[Elecraft] (OT) - Unplanned Discovery

Sun Nov 19 21:11:32 EST 2017

Hi Barry,

I wasn't the one who experienced the epiphany; have to lay that at Stan's
feet.   :)

Frankly, it's not a big problem for me. However, it did connect a couple
dots in that I was at my brother-in-law's house operating on the battery
whilst visiting. I remarked that the noise floor was very low and just
attributed it to his QTH.   Never connected the fact that perhaps it was
just the local noise sources and I should be less concerned about QRM from
the neighbors and neighboring rooms, and more about what I was feeding the
rig and the other sources in the room.

I will now be spending some time rearranging things to try this out and get
my noise floor down even further.

On Sun, Nov 19, 2017 at 20:39 Barry <k3ndm at comcast.net> wrote:

> Rich,
>      You just discovered the problem with switching power supplies. I'm
> unaware of any computer power supply that isn't a switcher, but for most
> 12 volt needs an analog supply should fix the problem. The only downside
> that I can see is weight; analog supplies can be a bunch heavier, but
> they are RF quiet.
>
>      There some quiet switchers out there. You just need to do some
> research to discover those. One that is quiet is the Tentec. It is
> actually an Astron that Tentec did some work on. I think the one
> Elecraft sells is quiet. Bit, you really need to investigate before
> buying a switcher.
>
> 73,
> Barry
> K3NDM
>
> ------ Original Message ------
> From: "rich hurd WC3T" <rich at wc3t.us>
> To: "stan levandowski" <sjl219 at optonline.net>
> Cc: Elecraft at mailman.qth.net
> Sent: 11/19/2017 7:31:48 PM
> Subject: Re: [Elecraft] (OT) - Unplanned Discovery
>
> >Wow.
> >
> >Going to try that.   Thanks for this great post.
> >
> >On Sun, Nov 19, 2017 at 19:23 stan levandowski <sjl219 at optonline.net>
> >wrote:
> >
> >>Most people on this Reflector are well educated and intelligent.
> >>Apparently, I'm the exception because this one got by me.  I'm only
> >>owning up to this in the hope that it might help someone else on the
> >>Reflector.
> >>
> >>For the last couple of years I've been bothered by a high background
> >>noise level.   It happened on my K1, K2, K3, KX2 and KX3.   I
> >>attributed
> >>this to the fact that my antenna has been in my attic for the last
> >>fifteen years and propagation hasn't been good lately.
> >>
> >>
> >>I just got official permission from the HOA to install an end fed wire
> >>outside.  I was thrilled.  I put it up.  The darn thing wasn't any
> >>better than the attic doublet.  Noisy as heck!  What a letdown!
> >>
> >>
> >>So I'm laying in bed last night reflecting on how my little KX1 was
> >>the
> >>only Elecraft radio that never had noise problems and seemed to have a
> >>receiver quieter than my K3.
> >>
> >>
> >>Whoa!  The KX1 always ran on batteries...could it be?????
> >>
> >>
> >>I just took delivery on a brand new Kx33 Low RFI power supply a couple
> >>days ago. It was advertised in the last QST.   Previous to that, I've
> >>been using a Samlex 1235M.  For the heck of it,  I connected my K2 to
> >>an
> >>SLA battery and the noise was still there.  But when I disconnected
> >>the
> >>Kx33 power supply from the wall, the noise level dropped dramatically.
> >>Then I switched to the Samlex and the noise came back.  Back on the
> >>battery, the noise dropped again as long as the power supplies were
> >>unplugged and dead.
> >>
> >>
> >>I have a laptop next to the computer.  When I pulled the plug on the
> >>laptop supply, the rest of the noise went away.  I was down to S0/S1
> >>and
> >>CW signals were popping out all over the band again.  Running the
> >>computer on its internal battery did NOT contribute any noise.  It was
> >>the computer power supply.
> >>
> >>
> >>Now that I am totally on batteries, I also appear to be immune from
> >>both
> >>the gas furnace and the dishwasher motor both of which caused me
> >>problems when using the AC supplies.  YES, I HAD CHOKES ON ALL
> >>SUPPLIES,
> >>CABLES, WIRE.
> >>
> >>
> >>I've been on the air all day with my new outside antenna, on battery
> >>power,  making contacts near and far and I feel like I've hit the
> >>jackpot.  Since I'm totally QRP and CW, being limited to batteries is
> >>not an issue.
> >>
> >>
> >>If you're going to check your own supplies out, remember they've got
> >>to
> >>be OFF/UNPLUGGED from the wall. Just disconnecting them from the
> >>radio/computer isn't enough.  It's RF.
> >>
> >>
> >>73, Stan WB2LQF
> >>
> >>
> >>
> >>
> >>
> >>
> >>1
> >>
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> >>
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> >
> >--
> >---
> >72,
> >Rich Hurd / WC3T / DMR: 3142737
> >PA Army MARS, Northampton County RACES, EPA-ARRL Public Information
> >Officer
> >for Scouting
> >Latitude: 40.761621 Longitude: -75.288988  (40°45.68' N 75°17.33' W)
> >Grid:
> >*FN20is*
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> >
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>
> --
---
72,
Rich Hurd / WC3T / DMR: 3142737
PA Army MARS, Northampton County RACES, EPA-ARRL Public Information Officer
for Scouting
Latitude: 40.761621 Longitude: -75.288988  (40°45.68' N 75°17.33' W) Grid:
*FN20is*