[RFI] CARRIER ON 40-METERS

Mon Jan 30 20:30:11 EST 2023

Hi Don,

Yes, I do use the technique you mentioned with my tuned loops but it’s
amazing how much and quickly the angle changes (or possibly polarization).
I often use that technique when listening to AM broadcast stations using my
tuned loops as well as ferrite bar antennas when I don’t have my portable
flag handy.

P.S.  so far it’s somewhat uncanny how close in direction this signal is to
the one in Colorado from last year that Alan and I mentioned, but more
headings (with more precision) are definitely needed.  My quick heading
this evening is very close to what I measured on the previous Colorado case.

Don wd8dsb

On Mon, Jan 30, 2023 at 8:13 PM AA5CT <jwin95 at yahoo.com> wrote:

> re: "Tuned loops did not work well obtaining a heading on the signal
> because tuned loops have very little directional properties for high
> arrival angle signals which we were often encountering on 40 meters."
>
> I see this complaint all the time. Consider the below as a method to avoid
> that issue.
> The video was on 80 meters, but, I have used the same technique for 40
> meters.
> Rapid back and forth motion while listening to the audio level is the key
> to this
> technique; one is looking for the usual null when the loop plane is normal
> (at 90 degs) to the incoming signal's AZ and EL angles. IF you also know
> how high the reflective layer is, one can also make a distance estimation
> given
> the elevation angle.
>
>
> https://rumble.com/vo0ao5-looking-at-incoming-angle-of-80-meter-signals.html
>
> de AA5CT Jim
>
>
>
> On Monday, January 30, 2023, 6:50:56 PM GMT-6, Don Kirk <wd8dsb at gmail.com>
> wrote:
>
>
> Back in April 2022 there was a carrier on 40 meters for many weeks as I
> recall.  TDOA was said to not work well because the carrier was constant
> whereas they said you needed the carrier to be on and off (I have no idea
> when TDOA works well and when it does not work well).  I was able to
> provide a heading from Indiana using my portable flag that turned out to be
> within +/- 5 degrees of the actual location which turned out to be in Alma
> Colorado and it turned out to be a summer home of a ham who had remote gear
> located at his cabin and somehow the transmitter got locked on.  Another
> ham actually took to the sky in his airplane trying to DF the signal using
> DF gear in his airplane but it was the FCC that actually located the
> source.  Tuned loops did not work well obtaining a heading on the signal
> because tuned loops have very little directional properties for high
> arrival angle signals which we were often encountering on 40 meters.  My
> portable flag did the best because it still provided reasonable front to
> back properties at the high arrival angle we were often dealing with.
>
> I just did a quick check of the 7.195 MHz carrier at about 7:30 pm EST with
> my portable flag and I can actually hear it with the portable flag just
> fine without any preamp from my home in Fishers Indiana.  I used a preamp
> to get enough signal strength so I could use the crude S meter on my
> portable receiver, and doing a very quick reading I obtained a heading from
> Indianapolis of approximately 265 to 270 degrees give or take a little
> bit.  It's very cold outside right now so I did not spend any time trying
> to get an accurate heading, I just wanted to see what general direction it
> was coming from.  I was not totally out in the open (I was standing pretty
> close to my house), so I will try and get a better heading when time and
> weather conditions permit.
>
> Just FYI,
> Don (wd8dsb)
>
> On Mon, Jan 30, 2023 at 6:06 PM Don Moman VE6JY <ve6jy.1 at gmail.com> wrote:
>
> > the source is likely from North America (or any other country that uses
> 60
> > hz power)  as the carrier has 120 hz power supply sidebands...
> >
> > On Mon, Jan 30, 2023 at 3:59 PM Michael Carter <Mike.Carter at unh.edu>
> > wrote:
> >
> > > If my reading of that table from the source
> > > Joe linked is correct, the China transmitter
> > > on 7.195 MHz has a TX power of 50 watts.
> > > Seems unlikely to provide S9 + 10 dB signal
> > > or larger in west central US......
> > >
> > > Mike, K8CN
> > > ________________________________
> > > From: RFI <rfi-bounces+mike.carter=unh.edu at contesting.com> on behalf
> of
> > > David Eckhardt <davearea51a at gmail.com>
> > > Sent: Monday, January 30, 2023 5:52 PM
> > > To: Joe <nss at mwt.net>
> > > Cc: rfi at contesting.com <rfi at contesting.com>
> > > Subject: Re: [RFI] CARRIER ON 40-METERS
> > >
> > > CAUTION: This email originated from outside of the University System.
> Do
> > > not click links or open attachments unless you recognize the sender and
> > > know the content is safe.
> > >
> > >
> > > I would rule out either of these two sources.  It is strong with slow
> > > ionospheric fading indicating only one skip zone.  Certainly not
> > > characteristic of Chinese or German signals in the middle of the
> > afternoon
> > > on 40-Meters.
> > >
> > > Dave - WØLEV
> > >
> > > On Mon, Jan 30, 2023 at 10:42 PM Joe <nss at mwt.net> wrote:
> > >
> > > > According to these folk it's Germany or China.
> > > >
> > > >
> > >
> >
> https://nam12.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.freqspotter.com%2Fsearch.php%3Fsearch_for%3Dguide%26q%3D3%26order_by%3Dcallsign%26page%3D45%26order_direction%3DASC&data=05%7C01%7Cmike.carter%40unh.edu%7C26a8ef3f122e41c3051a08db0314c5e6%7Cd6241893512d46dc8d2bbe47e25f5666%7C0%7C0%7C638107159972664361%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=mxIzPgYi3nT84MZeuzbbeK3zX3BKeJujf%2Fs8blpDi28%3D&reserved=0
> > > >
> > > > Joe WB9SBD
> > > >
> > > > On 1/30/2023 4:36 PM, Wes Stewart via RFI wrote:
> > > > >  Using my Perseus it's peaking -70 dBm on my 40-meter inverted-vee
> > > with
> > > > 30 dB fades here in Tucson at 2225Z.
> > > > > I have no idea what it is.
> > > > >
> > > > > Wes  N7WS
> > > > >
> > > > >      On Monday, January 30, 2023 at 03:06:28 PM MST, David
> Eckhardt<
> > > > davearea51a at gmail.com>  wrote:
> > > > >
> > > > >  Strong here in N. Colorado.  7.195 MHz.  It is being heard at
> least
> > > > from E.
> > > > > Texas to Kansas and, of course, here in N. Colorado.  It is a clean
> > > > > unmodulated carrier and has been present for 3 to 4 days.  I've
> heard
> > > it
> > > > > typically during daytime hours, but not tried during the evening.
> > > > >
> > > > > Does anyone have information on what it may be?
> > > > >
> > > > > Dave - WØLEV
> > > > >
> > > > _______________________________________________
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> > > >
> > >
> >
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> > > >
> > >
> > >
> > > --
> > > *Dave - WØLEV*
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