Having the same chassis inside as the Ultra TR100 released two years earlier, during this time Ultra took over Pilot and company that started in 1935 in the USA and having links to London where later models were made with UK parts. This set comes from the valve to transistor transition period of the late 1950s when the Japanese and some US companies had changed all their cabinets the plastic and the period of the wooden cabinet maker was drawing nearer. The transition from brown polished wooden radios had been happening with Bakelite from the early 1930s but the equipment for making these cabinets was very expensive compared to using a cabinet maker. Rexine was the answer, cover the wood with a plastic looking material and retain the carpenters workshop. Unfortunately they were quite large units as is the Pilot radio today at 14" wide. The one thing the larger sets had going for them was the better sound quality that can be obtained by a bigger speaker and heavier cabinet. But they just wouldn't fit in your pockets like the plastic ones. The American Regency TR1 was the first on the market in about 1954, the UK a little later (1956) with the Pam 710, then owned by Pye company.
The transistors used in this set are the PX types (top hat) and requiring a centre split 9 volt supply, giving 4.5 volts to each of the output transistors and producing a high level of volume using only 6 transistors, 3 RF and 3 audio.
The biggest drawback with this model is the 2 x 4.5v batteries, so I decided to centre tap a 6 x 'AA' battery box, the being more readily available 1 1/2v types. After converting the clips the radio worked fine and no work was necessary apart from a quick clean over. I decided to fit 2 yellow LED's behind the tuner window.
The view of the inside shows that there is lots of free space inside, I may fit LED's to the dial later perhaps. It had a car aerial socket on the rear, (TV type) Most early portables were also aimed at the car user market. Although the picture is upside down you can see the chassis has the Ultra model number on the label. I don't think many were produced as this is the first I have ever come across. I've included the circuit and service information if anybody has one to repair.
The earlier Ultra version
No comments:
Post a Comment