15.370AM interfering with 20M in MN

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  • Updated 7 months ago
Is this possible or does it indicate an issue with my radio?
I have been plagued by a mystery noise on 20m.
After much patient 'hunting' I'm pretty sure it's associated with 15.370AM...Havanna Cuba. Their signal in MN in the morning is between 20 and 40 over.
I've noticed changes in the interference that aligned with changes on 15.370.
I'm a technology user not an engineer so I'll appreciate expert insights.
All the best.
Mike Webb
KC0YHM MN & FL
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Mike Webb KC0YHM

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Posted 7 months ago

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Ken - NM9P, Elmer

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I have posted about this station in the past.  At one point they were 20 KHz wide with audio that appeared to be a badly implemented digital audio, or perhaps poorly balanced digital amplifiers.

Their signal had very sharp transitions in the audio and was activating my WNB and NB and making my noise floor bounce and dance.  I couldn't run those settings very high at all before it wrecked them.

Be sure that your preamp is off when they are on the air, it will help a bit.  But when they are really strong, they make a mess of noise blankers.

Ken - NM9P
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Mike Webb KC0YHM

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Thanks Chris. I dont have any issues on 40 or 80 m.
Today was the aha day....I was able to verify that my noise was associated with the AM on 15mhz. I was also able to document that when radio havanna went away around 11am E... so did my noise.... So..do you believe the bpf represents the simplest solution?
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Chris Tate - N6WM, Elmer

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No problem. FWIW, Ken is right, the WNB will cause issues like this as well, but assuming you have it on for a reason.. if so I would try a bpf.  the preselectors in the newer radios could solve this as well.  the 6300 doesnt have preselectors making you susceptible to out of band qrm... US AM can also be a problem on 160m.
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Mike Webb KC0YHM

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Ken.. I would call it severe. I need to find a remedy if possible. I can only operate on 20m at this time and they are making it tough for me to keep my headset on! ;->
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Ken - NM9P, Elmer

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Try turning WNB completely off. Then add all the attenuation you have on the rig and see if the problem improves.

If not, check you coax connections and other antenna connections. You may have a loose connection that is rectifying their signal creating signal distortion inside your own system.

I remember about 4 years ago Tim telling of someone who had a bad lightning arrester that was causing all sorts of intermodal/overload type symptoms. Once it was replaced, things cleared up. (I think this may have been on a 160 inverted L and local AM stations were tearing him up.)

Le us know what you find.
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Mike Webb KC0YHM

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That is good information.
I'll ask my brother in law to do a connection check JIC....he can check the easy ones for me...I wont be able to do it personally for a few months...I operate remote 95% of the time. I live in Naples Fl in the winter and Bloomington MN in the summer...neither location allows towers and yagis so my station is built in rural Farmington MN...at a location I rent.
Thanks Ken