Paul Christensen wrote:
> I have come to rely on
> one indispensable tool to locate these noise sources: A Palomar LA-1 loop
> antenna. The tropical band plug-in loop covers the lower bands through 6
> MHz with razor-sharp directivity.
> Another tool I use with the LA-1 is an SDR-IQ receiver connected to my
> netbook PC and Elecraft K3's I.F. port. The SDR-IQ functions as a spectrum
> analyzer on the netbook PC -- and its powered by the netbook USB port. A
> 14.4VDC gel cel powers the K3. I just throw it all into a Klein
> electricians bag and start roaming on foot. >
I have a K2 and a softrock sdr, perhaps I can borrow a laptop.....
> In addition to a rise in noise floor, you'll often see switching peaks every
> 30 kHz to perhaps 100 kHz, depending on the switching frequency of the
that is why I ask the group about this noise, I am familiar with the normal
'every so many kc' type switching supply noise. But this solid noise floor,
noise, is something new to me. I wasn't relating it to a switching supply as it
didn't either sound like what I am use to, nor had the every so many kc
> No doubt a high-quality loop antenna can be home-brewed. However, I have so
> many projects in the fire that I need to know when to just order something
> and the LA-1 has been an absolute blessing. However, the LA-1 is no longer
> made by Palomar. But the good news is that Palstar makes a near-identical
> The schematics are identical to the LA-1, but with a few improvements. I
> just purchased their version of the tropical loop antenna since it resonates
> to 7500 kHz. I have a new switch mode noise source only on 40m that the
> LA-1 loop cannot tune since it stops resonating at 6000 kHz. So, I am
> hopeful the Palstar loop will stay part of my RFI/EMI detection kit.
wow, I might could afford the tropical loop antenna,
but the $300+ unit it works on is certainly out of my price range, oh well.
GB & 73
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