Teardown Of Casio Credit Card-Sized Radio

March 26, 2025 by 33 Comments

These days we don’t get too fussed about miniaturized electronics, not when you can put an entire processor and analog circuitry on a chip the size of a grain of sand. Things were quite different back in the 1980s, with the idea of a credit card-sized radio almost preposterous. This didn’t stop the engineers over at Casio from having a go at this and many other nutty ideas, with [Matt] from Techmoan having a go at taking one of these miniaturized marvels apart.

The Casio FM Stereo radio in happier days. (Credit: Techmoan, YouTube)

On the chopping block is the FM stereo device that was featured in a previous episode. Out of the four credit card-sized radios in that video, the one with the rechargeable battery (obviously) had ceased to work, so it was the obvious choice for a teardown. This mostly meant peeling off the glued-on top and bottom, after which the circuitry became visible.

In addition to the battery with a heavily corroded contact, the thin PCB contains a grand total of three ICs in addition to the analog circuitry. These were identified by [Spritetm] as an AM/FM tuner system IC (TA7792), an FM PLL MPX (TA7766AF) and a headphone amplifier (TA7767F), all of them manufactured by Toshiba.

Although [Matt] reckons this was a destructive teardown, we’re looking forward to the repair video where a fresh cell is soldered in and the case glued back together. Continue reading “Teardown Of Casio Credit Card-Sized Radio” →

Card Radios Remembered

March 22, 2025 by 17 Comments

We know how [Techmoan] feels. In the 1980s we had a bewildering array of oddball gadgets and exciting new tech. But as kids we didn’t have money to buy a lot of what we saw. But he had a £5 note burning a hole in his pocket from Christmas and found a Casio RD-10 “card radio” on sale and grabbed it. He’s long-ago lost that one, but he was able to find a new old stock one and shows us the little gadget in the video below.

The card-thin (1.9 mm) FM radio had many odd features, especially for the 1980s. For one thing, it took a coin cell, which was exotic in those days. The headphones had a special flat connector that reminded us of an automotive fuse. Even the idea of an earbud was odd at that time.

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Red and gold bakelite Philco farm radio on a workbench

Hacking A Heavyweight Philco Radio

March 10, 2025 by 6 Comments

There’s something magical about the clunk of a heavy 1950s portable radio – the solid thunk of Bakelite, the warm hum of tubes glowing to life. This is exactly why [Ken’s Lab] took on the restoration of a Philco 52-664, a portable AC/DC radio originally sold for $45 in 1953 (a small fortune back then!). Despite its beat-up exterior and faulty guts, [Ken] methodically restored it to working condition. His video details every crackling capacitor and crusty resistor he replaced, and it’s pure catnip for any hacker with a soft spot for analog tech. Does the name Philco ring a bell? Lately, we did cover the restoration of a 1958 Philco Predicta television.

What sets this radio hack apart? To begin with, [Ken] kept the restoration authentic, repurposing original capacitor cans and using era-appropriate materials – right down to boiling out old electrolytics in his wife’s discarded cooking pot. But, he went further. Lacking the space for modern components, [Ken] fabbed up a custom mounting solution from stiff styrofoam, fibreboard, and all-purpose glue. He even re-routed the B-wiring with creative terminal hacks. It’s a masterclass in patience, precision, and resourcefulness.

If this tickles your inner tinkerer, don’t miss out on the full video. It’s like stepping into a time machine.

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Repairing A 1955 Classic Radio

March 6, 2025 by 8 Comments

We used to say that fixing something was easier than bringing up a design for the first time. After all, the thing you are fixing, presumably, worked at one time or another. These days, that’s not always true as fixing modern gear can be quite a challenge. Watching [Ken’s] repair of an old 1955 Silvertone radio reminded us of a simpler time. You can watch the action on the video below.

If you’ve never had the pleasure of working on an AM radio, you should definitely try it. Some people would use an amplifier to find where the signal dies out. Others will inject a signal into the radio to find where it stops. A good strategy is to start at the volume control and decide if it is before or after that. Then split the apparently bad section roughly in half and test that portion—sort of a hardware binary search. Of course, your first step should probably be to verify power, but after that, the hunt is on.

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Retrotectacular: Ham Radio As It Was

February 21, 2025 by 22 Comments

We hear a lot about how ham radio isn’t what it used to be. But what was it like? Well, the ARRL’s film “The Ham’s Wide World” shows a snapshot of the radio hobby in the 1960s, which you can watch below. The narrator is no other than the famous ham [Arthur Godfrey] and also features fellow ham and U.S. Senator [Barry Goldwater]. But the real stars of the show are all the vintage gear: Heathkit, Swan, and a very oddly placed Drake.

The story starts with a QSO between a Mexican grocer and a U.S. teenager. But it quickly turns to a Field Day event. Since the film is from the ARRL, the terminology and explanations make sense. You’ll hear real Morse code and accurate ham lingo.

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What The Well-Dressed Radio Hacker Is Wearing This Season

February 13, 2025 by 7 Comments

We’ve seen a lot of interest in Meshtastic, the license-free mesh network for small amounts of data over the airwaves. [Ham Radio Rookie] was disappointed with his Meshtastic node’s small and inefficient antennas. So he decided to make what we suspect is the world’s first Meshtastic necktie.

We assume the power is low enough that having it across your thorax is probably not terrible. Probably. The tie is a product of a Cricut, Faraday cloth, and tiny hardware (the Xiao ESP32S3 and the WIO SX1262 board). The biggest problem was the RF connector, which needed something smaller than the normal BNC connector.

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Does A Radome Affect Radio?

January 25, 2025 by 24 Comments

Not too far away from where this is being written is one of Uncle Sam’s NATO outposts, a satellite earth station for their comms system. Its most prominent feature is a radome, a huge golf-ball-like structure visible for miles, that protects a large parabolic antenna from the British weather. It makes sense not just for a superpower to protect its antennas from the elements, and [saveitforparts] is doing the same with a geodesic dome for his radio telescope experiments. But what effect does it have on the received signal? He’s made a video to investigate.

The US military radome is likely constructed of special RF-transparent materials, but this smaller version has a fibreglass skin and an aluminium frame. When he compares internal and external sky scans made with a small motorised satellite TV antenna he finds that the TV satellites are just as strong, but that the noise floor is higher and the frame is visible in the scan. It’s particularly obvious with such small dish, and his planned larger array should improve matters.

We would be curious to know whether an offset-fed dish constructed to minimise ground noise reaching the LNB, would improve matters further. It’s no surprise that the frame doesn’t impede the TV satellites though, as it is many wavelengths wide at that frequency. The video is below the break, and meanwhile, we featured the antenna he’s using here in 2023.

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