RFI noise

[William Carver]

I lost a PC power supply, ordered a pair of replacements from Tiger
Direct. They were neither half-KW monsters nor their cheapest supply. It
had VDE/UL/FCC stickers, ALL of the agency certifications.

Suspecting a line surge had killed the original supply I decided to
stuff some MOV at the input connector of the new supplies before I even
installed them. I opened the cases and found The PCB silkscreen showed
RFI filter components, but none were installed: the board had direct
wire jumpers from power in to the switching circuits.

I connected it to the motherboard and found switcher EMI over the HF
spectrum. For the record, my shop is in the garage, powered from
seperate breakers, shop strips have 30A/230V encapsulated line filters
and their own MOV. The radio gear was in a bedroom with coax feedlines
goubg directly outside, buried for 250 feet to a yagi 50 feet in the
air. No open wire feeders, no longwires direct to the shack.

It seemed pretty clear the supplies had passed agency approvals with the
filter components in place, but once they had the sticker they stopped
putting those parts on the board.

Bill - W7AAZ


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[N2TK]

Bill,
I have had good success with PC Power & Cooling supplies. Have replaced all
of the cheaper PC supplies with theirs. Got rid of the noise.
http://www.pcpower.com/index.html


N2TK, Tony


-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of William Carver
Sent: Thursday, September 24, 2009 3:09 PM
To: [hidden email]
Subject: [Elecraft] RFI noise

I lost a PC power supply, ordered a pair of replacements from Tiger
Direct. They were neither half-KW monsters nor their cheapest supply. It
had VDE/UL/FCC stickers, ALL of the agency certifications.

Suspecting a line surge had killed the original supply I decided to
stuff some MOV at the input connector of the new supplies before I even
installed them. I opened the cases and found The PCB silkscreen showed
RFI filter components, but none were installed: the board had direct
wire jumpers from power in to the switching circuits.

I connected it to the motherboard and found switcher EMI over the HF
spectrum. For the record, my shop is in the garage, powered from
seperate breakers, shop strips have 30A/230V encapsulated line filters
and their own MOV. The radio gear was in a bedroom with coax feedlines
goubg directly outside, buried for 250 feet to a yagi 50 feet in the
air. No open wire feeders, no longwires direct to the shack.

It seemed pretty clear the supplies had passed agency approvals with the
filter components in place, but once they had the sticker they stopped
putting those parts on the board.

Bill - W7AAZ


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[Alan Bloom]

On Thu, 2009-09-24 at 13:08 -0600, William Carver wrote:
...
> It had VDE/UL/FCC stickers, ALL of the agency certifications.
...
> It seemed pretty clear the supplies had passed agency approvals with the
> filter components in place, but once they had the sticker they stopped
> putting those parts on the board.

You should report them to the FCC.  They could get in big trouble if
they really did that.

Al N1AL


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[k1tl]

I installed a 350w PS from Antec in one of my computers and the noise
disappeared.

One other computer, I installed a Corcom 6EF1 RFI module at the AC input and
that cleared up the computer hash on 30m. This drove me nuts for about two
years as I was hearing this warbling hash going up and down the 30m band.
Thought it was some kind of digital noise from somplace in EU. After
flipping breakers in the house, noticed that the 2nd floor breaker stopped
the noise...narrowed it down to the computer ps.

Tom/k1tl...

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[David Gilbert]

I've bought the parts for several high-end computers from Tiger Direct
and haven't any problem with power supplies (or much of anything else,
for that matter), but I always buy the power supplies made by Ultra (a
solid brand name) because I like their modular cable system.  Ultra even
offers a full lifetime warranty now if you register it online, and their
reputation for addressing user problems is very good.

73,
Dave   AB7E



N2TK wrote:
> Bill,
> I have had good success with PC Power & Cooling supplies. Have replaced all
> of the cheaper PC supplies with theirs. Got rid of the noise.
> http://www.pcpower.com/index.html
>
>
> N2TK, Tony
>
>  
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[Bill Steffey NY9H]

going for glorosio for 17 meters,,,,  while split ...
I think i'd much prefer  the front of the two concentrics to be  AF
main ( bottom) and AF sub  top ....
as I find myself constantly  reaching behind to change the level of
the sub channel while hunting ......

someone recently suggested a menu setting to flip something ,,,,to
attain the same goal.
having the balance in front  .( i think )...or maybe both AFs in front .....

AND yes I also peeked at the backplane to see abt a pcb mod... which
would be more appropriate in SW.

I reverted to another older rig where the two rcvrs have separate
pots  and the af is in front of the rf....
seems more intuitive,,,, and easier,.

k3    #49

bill

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[Bill Steffey NY9H]

At 02:08 PM 9/24/2009, William Carver wrote:
>I lost a PC power su

filter parts missing from production power supplies,,,,probably after
agency certifications.


RSGB's magazine has been on this issue for many months with pictures  etc....
I believe that they had not much concern from their OFCOM on the issue.

I would think the FCC would not take well to being "frauded" ...in
this fashion.

I'd copy the list with your brand names & model numbers,, do copy the
RFI list ,,,,
and let the folks at Tiger Direct they got shipped 'defective"
fraudulent goods as well...

back to Ft5ga

bill  
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[Stewart Baker]

Bill,
In the UK it is the case that many SMPSU's have, once CE certification has been obtained
been manufactured in volume with the input filter parts omitted.
These are in the main imports from Tiawan and China.

These non-compliant PSU's have been brought to the attention of our regulator Ofcom,
which dragged it's heels, and has finally - done nothing.

In the UK we have TSO's (Trading Standards Offices) which are locally based.
They are tasked with enforcing vast amounts of EU legislation with little funding.
The EMC Directive to which these PSU's must comply comes within their remit.

Trading Standards were recently involved in a investigation into a Taiwanese company
that was importing SMPSU's that breached a number of CE marking requirements,
including the EMC one.

Although substantial evidence was gathered (at some expense to TS) which in the case
of EMC compliance with EN55022 showed the PSU's to be over the limit by  >30dB,
no prosecution has taken place.

This was due to poor wording which crept in when the UK regulations were transposed
from the EU ones. A total waste of time and money...

Trading Standards have stated, that until the UK EMC Regulations 2006 are amended,
they will not take on any further EMC complaints.

This leaves the door wide open for any company that wishes to avoid the extra expense
of CE compliance to do what it wants.

73
Stewart G3RXQ

On Thu, 24 Sep 2009 15:32:20 -0500, Bill NY9H wrote:

> At 02:08 PM 9/24/2009, William Carver wrote:
>>I lost a PC power su
>
> filter parts missing from production power supplies,,,,probably after
> agency certifications.
>
>
> RSGB's magazine has been on this issue for many months with pictures  etc....
> I believe that they had not much concern from their OFCOM on the issue.
>
> I would think the FCC would not take well to being "frauded" ...in
> this fashion.
>
> I'd copy the list with your brand names & model numbers,, do copy the
> RFI list ,,,,
> and let the folks at Tiger Direct they got shipped 'defective"
> fraudulent goods as well...
>
> back to Ft5ga
>
> bill
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

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[David Cutter]

A different approach might work better:  what these firms are practising is
fraud or misrepresentation and we get a lot of that over here.  Passing it
off as something which it is not as any other consumer goods is illegal.
It's also illegal to use an agency sticker like that.  Over here we have the
Sales (Descriptions) Act, but it's still a headache getting anyone to do
anything about it, but it is another lever against the seller and/or
importer.

David
G3UNA

>I lost a PC power supply, ordered a pair of replacements from Tiger
> Direct. They were neither half-KW monsters nor their cheapest supply. It
> had VDE/UL/FCC stickers, ALL of the agency certifications.
> > .
>
> It seemed pretty clear the supplies had passed agency approvals with the
> filter components in place, but once they had the sticker they stopped
> putting those parts on the board.
>
> Bill - W7AAZ
>
>

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[Matthew D. Fuller-2]

On Thu, Sep 24, 2009 at 03:17:26PM -0400 I heard the voice of
N2TK, and lo! it spake thus:
>
> I have had good success with PC Power & Cooling supplies. Have
> replaced all of the cheaper PC supplies with theirs. Got rid of the
> noise.

I second this.  Also, even ignoring RFI completely, I only use PCP&C
supplies in my systems, because they have a long history of being
built *solid*.  Reliable, clean output, and will give the amps it's
spec'd at.  Would you put a power supply on your rig that "regulates"
at 5% or worse across its load range?  So don't do it to your computer
either   :)


--
Matthew Fuller, N3TZJ
<[hidden email]>
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