ATX PC PSU - RF quiet ones?

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VK2GOM
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ATX PC PSU - RF quiet ones?

Post by VK2GOM » Tue Jun 23, 2009 9:17 pm

My home built desktop PC PSU has started making noise on a few of the HF bands.

Even in standby, when the PC LED blinks at about 1Hz, I get 1Hz duty pulses of hash, up to about S5, depending on actual frequency.

Can anyone recommend a source (I daren't say make/model - most are unbranded) for a proven RF quiet ATX form PSU?

73 - Rob VK2GOM

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VK2FLAW
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Re: ATX PC PSU - RF quiet ones?

Post by VK2FLAW » Tue Jun 23, 2009 10:01 pm

I've got a Corsair VX550w in my computer that sits next to my FT-857D with no issues at all.
I got mine from PC Case Gear, not cheap, but I needed aquality one to drive my video card properly.

I would expect any of the brand name devices, would be pretty good on emmissions, but the generic PSU's may be a bit iffy.

That being said, my RF problems are with the monitor I'm using, which puts a dirty signal right in the 15m WSPR frequency...

Anybody know what the LCD's are like for emissions?


Rob
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VK4QB
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Re: ATX PC PSU - RF quiet ones?

Post by VK4QB » Wed Jun 24, 2009 9:05 am

Hi Rob,
I'm running an ACER AL1916 LCD monitor and it has some LF interference at the refresh rate 100 hz or so. otherwise it doesn't seem to have anything. I have a Toshiba laptop Tecra 8000 for PSK and other digital modes alongside my HF/vhf transceiver with no interference. Some do, so don't evidently . My 14v 20a power supply is a home brew and was built from a PC power unit with no noise. No difference between it and batteries. Anything that has hi volts such as a monitor is a big suspect for generating RFI.
Brian 4QB :D

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Re: ATX PC PSU - RF quiet ones?

Post by VK4QB » Wed Jun 24, 2009 9:25 am

Hi Rob 2GOM,
Your problem is in the 24/7 power supply very small ps within the main one) ie the one that supplies power to the sensors. I would not suggest you fix it. If you can get some kindly supplier to loan you several of different makes to try would be the go. Tell him your interference problem tho. and the reason why you want to try different makes. You may not get many makes as usually the supplier sticks to one brand. Most of the power supplies are short of input line filters (less cost) .The older models were better in this respect
Brian 4QB

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Re: ATX PC PSU - RF quiet ones?

Post by VK4APN » Wed Jun 24, 2009 10:55 am

VK2GOM wrote:My home built desktop PC PSU has started making noise on a few of the HF bands.

Even in standby, when the PC LED blinks at about 1Hz, I get 1Hz duty pulses of hash, up to about S5, depending on actual frequency.

Can anyone recommend a source (I daren't say make/model - most are unbranded) for a proven RF quiet ATX form PSU?

73 - Rob VK2GOM
I put a Thermaltake Fanless supply in my shack computer - electrically ( 3.5mhz -1296mhz) and acoustically noise free. The heatsinking is a work of art, however the trade off is that it protrudes about 75mm out from rear of case. In tropical north queensland the ambient temp is always high 20's early 30's - it has been 100% reliable for the last 3 years so far.
Paul vk4apn

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Re: ATX PC PSU - RF quiet ones?

Post by VK2GOM » Wed Jun 24, 2009 10:10 pm

Thanks for the replies chaps.

The fanless supply sounds interesting, and the idea of trying a few PSU's to see what works is a good one too, if the supplier in amenable to that. Even if it means buying them all, and returning the ones I decide against.

73 - Rob VK2GOM

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