Hi Jaime
The only way to really improve signal to noise ratio is with directivity.
Better directivity better signal to noise ratio. Everything else is just
less deterioration or more deterioration. The only thing that makes a
difference is how narrow the front lobe really is.
Your 40m array plus the integration with your tower and inverted L is giving
you a better directivity. Probably if you try another direction the results
should be very different.
Things that people believe but does not impact signal to noise ratio.
1- Front back.
2- Noise canceling devices , (only help with weak signal it its narrow the
front lobe)
3- Vertical array, if you live downtown, or a city lot like mine, 150x 100
ft back yard. The manmade noise is only vertical polarized, vertical array
may help you to hear more noise.
If you want your vertical RX array to work, it is necessary to detune your
TX antenna, and any other vertical structure above 1/8 wave high, even it is
300 ft away. 160m one wave length is 480ft long, don't full yourself.
Get common mode out of your RX system input, good shield is a must, never
use plastic box for any RX system part. Open frame relay is also a big
problem, DC bringing noise to the amplifier, another thing. Choke and shield
is your friend, but only works with a good ground.
RDF measure directivity, more RDF better reception, but every single wire ,
cable, tower can deteriorate RDF, you need to control that.
You can hear my webinar at WWW.WWROF.ORG
>> https://wwrof.org/webinar-archive/n4is-waller-flag-construction/
>>
https://wwrof.org/webinar-archive/high-performance-rx-antennas-for-a-small-l
ot/
Just an update from that Webinar . NX4D using a Waller Flag from a 1/5 acre
lot is now at #311, confirmed on 160m.
My Horizontal Waller Flag, HWF, is working very well, I can hear 4K6FO , FR
, VU almost every time they are on the band.. I Heard 316 countries on 160m
since 2006, but the HWF was operational only after 2010. Now I am at #299
on 160m.
This is a thing people only believe when they see it happening. Almost 100
people is using WHF and VWF around the world, all of them delivering
excellent performance. However it is a huge project, not plug an play at
all, and it works!
73's
JC
N4IS
-----Original Message-----
From: Topband <topband-bounces@contesting.com> On Behalf Of Jamie WW3S
Sent: Wednesday, November 14, 2018 2:10 PM
To: topband <topband@contesting.com>
Subject: Topband: 40m array as RX antenna
I'm plagued with local noise, I live in a sub division, and have a small
loet (80x180), 2 yrs ago, I tried a reversible EWE and had pretty good
sucess with it, last year I tried a HI-Z 3L, and wasnt really any better
than the EWE. I put the EWE up again this season, and its so-so, but have
discovered that my 2 ele 40m phased verticals work great as a RC
antenna.....there is literraly no noise on this.....signal are weak, but as
this noise is S0, I can hear just about everything (OK I couldnt hear the FR
last night but I heard a bunch of EU calling him)......wondering why the
noise is so lowoh this array compared to my other antennas, and if thats a
clue as to what may be wrong (if anything) with the others.....my 160 inv l
is S9 noise level, and my EWE is about S3.....
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