The Philco model 610 is an American domestic receiver made in 1935.
It is a 115v mains powered set and is running off an external 240/115v
stepdown transformer. The left control is the Volume On/Off switch, the
centre control is the bandchange switch, and the right control is the 2
position Tone control. The top centre dual knob is the tuning control with
a slow speed planetary reduction drive. The "peephole" dial window is illuminated
with the pointer visible as a shadow. The radio has 2 short wave bands,
and works quite well.
The receiver was purchased in its present state, and it appears as though the case has been restored, and new knobs fitted. The speaker cloth looks original. The only work required was a new rubber mount under the tuning capacitor as 1 of the 3 had disintegrated, and the gang was loose. It also required a new dial light. I replaced the 80 rectifier valve (as it was a small GT style envelope) with the larger G type, to match the other larger style valves. It still contains its original capacitors. There is evidence inside the back that a wasp nest may have been there at one time.
It is a 5 valve superhetrodyne receiver. It uses a steel chassis in a tall wooden cabinet of the "tombstone" shape. The electrodynamic loudspeaker is mounted above the chassis. The circuit uses a 6A7G mixer/oscillator, a 78 I.F. amplifier, a 75 detector/A.F. amplifier, a 42 audio output, and an 80 rectifier. The I.F. is 460kcs, and it covers the frequencies; Band 1, 530-1720kcs, Band 2, 2.3-2.5mcs, Band 3, 5.7-18mcs. The dial is marked with the Police bands, and that would explain the bandspread 2mcs band.