Plugpack switchmode power supplies...how noisy?

[VK3LU]

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

[VK3RX]

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.

[VK3LU]

Thanks Damien,
Looks like I will have to suck it and see!

73
Nev

[VK3ALB]

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

[VK3LU]

Hi Lou
Good idea. The Jaycar part number is MP3490.
Has anyone used one and if so, is it quiet?

Nev

[VK2ZIW]

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

[VK3LU]

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

[VK3YCQ]

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

[VK3LU]

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