Masthead Amplifier Power Unit L4425

This small linear mains power supply is designed to inject DC power into the coax cable of a VHF/UHF radio or TV receiver to power one or two masthead amplifiers, such as Belling & Lee Model L4424, located near the antenna.

The amplifier is claimed to cover "all VHF and UHF channels".

Nominal output 24 V DC at 35 mA. As the power supply is unregulated the output voltage can rise to 32 V on no load. The DC power is applied to the 'IN' terminal which receives the RF signal from the amplifier. No power is applied to the 'OUT' terminal from which the RF signal is sent to the receiver.

Power consumption <5 VA. The label on the unit specifies a mains power input of 220 V 50 Hz. The label on its box specifies 200-240 V 50 Hz. The connection diagram supplied with the unit indicates 200-240 V 50 Hz or 110-120 V 50 Hz.

The label glued inside the cover of the unit shows how the two primary windings of the transformer can be wired in series for a 220 V supply or in parallel for a 110 V supply by resoldering the connections.

The unit is marked Made in Holland.

Here you find 7 models, 5 with images and 0 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
All listed radios etc. from Belling & Lee, Ltd.; Middlesex