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Hi Frank.

That's what I did to start with...I took an old 5 volt phone charger and used it. But then I was having drift problems with the U3S? - it was gradually increasing frequency with use, ending up about 100Hz high from the dial frequency -? and finally discovered that my '5 volt' charger was producing 6.68 volts ...very stable, but very high!

Changing that out for the one I mentioned earlier, which was very steady at 5.01 volts by my meter, fixed my drift problem.

Roger

G3YTN

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Roger Hill
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On 2018-01-01 15:33, Frank W1FRA wrote:

For years, I have gone to the local Transfer Station, ie the Dump, and simply collected cell phone chargers, all 5VDC, and especially the newer Motorola ones, very stable. Free, get to know the people working there, and they will even save them for you. And free.

?

I especially like the ones that are used with Fisjer Price toys. They are rugged, and very stable.

?

Frank? ?W1FRA

On Mon, Jan 1, 2018 at 10:25 AM, Roger Hill <rhill@...> wrote:

Hi Vince

I used this Raspberry Pi psu from Amazon.


I cut the micro usb plug off the end, and also used a 4700uF capacitor across the power terminals inside the U3S case. It worked fine.

I have since replaced it with a home brew LM317 regulator arrangement, so I now feed the U3S with 12volts from my 'used for everything' power supply, and regulated it to 5 volts. That also works well, even though the LM317 gets quite hot.

What that also does is let me use the 12V supply to feed the BS170's, but I have not done that yet.

Roger
G3YTN

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Roger Hill
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On 2018-01-01 14:46, V Zecchinelli wrote:

Can anyone suggest a reliable/stable 5dc P/S for U3S?

73 N1VIN? Vince