Jim (and all),
It's a "WAC Lighting Company" model EN-12PX-AR. Specs on the case
say input is 120v 50/60Hz, output is AC 12V at 20kHz, 150W load max.
I did a quick Google check and it seems to be a pretty common PS.
No FCC tag (unless it was on the side mounted to the wall, which I'd
rather not remove unless/until I'm going to replace it.
--
73,
David, K2DBK
On Fri, 26 Nov 2004 12:05:12 -0800, Jim Lux <jimlux@earthlink.net> wrote:
>
>
>
> ----- Original Message -----
> From: "K2DBK" <dkozinn@gmail.com>
> To: <towertalk@contesting.com>
> Sent: Friday, November 26, 2004 11:47 AM
> Subject: Re: [TowerTalk] Halogen Bulbs - 1.8 Mhz RFI
>
> > I discovered that I've got one of the "bad" types of LV power supplies
> > for some of my lights, which, unfortunately, does a really nice job
> > of generating RFI over a very broad spectrum. (I don't think it
> > actually makes it as far as the 2m band, but it does show up on 50mHz
> > and lower.) Fortunately, the lights it powers aren't the primary
> > lighting for any of the rooms that they are in, so we try to keep them
> > turned off when I'm at the radio.
> >
> > The power supply itself is in an easily accessible location in the
> > basement, and I wouldn't mind replacing it myself. Has anyone had any
> > experiences with non-noisy supplies like this that they'd recommend?
> >
> > 73,
> > David, K2DBK
>
> More to the point, David, what's the make and model of the noisy supply (and
> is there a FCC sticker/label on it)?
>
> I've noticed that my laptop cranks out a LOT more RFI when plugged in than
> when running on batteries (discovered this when sweeping for noise with a
> PCR1000). It's a DELL PA-5 putting out 19V at 3.16 A.
>
>
> >
> > On Fri, 26 Nov 2004 11:41:59 -0700, Bill VanAlstyne, W5WVO
> > <w5wvo@cybermesa.net> wrote:
> > > FWIW, my experience with switching LV power supplies of various kinds
> has been
> > > that the RFI they generate is common-mode. I've had no luck suppressing
> any
> > > noise from them with differential filters. That's just an anecdotal data
> point,
> > > nothing more -- not a theoretical opinion. :-)
> > >
> > > I've also had the experience with LV halogen lights that some of the
> switcher
> > > PSes clearly do not meet any standard for RFI, generating S9+ hash over
> the
> > > entire HF-VHF spectrum, while many others are completely clean. The
> difference
> > > is always huge -- they either do it or they don't. Makes me think that
> some
> > > manufacturers simply figure to get away with it and save big money on
> filtering
> > > components -- and apparently do so with relative impunity, since the
> devices are
> > > on the shelves and people buy them. After all, what percentage of
> typical
> > > consumers would even know or care about HF-VHF RFI from halogen PSes?
> Much less
> > > than 1%, probably much less than 0.1%, is my guess. The cost of
> refunding to
> > > their retailers for the occasional return is probably far less than the
> NRE and
> > > component costs of doing it right would have been.
> > >
> > > Bill / W5WVO
> > >
> > >
> > >
> > >
> > > Jim Lux wrote:
> > > > ----- Original Message -----
> > > > From: "Jim Brown" <jim@audiosystemsgroup.com>
> > > > To: <towertalk@contesting.com>
> > > > Sent: Thursday, November 25, 2004 12:16 PM
> > > > Subject: Re: [TowerTalk] Halogen Bulbs - 1.8 Mhz RFI
> > > >
> > > >
> > > >> On Thu, 25 Nov 2004 14:46:07 -0500, Floyd Sense wrote:
> > > >>
> > > >>> I doubt that there is much you can do to silence them.
> > > >>
> > > >> I agree that there are probably switching supplies causing the
> > > >> problem, but I wouldn't give up on fixing the problem without trying.
> > > >>
> > > >> There are three basic ways the RF can get out -- on the power line
> > > >> wiring, on the low voltage wiring to the lamps, and direct radiation
> > > >> from the power supply if it is unshielded. Direct radiation you
> > > >> probably can't fix except by replacing the supply. A standard, good
> > > >> power line filter should eliminate what is coming via the power
> > > >> line, and a multi-turn choke around a big ferrite, possibly in
> > > >> combination with a capacitive
> > > > filter
> > > >> should be able to kill what is on the low voltage wiring.
> > > >>
> > > >> You will need at least 8 turns around the typical big toroids to
> > > >> make an effective choke for 1.8 MHz. That choke should also work on
> > > >> 80 meters, but may be running out of effectiveness by 40 meters and
> > > >> above.
> > > >>
> > > >> 73,
> > > >>
> > > >> Jim Brown K9YC
> > > >>
> > > >>
> > > >
> > > > Depending on where the noise is coming from, a common mode filter
> > > > (i.e.running a bunch of turns of the twoconductor wire through a
> > > > ferrite)
> > > > might not help a lot. You might need a decent differential mode
> > > > choke/capacitor filter on the output of the low voltage supply. Put
> > > > the
> > > > choke first (so the capacitive load doesn't screw up the switching
> > > > regulator).
> > > >
> > > > Also, if you have a LV halogen scheme with the two "rails" from which
> > > > the
> > > > lamps hang, the rails can serve as a nice radiator of differential
> > > > mode
> > > > noise.
> > > >
> > > > By the way, if the halogen power supply is a low voltage device, it
> > > > would
> > > > need to comply with EN55011 (the EU equivalent of Part 15). Perhaps
> > > > the
> > > > problem is really that the halogen supply isn't working to spec?
> > > >
> > > >
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