall or DIN-rail mountable power supply

Product Benefits

• Eliminates the minimum 4dB loss that a passive combiner causes when joining two antennas, preserving signal strength
• Resolves same-frequency channel conflicts automatically — channels that would otherwise cancel each other out are relocated to the LTE re-use band
• Fully automatic channel scan on double power start-up means no manual frequency programming is required after installation
• Automatic country channel plan recognition adapts to the local frequency plan without manual configuration
• Adjacent channel isolation above 35dB handles the most difficult near-frequency interference situations
• Built-in SAW filters on all four inputs protect against 5G interference without needing external filters
• DC power over coax simplifies cable routing: only one coax run is needed between the power supply and the amplifier head

Technical Specifications

• 7474L2 — Inputs / Output: 4 inputs / 1 output
• Frequency range: 174–862MHz (VHF Band III + UHF)
• Output power: 90dBµV
• LTE rejection: >40dB (5G, above CH48)
• Adjacent channel isolation: >35dB
• Input sensitivity: minimum 40dBµV
• LTE band re-use: L2 = CH49–69 (694MHz–862MHz), switch ON/OFF
• Amplifier power: 12V / 350mA (DC over coax)
• Operating temperature: -20 to +50°C
• LTE protection: SAW filters on all inputs
• 2437 — Outputs: 2
• 2437 — Insertion loss: 4–5dB
• 2437 — Isolation between outputs: 10dB
• 2437 — AC input: 110–240VAC / 50–60Hz / 6.5W
• 2437 — DC output: 12VDC / 400mA
• 2437 — Mounting: Wall or DIN-rail

Why You'll Love It

• Plug-and-play setup: double power start-up triggers the full automatic channel scan — no laptop or app required
• Combining up to 4 antennas in one pass removes the need to choose between coverage areas
• The 2437 power supply includes short-circuit protection and a status LED, making fault-finding straightforward
• Kit includes: 1x Johansson 7474L2/2437 amplifier kit, 1x manual, 1x wall clamp