[Vintage Engr]

I used to work for The Rank Organistion, in the Top Rank Television division.

I used to install these systems, amongst other things.
We had an engineering agreement with Rediffusion, and used a similar system to them, but on different frequencies for TV distribution in hotels.

As well as distributing the TV signals at what was known as 'System Frequency', the audio was carried on the same pairs as the RF, at a nominal 50v.

This works the same as tradititional 100v line audio distribution, but the lower level was used so as not to cook the vision inserts.(Attenuators/ filter chokes etc).

We fitted Bed-head panels, some with TV & some with only radio.

The unit was simply a selector switch system, accessing each audio /vision pair. This was then fed to the bed-head speaker, or TV speaker, which incorporated a 50v line matching transformer. There were often local 'In-house' generated audio programmes, as well as TV replayed from banks of U-Matic recorders.

We used to fit these all over the world, as well as hotels in the U.K.

David.