The radio described in this post is one of the most desired among antique radio collectors: it is the famous Philco 70, produced by the great American corporation between 1931-32.
This model is one of the most famous and well-known radio ever built, a true icon of vintage radios: who has never seen its distinctive shape on radio books and magazines, or even in a movie set in the ’30s?
Its unequaled design which reminds the architecture of a church in a vague gothic style was the work of the architect Edward L. Combs, one of the Philco designers and author of other masterpieces such as the model 90.
This model had the features of a big console radio, very common in the wealthy America of the ’20s: it has 7 tubes, of the type indirectly heated cathode and 2.5 volt screen-grid: 24A, 24A, 27, 24A, 24A, 47, 80. Electronically, it is a super-heterodyne with a 260 kHz intermediate frequency with a separate triode oscillator (27), and with radio-frequency stage. The output stage is single-ended, using a 47 pentode. As shown in the photos, the radio has a big 3-section variable tuning capacitor made by galvanized steel, a speaker which is clearly derived from the miniaturization of console radio speakers, and a general accuracy of construction. In spite of being a mass-produced radio, Philco managed to build the model 70 with great care and adopting refined technical solutions. The radio has remarkable output power, sensibility and selectivity, and is a good performer also with a short antenna.
The model described in this post has been restored in both the case and the electronics, maintaining the originality of the set: aesthetically, it is a very good shape, with the refinished wooden cabinet, the Bakelite escutcheon and the rosette knobs in good original conditions.
Also internally the radio was in good conditions, with a well-preserved chassis – just a dusting was enough to bring it back to its ancient magnificence.
Repairing consisted only in the replacement of the electrolytic capacitors of the power supply, whereas all the other paper capacitors were left untouched at their place since incredibly still in good working order. After the repair, the radio was perfectly working on the complete standard broadcast band, with great output power.
Another model belongs to our collection, also carefully restored to its original beauty: