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+--- Thread: Plugpack switchmode power supplies...how noisy? (/thread-405.html)
Plugpack switchmode power supplies...how noisy? - VK3LU - 24-09-2017
Has anyone had any experience with the above with regard to rfi?
I have my eye on a 12v 2.5 amp one that Jaycar sell that suits my needs and would like to know if it is likely to be noisy.
73 Nev
RE: Plugpack switchmode power supplies...how noisy? - VK3RX - 28-09-2017
I don't have experience with the Jaycar one, but some "wall warts" are noisy (and some poorly regulated) and some aren't.
It's a case of try it out, and return if noisy.
RE: Plugpack switchmode power supplies...how noisy? - VK3LU - 29-09-2017
Thanks Damien,
Looks like I will have to suck it and see!
73
Nev
RE: Plugpack switchmode power supplies...how noisy? - VK3ALB - 29-09-2017
Perhaps if you post the catalog number someone else out there may be using one and advise how it works for them?
Sent from my SM-T350 using Tapatalk
RE: Plugpack switchmode power supplies...how noisy? - VK3LU - 29-09-2017
Hi Lou
Good idea. The Jaycar part number is MP3490.
Has anyone used one and if so, is it quiet?
Nev
RE: Plugpack switchmode power supplies...how noisy? - VK2ZIW - 30-09-2017
Hi Lou,
5V 1A, 12V 1A etc.. I haven'v found a quiet one yet.
It's all about the long wire you attach to it:
Plug-Pak------radio------long wire(coax)------Antenna
Here, I put a clip-over ferrite suppressor over the DC wire with as many turns as possible.
ADSL router plug-paks are a big big problem with the router network cables and phone line all radiating!!
It's NOT fun. (HF that is)
Alan VK2ZIW
RE: Plugpack switchmode power supplies...how noisy? - VK3LU - 30-09-2017
Thanks Alan
I have a couple of clip on ferrites so I will be prepared.
If the plug packs are that noisy then it seems like they are not made to any specification.
We will see what eventuates.
73
Nev
RE: Plugpack switchmode power supplies...how noisy? - VK3YCQ - 01-10-2017
Hello Nev
Try aiming your antenna at some of the cheaper LED downlight 'electronic transformers'. Going by what I have observed, particularly regarding noise level indicated on the s-meter on 2 metres, there is no regulation of electrical standards any more. Specification? What a joke.
73s , Ian
VK3YCQ
RE: Plugpack switchmode power supplies...how noisy? - VK3LU - 13-11-2017
I have answered my own question.
I purchased an MP3490 (12v 2.5A) from Jaycar. It emits a slight amount of noise at the lower end of HF.
I wound as many turns of the generous 12v lead as possible around an FT114-43 I had lying around and connected a .01uf cap across the output.
Noise gone! Simples.
Just gets warm powering the FT817nd
Nev