Patent GB-911073-A (GB)
Title: Improved carrier wave signal-distributing circuits
Inventor: GABRIEL RALPH PARTON
IPC: H04H60/22
Filed: 1959-01-16
Abstract: 911,073. Distributing music &c. COMMUNICATIONS PATENTS Ltd. Jan. 16, 1959, No. 1616/59. Class 40 (4). In a wired distribution system in which it is desired to make a charge in respect of the reception of a certain programme or programmes, a plurality of sets of signals each pertaining to a different programme are distributed over a common circuit as modulation on carrier waves of different frequencies, filters being provided at each subscriber's premises which divert the frequency band or bands pertaining to the certain programme or programmes into a particular path or paths, the or each such path including a switch operated under the control of coin-responsive or other metering means whereby the required charge may be collected on a prepayment or postpayment basis. The system illustrated in Fig. 4 pertains to the distribution of four television programmes, two of which (A, B) originate from radio broadcasting stations while the other two (C, D) originate from cinematograph films or tele-cine apparatus at the central station of the system. The four programmes are modulated on four carrier waves and distributed over the coaxial cable 19 to subscriber's receiving equipments each including a standard television set 20. The inner conductor of a coaxial drop-in 24 is connected to the filter means 23 in the coupling unit 21 of each subscriber, the outer conductor being connected to the metal case 22. The " free " programme signals of A and B are directed by the filter 23 to conductor 27 leading directly to the set 20; the C signals to conductor 28; and the D signals to conductor 29. Use of the set in respect of C and D signals is controlled by a metering arrangement including a coin-switching equipment as described in Specification 699,409, having a pair of contacts 31 which may be bridged by a coin 32 of the correct denomination fed into the coin-guide 30 by way of a slot (not shown) in the case 22. The change-over switch 35 manually operated by knob 37 enables the subscriber to choose either programme C or D for reception. The switch 38, ganged with switch 35, connects winding 33 or 34, respectively, via low-pass filter 39 to the inner conductor of cable 19. At the central station 50 c/s alternating current is supplied to the primary of transformer 42, one end of the secondary winding of which is connected via low-pass filter 44 to the inner conductor of cable 19, and the other end of which is connected to the movable arm of the three-position switch 45. At the end of a particular item of programme C the arm of switch 45 is moved to the right, whereupon the winding 33 is energized at all subscriber's premises at which that item has been received. Similar movement of 45 to the left at the end of a D programme item energizes winding 34 at all premises at which the D item has been received. Energization of 33 or 34 moves the coin-guide 30 in the direction of the arrow, whereupon the coin 32 is deposited in a collecting box (not shown). Actuation of knob 37 to change from C to D or vice versa causes, via cam 48 and camfollower 49, movement of the coin-guide 30 to deposit any coin 32 present in the guide, and payment must be made afresh for the new programme selected. Specifications 696,584, 765,103 and 885,877 also are referred to.