Strange "backwards" pickup pattern

[deeciple]

Hi all,

I have been playing around with different antenna setups, trying to get the best signal possible and have done very well with the help of this forum (props to rabbit73).

I have a RCA mini Yagi (https://www.amazon.com/dp/B0024R4B5C/?coliid=I1BHHZ36CR4HE0&colid=273USBPISAEEA&psc=1&ref_=lv_ov_lig_dp_it) mounted in my attic with a Winegard LNA-100 (https://www.amazon.com/Winegard-LNA-100-Antenna-Amplifier-Booster/dp/B00BN5Z2UY/ref=sr_1_1_sspa?dchild=1&gclid=CjwKCAjwv_iEBhASEiwARoemvPQV5L3lU-NTiz_QVSNbzvTSkIJUuL7CZ31YsZ0nXDV1n-ct6dC6UBoCFHoQAvD_BwE&hvadid=190710895918&hvdev=c&hvlocphy=9009985&hvnetw=g&hvqmt=e&hvrand=7156416885902544484&hvtargid=kwd-300577858533&hydadcr=9738_9836272&keywords=lna-100&qid=1621010467&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExWkdFRUtGMkJQRVM0JmVuY3J5cHRlZElkPUEwNTc2MjI3MU1 QTjZMRDBJTkQ4VyZlbmNyeXB0ZWRBZElkPUEwMzE4NzMyMlREM1hGSFY0VEdDRiZ3aWRnZXROYW1lPXN wX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=) amp. I was getting great signal but lately I have noticed that the signal quality from WCNC and WSOC has weakened. While adjusting my antenna I discovered something strange. WCNC is roughly to the NW and WSOC is more to the north but if I move my antenna to the left (toward what would be WCNC) WSOC actually becomes stronger with better signal quality at the expense of WCNC. The opposite behavior is also true.

I find this to be very strange. My only guess is that it is attributed to multi-path propagation but that s just a guess. Does anyone have an idea what could be the cause of this bizarre behavior? I am considering this antenna (https://www.amazon.com/gp/product/B01MYMVPVX/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1) as it has gotten good reviews and with it's smaller size it would be easier to point. I have also read that it is more directional which I am hoping will help reduce any multi-path issues.

Here is my TV Fool report (http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d9038763bf86c44).

Any advice is appreciated.

Thanks,
Ken

UPDATE:

So upon further inspection, it seems that the TV Fool report has WSOC more to the west of WCNC, which is consistent with my pickup pattern. But the FCC map (https://www.fcc.gov/media/engineering/dtvmaps) and the RabbitEars (https://www.rabbitears.info/searchmap.php?request=result&study_id=261035) both have it the other way around. Which is right?

[OTAFAN]

Hi deeciple:

I would defer to RabbitEars as it is usually up to date, unlike the TV Fool report which, unfortunately has not kept up due to lack of/or very small staff.

Also, I think in a previous post rabbit73 suggested a window up in your attic if you can manage to put one in. That would not only let more light in but TV signal as well.

And the RCA751 you're using is a solid work horse that I've used here at my location, with excellent results in the past. But if you want to try the GE out, rabbit73 sure likes his and you can take that to the bank.

Just my two cents.....all the best.....

[deeciple]

Thank you OTAFAN. Good advice. I can't put a window in the attic but I remember reading that rabbit73 likes the GE Pro and cites it's excellent reflector. Agreed about the RCA. it has been great but it is also old and a bit beat up from being outside. Also, I don't believe it is really cut out for the conditions in my attic. I will post back with my results once I have tested the GE.

Best,
Ken

[Tower Guy]

I believe that the Rabbitears report is correct;
https://www.rabbitears.info/searchmap.php?request=result&study_id=262688

The odd situation that you describe is sometimes due to preamplifier overload. Try removing the amplifier (don't just unplug it) and run the test again.

[deeciple]

The odd situation that you describe is sometimes due to preamplifier overload. Try removing the amplifier (don't just unplug it) and run the test again.

Hmm. I hadn't thought of that. I will give that a try.

[deeciple]

...the RCA751 you're using is a solid work horse that I've used here at my location, with excellent results in the past. But if you want to try the GE out, rabbit73 sure likes his and you can take that to the bank.

The odd situation that you describe is sometimes due to preamplifier overload. Try removing the amplifier (don't just unplug it) and run the test again.

Hi OTAFAN and Tower Guy,

I tested out the GE Pro but it wasn't any improvement over the RCA (no worse either). I did manage to relocate the RCA in my attic to somewhere without any forward obstructions. I also added a 6db attenuator. It was a bit difficult to install it in the new spot but it did improve the stability of my signal quality. I am now dropout free and the "backwards pickup pattern" corrected itself as well.

Thanks for the great advice!

Ken