[RFI] periodic peaks in the spectrum

[Don Kirk]

Hi Gary,

You certainly may use the link to my tuned loop webpage.  I’m sure it’s not
nearly as well balanced as your design (especially as you get up higher in
frequency like 28 MHz), but it still does a decent job for DFing.  Also
would be easy to just add a choke on the feedline using 31 material to
improve balance but I’ve never needed perfect balance when out hunting with
this antenna and use it as is.

I’ve noticed many folks spending a lot of time analyzing their RFI spectrum
plots, but not going the next step and building a DF antenna and that’s why
I suggest antennas that might not be perfect but are certainly adequate for
tracking down RFI and easy to build.  In all honesty I’m now using untuned
loops in most cases unless the signal can’t be detected when using them and
then I drag out my tuned loops that offer higher gain.  But now my go to
antenna is my portable flag due to it’s unidirectional properties, but on
very low frequencies (like 160 meters) I sometimes need to use the tuned
loop to hear the weakest of RFI.

Once again you addressed very important issues in your design, but I’m
concerned that some hams are intimidated by all but the simplest of designs.

73,
Don (wd8dsb)

On Thu, Jul 22, 2021 at 6:16 PM Gary Johnson <gwj at wb9jps.com> wrote:

> Good work as usual, Don. I'm all for simple! I'd like to include your link
> below on my RFI page. This is exactly the kind of tool that the members of
> our local clubs can benefit from as they discover that S9 is the new S3.
>
> 73,
> Gary NA6O
>
> From: Don Kirk <wd8dsb at gmail.com>
> Subject: Re: [RFI] periodic peaks in the spectrum
>
> Hi Jim,
>
> I wanted to follow up regarding the link that you provided to the NA6O
> tuned loop.  While it has some nice features, I'm concerned it still might
> be a little too complicated (intimidating) for folks just starting out and
> thought I should share an alternative design that I use to show how easy it
> can be.  Here is a link to one of my tuned loops that's just about as
> simple as it gets for a tuned loop, and it covers 7 to 32 MHz with good
> bi-directional properties throughout.
> https://sites.google.com/site/smalltuneddfloop/home
>
>
>
>