Question about old "Solid State" radios

[thunderlight]

I have some old "solid state" radios that I have obtained from flea markets. They plug in. They run fine, but I have been unplugging them when I turn them off. They don't seem to be overheating or anything of that nature. Is unplugging them unnecessary or is it a good idea just to be on the safe side?

These are all transistor / "solid state" radios, not tube based radios from the days, probably early 1960s] when they were labeled as "solid state" or indicated how many transistors they had. They are generally GE radios.

Thanks.

 

[Flying Turtle]

I grew up with radios like those and some old tube models, too. I don't think they were energized by just being plugged in. They probably should not be warm at all when turned off, but I could be wrong. Better safe than sorry.

Geoff

 

[Kilovolt]

Solid state circuits operate at low voltage DC, usually below 12 V. When the unit is plugged in the only live component is the transformer (220/12 or 110/12). No problem whatsoever when the transformer is new and its insulation in good shape. In an old unit the insulation could be a bit damaged and I feel it is wise to unplug the radio when not in use.
What do I call old? Say 15 years or more....

 

[Steel and Light]

I would agree with Flying Turtle and Kilovolt. I had a new wall wart transformer overheat on me once which was defective. Could heat coffee on it. Not a comforting situation. After seeing that transformer overheat I run my old radios only off batteries.

Run 'em off batteries or put 'em on a powerstrip that you can switch off. Sleep better at night.

 

[lctorana]

+1 on the above comments, but there's also something else as well.

In solid state radios that are AC/Battery operated, the switch is often downstream of not just the transformer, but also the rectifier and filter capacitor. Just like a DC wallwart, really.

It is the strain on the latter, which can dry out prematurely, resulting in hum and noise, which is the biggest problem with leaving the receiver plugged in.

But for practical purposes, whether you turn it off at the power point or the receiver depends upon how accessible the power point is, how long it is turned off for, and how well the receiver's on/off switch works.

 

[thunderlight]

Just wanted to thank everybody for the responses. I guess I will continue to unplug them or put them on a powerstrip.