Grundig Satellit 750 AC wall wart hum - can it be eliminated?

[NeedtoKnow2]

I understand that the "best way" to listen to this radio is with battery power. Under most circumstances AC power creates hum or other noise.

But for those of us who insist on plugging it into an AC receptacle via a 6 volt DC wall wart - are there any humless/noiseless options?

Are any 6 volt DC, negative center pin, power supplies known to be "hum free?"

 

[Dirk_SDR]

There are power supplies with the key words "Hifi", "audiophile" or "linear regulated".
6V should be possible, negative center pin is unusual so perhaps you have to invert the voltage DIY.
If you look for another DC plug for soldering, the type is important: 5,5x2,5mm or 5,5x2,1mm or ...

 

[majoco]

Same problem I had with an external supply for my NordMende Globetrotter - the internal one supplied with the radio that sat in the battery tube was hopeless - external ones couldn't supply the current, even a 1Amp hummed when played reasonably loud - problem was the voltage required was 7.5 volts - not common. So I made one - rather larger than I would have liked but it's fully regulated - works a treat.

 

[KK4JUG]

Many European items that use power supplies have center negative plugs. Many of my band's instrument pedals are German-made and center negative. Most are 9V. I usually will simply cut and reverse the output wires. I'm also careful to mark the power supply itself so there won't be any confusion.

 

[Dirk_SDR]

Many European items that use power supplies have center negative plugs. Many of my band's instrument pedals are German-made and center negative. Most are 9V. I usually will simply cut and reverse the output wires. I'm also careful to mark the power supply itself so there won't be any confusion.

Yes, you are right. Some music effect equipment still uses power supplies with negative center pin.
But mostly the center pin is positive.

 

[KK4JUG]

Many European items that use power supplies have center negative plugs. Many of my band's instrument pedals are German-made and center negative. Most are 9V. I usually will simply cut and reverse the output wires. I'm also careful to mark the power supply itself so there won't be any confusion.

I need to correct myself. While they are German-designed, they're still made in China.

 

[w2xq]

I'd get a replacement plug, make up a cable, and buy a small Astron power supply. Probably overkill for you, but I hung 5 or 6 receivers on a 20a power supply. Get a linear power supply, such as one of the first three on this page ( https://www.astroncorp.com/linear-desktop ) sufficient to run all the 12v stuff in your shack. HTH.