The Ultra U506 is a small, table radio in a cream and brown phenolic plastic cabinet. It is typical of many AC/DC sets produced in the later 1940's.
The instruction leaflet with this set indicates that it was sold on 17 November 1949 by the dealer Morgan Evans of Llanarth, Cardiganshire.
The valves, on B8A bases are:
10C1 Frequency changer
10F9 Intermediate frequency (IF=465 kHz)
10LD11 Detector and AF amplifier
U404 Mains rectifier
The circuit is simple and standard. It is a variable mu triode-hexode frequency changer, variable mu pentode IF amplifier, double-diode-triode detector and AF amplifier, beam tetrode output and half wave mains rectifier.
Long and medium wavebands are covered. HT smoothing is by a resistor plus the usual electrolytic capacitors, and the chassis is "live". A tapped mains dropper resistor supplies the valve heaters.
When the set was released in December 1947 it cost Ł13 17s. 6d. plus purchase tax. In June 1948 the price was reduced to Ł13 15s. 4d.
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