Philips D1720

The D1720 was a pocket radio manufactured in Hong Kong by the Philips Corporation. In its time, during the late 80s and early 90s, it was an ultra thin AM/FM stereo radio, with ultra light headphones. It was approximately 12 mm thick and took a pair of "AAA" size dry cells to operate. It had volume control sliders for each channel, FM stereo LED indicator, band selector switch, and a power switch. A miniature variable capacitor performed the tuning function for both bands. The radio usually came in silver, black, red, and yellow. The yellow one was part of the Philips "Moving Sound" range.

Review

The headphone amplifier IC is TA7688P, manufactured by the Toshiba Corporation. It was also used in Walkmans, and portable high-end stereo systems, and the sound quality is excellent. If you ditch the supplied headphones, and use something like the Sony MDR-W15, then the sound quality will dramatically improve.

This radio has such a simple design with elegant curves and lines, and for it to be appreciated you need to see it from all angles. Even though the case is plastic and manufactured in Hong Kong, a nice one without scratches would look great.

In this multi-page article, you can see some of the electronic design features, and how they used conventional components to make it.

I just love these wonderful volume control sliders, where each channel has an independent slider control.

Cost / eBay

These were mass-manufactured, however being so popular people usually used them until the headphones broke or they bought the next belt-on gadget to take its place. The price can vary from as little as five pounds upwards, and depends upon the day and the number of radio enthusiasts interested.

I have never had much luck with this one, because the first one I bought had water damage and rust, and the second one had PCB damage from battery electrolyte. I should have enough parts to make a good working one soon. :-)

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