![]() ![]() Germanium transistors are no longer made, so if you have to replace them you’ll have to find some new old stock or salvage them from other similar radios. ![]() Inductors don’t fail outright, but their values can drift and cause the radio to go out of alignment.Īside from mechanical issues if the radio has a tuning arrangement that’s more complicated than a knob that’s directly connected to a polyvaricon capacitor (a type of variable capacitor that’s common in those radios it has metal plates that are separated by thin plastic sheets), the most likely failure points are electrolytics (already mentioned) and the transistors. Electrolytic capacitors are another matter they are likely to need to be replaced if the radio contains any. They can fail if exposed to excessive voltage or current, or if they are physically damaged, but none of those things is likely to happen inside a transistor radio. Resistors and ceramic capacitors rarely fail. As best as I can remember, consumers didn’t clamor for lead-free solder and little or no evidence surfaced to show lead contamination in potable water. In Europe, the “Greens” played upon environmental fears, pushed legislators to eliminate lead, and dismissed the need for a scientific understanding of heavy-metal pollution (if any). Much of the push to eliminate lead from solder, though, stemmed from the public perception of hazardous wastes as portrayed in the news stories I mentioned above. Granted, disposal and salvage techniques in third-world countries, where such studies are unlikely to occur, probably causes local pollution of water, soil, and atmosphere. ![]() The ban on lead in electronic solder caused the most controversy because as far as I can tell, no research showed environmentally significant amounts of lead leaching from discarded electronic equipment into groundwater in Europe, Canada, or the US. Questioning some current dogmas is verboten. Posted in classic hacks, Repair Hacks Tagged am, germanium transistors, repair, transistor radio Post navigationĮxcerpt from a long article from a dead link which, luckily, I printed to PDF. Who knew that the track from a modern component could be transplanted into one from the 1960s? All isn’t over though, for the volume pot is also kaput. A lot of fault-finding ensues, and perhaps with a little bit of embarrassment, he eventually discovers a blob of solder shorting a collector resistor to ground. Injecting a signal reveals that the various stages all work, but that mixer isn’t oscillating. The devices are a little archaic by today’s standards, with comically low-gain germanium transistors and passives from the Ark. It’s an extremely conventional design of the era, with a self-oscillating mixer, 455 kHz IF amplifier, and class AB audio amplifier. has a Philips radio from we’re guessing the later half of the 1960s which didn’t work, and we’re along for the ride as he takes us through its repair. Thus it’s also not a staple of the repair bench anymore, where fixing a pocket radio might have been all in a day’s work decades ago now they’re a rare sight. The humble transistor radio is one of those consumer devices that stubbornly refuses to go away, but it’s fair to say that it’s not the mover and shaker in the world of electronics it might once have been. ![]()
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