Re: Low Noise Power Supply

Jim Mcilroy


If it doesn't have to be switched mode have a look around for a Kenwood PS-30 which may occasionally be found seconhand from dealers.

These will do 13.8V at 15A continuous and intermittently up to 20A

I have used one for years. They are electrically quiet, and I have also seen them being used to power commercial VHF repeater systems.


Jim  G4EQX

On 18/02/2021 11:26, Colin Ranson wrote:

All, Chris Bartram.


On the subject of noise from a SMPSU – a long time ago I acquired a Farnell 75amp 28volt unit. Its located in my loft at the moment, and is also remotely turned on and off from the shack (long story as to why)   As an experiment last night I connected about 40ft of wire to the + terminal and ran it round the loft.   I could not detect, or see, any increase in noise on any band (IC-7300) 1.8 – 70MHz.  


These PSU’s were obviously made to the enormous price they fetched when new. No doubt proper design and filtering.


I also have an Agilent E3648 Lab PSU in the shack, not sure if SM or Linear but full of digital stuff....    no interference from that either.


Chris, as I mentioned earlier, don’t buy a Nissei MS-1228 ‘Professional’ SMPSU..... outputs loads of crap on HF/Lo VHF. And personally I would not buy one of these ‘tweakable’ SMPSU’s to move sprogs away from the station you want to work.  Had one of these at a club station.... awful !


Best regards


Colin de G8LBS.


Sent from Mail for Windows 10


From: Brian Howie GM4DIJ
Sent: 18 February 2021 10:30
Subject: Re: [UKMicrowaves] Low Noise Power Supply


In message <9b0cfc04-b30d-faba-2395-3d5cba425a26@...>,
Chris Bartram G4DGU <chris@...> writes
>Nothing to do with microwaves, except possibly that it will help me
>sort-out/rationalise my workroom/shack, and thus help hasten my return
>to having an operational station.
>Does anyone have any (polite!) suggestions regarding a low-noise 12V
>20A+ switching PSU?
>Chris G4DGU

I bought a  used HP ProLiant 750W PSU Power Supply   from e-bay last
year to use /P , rather than lugging a heavy linear supply. They come in
at about £12 and easy to mod for 13.8V or you can  leave them at 12V.

Http://  under low cost SMPU

HP ProLiant DL360 G6 750W Power Supply (HSTNS-PD18 version)

They seem quite enough for what I do.

There's plenty of suppliers.

Brian GM4DIJ
Brian Howie


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