I was always certain that it was a switcher but some models are
oddly RFI-quiet and others a nightmare.
I was hoping someone might recognize it and have direct knowledge.
I have owned analog supplies in the past and have no problem owning
one again, problem is there is no Ham flea or fest within 100 miles
of the Savannah/Statesboro/HIlton Head area where one is likely to
find one.
The seller wrote "I have not done any RFI testing per say, seems
fine on vhf uhf scanning and no prob on the few hf freq i use."
I asked about proximity of antennas and gear and specific freq
and mode but no answers.
WDYT?
doc
> I've said it before and I'll say it again: unless a power supply is
> designated specifically for communications applications, assume that it is
> NOT "clean enough" for communications usage. The unit in question is
> almost surely a switcher, and if intended for commercial applications, it
> will only meet FCC Part 15 Class A emission specs, which are several dB
> worse (higher) than the Class B requirements for computers and digital
> equipment used in the home. (Note that the seller is including shipping in
> the $50 price - that tells me that the unit is light weight, virtually
> guaranteeing it to be a switcher.)
>
> For truly "clean" power, get a "hernia-maker" - meaning a linear power
> supply, not a switcher. You only have to worry about 60 or 120 Hz hum and
> ripple with those. If you don't want big iron like that, then stick with
> the select group of switchers that are designed for communications
> applications. Those units will exceed performance of FCC Class B equipment
> by controlling both the radiated and conducted emissions. Yes, you will
> pay more, but you get what you pay for.
>
> If you watch closely, there are surplus equipment dealers (and people at
> hamfests) who sell off big linear power supplies very cheaply. They were
> the norm 20 or 30 years ago, and you can probably get one for under $50.
> You'll want to find it locally, however, as these babies usually weigh 40
> pounds or more when you start talking 50 amps (or greater) output current.
> Unless malfunctioning, they usually deliver clean power to the loads.
>
> 73, Dale
> WA9ENA
>
>
>> [Original Message]
>> From: doc@kd4e.com<doc@kd4e.com>
>> To: RFI List<rfi@contesting.com>
>> Date: 11/5/2010 9:35:04
>> Subject: [RFI] Anyone know if this 12v ps is RFI-clean?
>>
>> Anyone know if this 12v ps is RFI-clean?
>>
>> "12 Volt 47 Amp Power supplies"
>>
>> See picture here:
>> http://swap.qth.com/view_ad.php?counter=866425
>>
>> It looks like some sort of modified surplus server PS.
>>
>> I have asked the seller a couple of times but no clear
>> answer yet. Does it look familiar to anyone?
>>
>> --
>>
>> 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
>> _______________________________________________
>> RFI mailing list
>> RFI@contesting.com
>> http://lists.contesting.com/mailman/listinfo/rfi
>
>
>
--
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
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