serial Nr.4380
Console floor standing valve radio 240 Volts AC 50 Hz long
and medium wavebands. This handsome model designed by R D Russell
(see below) was first produced in 1937 it has 5 valves plus magic eye
tuning indicator (Mazda types AC/TP, AC/VP2, AC/HLDD, AC/4PEN, UU4 AND
AC/ME). A schematic diagram can be found here. The
tuning mechanism needed re-stringing and apart from replacing the low
voltage cathode bypass capacitor on the output stage, inserting a new
dial bulb and a new mains cable nothing else seemed necessary other
than cleaning the switch contacts and valve pins and bases. I energised
the set at a low voltage and gradually increased until Lo and Behold I
could tune in stations on both long and medium wavebands. Not bad for a
70 year old set?
This radio is one of four which were given to a charitable company Furnishaid Limited
situated in Great Yarmouth.The aims of the company are to provide
recycled furniture to people on low income and to provide training
opportunities for people in refurbishment of furniture. As these were
unsuitable I made a donation and have added them to my collection.
View of interior
The rectangular box on the left houses two electrolytic capacitors (which I have now replaced) and the inductor in the centre forms part of the audio filter circuitry. You might observe that the set has been modified in the past, there is a rectangular "RadioSpares" 125 kc/s IF can adjacent to the original cylindrical IF can under the tuning indicator. I guess that the secondary of the original transformer had gone open circuit and one coil of this transformer is now capacitively coupled to the original. Currently a MHD4 and a AC5/PEN are fitted in the last two stages.
contents of the rectangular box
a closer view of the tuning mechanism and magic eye.
The dial and the name plate on back cover. This picture was taken before I had replaced the thread which should run in front of the drum scale.
The underside of the surprisingly clean chassis.
The chassis must have been used for other designs as it is well endowed with unused holes. The wave change switch is on the right and the three position one in the centre is for the tone control filter. The set has tuned aerial, and tuned grid so is equipped with a triple gang variable capacitor.
The dial stringing mechanism.
This has now been restrung with nylon twine.
The mains energised loudspeaker.
The electromagnet or field coil is wired in series with the high tension supply to the radio and its inductance together with another choke on the chassis and two electrolytic capacitors provide smoothing to the DC supply.
History
Frank Murphy started Murphy Radio in a rented factory in
Welwyn Garden City and the first radio was produced in the summer of
1930. Murphy wanted his radios to be simple, affordable, reliable and
to look and sound good. The radios although fairly conventional were
always stylishly housed. The cabinets were designed by leading
industrial and furniture designers of the day including R D Russell
and Eden Minns who were on the team of the well renowned
furniture firm founded by Gordon Russell. More information
about the latter can be found on the website describing the museum www.gordonrussellmuseum.org/
Murphy Radio continued in business until 1970, though from 1962 it was
owned by Rank-Bush. Much more information about the firm can be gleaned
from "The Setmakers" A history of the UK radio and television industry.
BREMA 1991. These two websites are also well worth looking at:
www.murphy-radio.co.uk/
and www.classicwireless.btinternet.co.uk/
Detailed technical information on the servicing of Murphy receivers was
only supplied to accredited agents. Presumably this was intended to
ensure that repairs were carried out properly.
