This trader advert from April 1950 is from the most famous 50's portable maker; Roberts Radio.  A plain advert with so little text - is perhaps the sign of the arrogant attitude of the dominant name in quality and reliability.  From memory the centre tuning knob is geared down so that several rotations are necessary to span the tuning range.  Notice the "engineers" accurate measurements down to an eighth of an inch!  However, notice the inconsistent use of the apostrophe on Roberts'.

The New "Junior" Portable.

Price: £17.17.3 (including purchase tax).
Complete with batteries and water-proof zip carrying cover.
Size: 9 5/8" x 5 7/8" x 6 3/8", weight only 10½lb.

Roberts Radio Co. Ltd.
Creek Road
East Molesey
Surrey
Telephone: Molesey 2684