Topband: RFI Down Under

[GGLL]

GM. from down under also, but at the other side...

Needless to say, in my country we're flooded with those, non filtered 
power supplies. I think it's to cut $$, the common user does not use AM 
anymore, and day after day ham population decrease... and $o on.

Indeed, the psu pcb is marked with filter components, but they are 
absent. Bridge wires instead.

Just in a very, very few ones they are installed, and even outside the 
pcb, at the mains socket you have filtering components..

You note also manufacturing is cheaper day after day, just try the 
weight of a psu made in 2000 vs. one of the laters. Thinner cabinets, no 
filters, and so on.

So, every time I get an old, discarded psu, I check for this common mode 
inductors, capacitors, varistors, take them off and use to fill the 
blanks in my RFI generator appliances.

Poor of the guy who experiment MF or LF.

I had a LED monitor in my radio shack, 12 V powered, which also add hash 
at 10..24 MHz.
Even supplying it with a car battery, or a linear power supply, adding 
filters at vga cables, here and there, no filter cured the hash.

My solar panel regulator is quiet when recharging the battery, BUT if 
you use any of the two USB ports to charge your cell phone or 
whatever.... well, better turn off the radio.

Printers also have good line filters, old professional switches psu, etc.

Regards
Guillermo - LU5WE.



El 23/11/20 a las 03:16, Phil Hartwell via Topband escribi�:
> G'day All,
> 
> Several months ago I purchased a custom built PC for my shack, from a 
> long established local dealer, as I had used them many times before. I 
> had been prepared to build it myself, but upon investigation I found 
> that the dealer could build it cheaper than I could, plus load and test 
> Win 10, and provide a three year warranty, so I took the easy option. 
> All seemed well and it was successfully interfaced with my new TS-890S. 
> A few days later I turned on an AM radio in the shack and was horrified 
> by severe RFI across the entire MF BC band. My first suspicion was a 
> recently installed broad band modem/router, but that was not the 
> culprit. I traced it to the new PC PSU. I tried ferrites to no avail, so 
> opened up the PSU to find no RFI filtering or transient suppression 
> components whatsoever, despite the PSU having a *_CE label_* on it. The 
> PCB had the RFI component locations marked, but to save a few cents they 
> were omitted, as the country of origin (I won't mention it, we are in 
> enough trouble with them already, they are a bit sensitive to criticism, 
> but you can guess), knows that the Australian regulator does not and 
> cannot enforce RFI compliance due to under-funding by the federal 
> government. They know they can get away with it and flood the country 
> with noise generating rubbish. I doubt they would get away with it in 
> Germany, due to their high standards and hopefully enforcement, but I 
> imagine the majority of countries are in the same boat as Australia.
> 
> Anyway, I removed the IEC socket and fitted an old "Corcom" filter and a 
> varistor, which quietened the beast to my satisfaction. However, I was 
> more than a bit peeved, so fired off a letter to the dealers management, 
> advising them of the non compliant PSU (with a CE label), suggesting 
> they cease selling such equipment and to advise the manufacturer that 
> such rubbish is not acceptable. I also warned them that they might be 
> liable for warranty repairs due to the susceptibility of the PSU to 
> mains disturbances. A few days later a tech called me offering to 
> replace the PSU, I declined saying I had fixed the problem myself, but 
> reiterated my complaint, saying the regulator would take a dim view of 
> such equipment. He had to agree and offered me a further extended 
> warranty, free of charge, which I accepted. I doubt they will accept my 
> advise, but I felt better after my rant.
> 
> Is it any wonder that HF operation is becoming increasingly difficult or 
> impossible in urban areas? I'm lucky to live in an RF quiet rural area, 
> so to preserve that I closely inspect any new equipment my gadget 
> addicted XYL brings home! Apart from seasonal QRN, I hear very well on 
> Top Band, it's frustrating, as I know many others can't hear me, not 
> just because of QRN, but due to their high, local, man made noise level. 
> A very sad state of affairs. I dread the proliferation of cordless 
> charging devices and electric vehicle cordless charging, could be game 
> over!
> 
> GL and 73, Phil VK6GX.
> 
> 
>