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Dave Plowman (News) Dave Plowman (News) is offline
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Default Fifty year-old Sanyo transistor radio still works perfectly - should I be surprised?

In article ,
Jeff Liebermann wrote:
What is the most likely failure mode of similar radios - dry joints?


If the radio only plays oldies and 1950's rock-n-roll, you have a
problem.


Oh I dunno. Better than a lot of modern stuff.

Dry joints? I've never had to lubricate my solder connections.


It's what describes a failed solder joint as well as anything - they can
look sort of dried out.

In order of frequency:
- Leaky batteries and corrosion damage.


That can kill a new one too.

- Grease on moving parts (tuning capacitor, volume pot, on-off switch)
has dried out.


Can't see dried out grease on a tuning capacitor stopping it working.

- Bad electrolytic caps


- Loudspeaker coil rubbing on magnet. Warped cone.


Same with that.

- Carbon comp resistors changing value.


- Difficulty finding schematics and docs.


They're usually so simple and basic you can wing it. And older stuff
didn't tend to have maker's special part numbers on components.

- Package leakage on the old round cylindrical xsistor packages.


Not seen that one. Aren't they glass encapsulated?

- Tiny xformer wires corrode.


- Crumbling plastic parts, rotting fake leather, peeling chrome
plating, peeling labels, and faded decals.


Again, most of these are cosmetic. Will still work, though.

- Rubber embitterment, especially the power cord.


PVC insulation was pretty common 50 years ago on hook up wire.

--
*The closest I ever got to a 4.0 in school was my blood alcohol content*

Dave Plowman London SW
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