National Panasonic T-100D

The T-100D, also known as T100D, was a 9-transistor world band radio manufactured in 1966 by the National Panasonic Corporation of Japan at their Matsushita Industrial Complex. It was a 4-band battery powered shortwave (SW) receiver for the high-end of the market. It became popular due to its high quality sound produced by a twin speaker system providing separate bass and treble. In 1966, a Class-B push-pull output stage using a matched pair of germanium transistors (2SB324) was a good as it got and many high-end products of that time had it. The good thing about this design is that the Japanese kept improving the components with better output transformers and speakers; consequently, many products of that period had identical output stages and produced very high quality sound.

The National Panasonic Model R-450 had similar characteristics including a two-speaker system, but lacked the chrome frame at the front. Its case was wood with hardboard back cover. The R-1400 also had similar features such as the bands and the folding square aerial. The National Panasonic R-100B was also very similar with a chrome handle and chrome front frame. It had control knobs that were vertically oriented on the right hand side, and it could receive power through a built-in mains transformer, as well as batteries. The National Panasonic T-100Y was identical looking except it had an additional FM band and a telescopic aerial.

Usually when people migrate, the one radio station they want to stay in touch with is BBC World Service on the SW band, and the T-100D radio was excellent for that purpose. This radio also covers the entire shortwave spectrum, which is usually 1.6 MHz to 30 MHz above the MW band.

• SW1 1.6 MHz to 4.5 MHz
• SW2 4.5 MHz to 12 MHz
• SW3 12 MHz to 26.1 MHz

The plastic case has a covering of this interesting textured material. It took a long time to clean with a brush and soapy water to bring it back to its original condition. In the 60s, this would have been a very popular colour.

In this radio, the shortwave coverage divides into three bands, and in the time-honoured tradition, they start with the 187 m wavelength, which is the end of the medium wave (MW) band. As you can see, each band starts where the other ends, hence this straightforward scheme was the easiest to understand.

• MW 57.1 m to 187 m
• SW1 187 m to 66.7 m
• SW2 66.7 m to 25.0 m
• SW3 25.0 m to 11.5 m

Konosuke Matsushita founded National Panasonic in 1918. Starting as a one-man repair shop, it quickly became Japan’s number one manufacturer of electrical and electronic products. In the 1963 issue of Fortune magazine Matsushita Electrical ranked 37th.

I just love this wonderful teal type colouring, which is very reminiscent of the 60s modern look. The switch controls the power to illuminate the tuning dial. In the following pages of this multi-page article, you can see the bulbs and the dial.

Cost / eBay

The T-100D is an early radio not often seen often on eBay. These radios were hand constructed and are highly collectable in any condition, and many hobbyists enjoy renovating them back to their former glory. The electronic design is a straightforward superheterodyne, which should be simple to repair, however replacement germanium transistors will be difficult to find.

You can expect corrosion of the spring clips in the battery compartment, dead germanium transistors, dry solder joints, pitting of the chrome, cracked plastic, yellowing of tuning dial, and plenty of grime. However, all of this is repairable to make a good working radio that would look nice in your modern living room. The price depends greatly upon condition and the number of interested people; however, I have never seen one go cheap.

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