5.3- Pictorial applications of the classic circuits
illustration of the valve set used in the radio receiver model 2515 made in Holladn by Philips. The arrow shows the rectifying valve model 506
One of the first radio receivers for operation in 110-220V, AC, model 2515 made in Holland by Philips showing (a) its rectifying valve type 506
Communication receiver model GR-78, mde in the USA by Heath. The arrows shows in its front panel the automatic volume control.
Block diagram of the Hi-F audio amplifier model 80 AZ made in the USA by Fischer. The dotted line shows the allocation of the negative feedback section in its circuit.
Radio receiver model 3000-1 made in the USA by Zenith. The arrow shows in the front panel its automatic frequency control
close up of the radio receiver model Royal 3001-1 showing the automatic frequency control
Model 80 AZ Hi-Fi audio amplifier, manufactured in 1957 by Fischer Company, EUA.
Radio receiver model GR-78 block diagram showing in the dotted square the automatic volume circuit .