[RFI] Noisy or Quiet Power Supplies?

[doc at kd4e.com]

Thanks for the input!

I am hoping to find someone with direct knowledge of this
specific PS.  The $99. sale price is good but not if it is
either unreliable or RFI-troubled.

I will see if I can get an answer from MCM.

doc


> I don't know about that particular switching power supply, but I do know
> that I have done a lot of business over the past 10+ years with MCM, and I
> have found them very good to deal with.  Unless someone specifically tells
> you that the unit is a "screamer", I'd suggest asking the person who takes
> your phone order if you can return it for RFI reasons.  I will guess that
> they will allow that.  It can't hurt to ask.
>
> I have been running the Astron SS-30M for several years now with NO
> problems whatever.  (See QST back in 2002 - can't recall the issue -  for a
> review of the Astron, and other, switching power supplies.  The ARRL did an
> excellent job of testing several popular models - most of which are still
> available.  Read the reviews then buy.  That's why I bought the Astron; it
> was the lowest noise unit they tested.)
>
> A reminder:  although keeping conducted emissions to a low level on the DC
> output lines is important for minimizing noise coupling from a switcher
> supply into the equipment it is powering, it is also important to be
> certain that you do not have any antennas located real close to the shack
> that could pick up radiated emissions from the DC cables or the cabinet of
> the power supply itself.  My HF antennas at the home QTH are more than 50
> feet away from the shack, and all point away from the shack.  I have used
> the Astron on Field Day with HF antennas strung overhead and not had
> problems, so I do think it is a truly excellent unit.  (No, I have no
> vested interest in Astron, but as an EMC engineer, I can tell good design
> when I see it.  Astron does not spare the ferrites in their SS-series of
> power supplies.)
>
> I do own several pieces of Tenma test equipment.  It all works OK, but none
> of what I have is a switcher.
>
> 73, Dale
> WA9ENA
>
>
>> [Original Message]
>> From: doc at kd4e.com<doc at kd4e.com>
>> To:<undisclosed-recipients:>
>> Date: 10/16/2010 10:47:49
>> Subject: [RFI] Noisy or Quiet Power Supplies?
>>
>> Anyone know if these things are RFI-quiet enough to be around
>> a Ham shack?
>>
>> Tenma Heavy Duty 40 Amp Switch Mode Power Supply
>> 72-7665 (727665) | MCM-Tenma  Sale:  $99.
>>
>> http://www.mcmelectronics.com/product/72-7665
>>
>> --
>>
>> Thanks!&   73, doc, KD4E
>> http://KD4E.com
>> Have an http://ultrafidian.com day
>> Defend free speech or lose your freedom.
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>>
>>
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>
>

-- 

Thanks! & 73, doc, KD4E
http://KD4E.com
Have an http://ultrafidian.com day
Defend free speech or lose your freedom.
I don't google I SEARCH! http://ixquick.com