[TowerTalk] Antenna modeling question

[StellarCAT]

John, Charlie,

My apologies! I had done quite a bit of modeling for my own situation and 
found that what seemed like ANY piece of metal of most any length coupled 
current in (and it does) and screwed with the pattern (doesn't necessarily) 
... I still find that for example if I want to use a 4 square (or 8 element 
which is what I'm planning on) anywhere near - (within 800') of a tower say 
on 80 meters I need to break the tower up twice to get the pattern back ... 
if used on 40, the rx array, I'd have to do even more gymnastics ... however 
I shouldn't have volunteered those results as being correct for Charlie's 
situation - I just modeled a 4 sq with 80' side spacing with 4 33' verticals 
in their 'center' ... there's no impact on 160 ... again my apologies. This 
result is using single ungrounded elements for reference.

Gary
K9RX



-----Original Message----- 
From: john at kk9a.com
Sent: Monday, September 5, 2016 9:22 PM
To: towertalk at contesting.com
Subject: Re: [TowerTalk] Antenna modeling question

Why would such short verticals effect the 160m RX array.

John KK9A


To: <n0tt1 at juno.com>, <TowerTalk at contesting.com>
Subject: Re: [TowerTalk] Antenna modeling question
From: "StellarCAT" <rxdesign at ssvecnet.com>
Date: Mon, 5 Sep 2016 07:51:34 -0400
List-post: <towertalk at contesting.com">mailto:towertalk at contesting.com>
the issue is more than likely not going to be 'what is the interaction of
the 160 on the 40 ... rather it is going to be what is the interaction of
the 40 on the 160 ... and my guess (after having played with a Hi-Z model of
their 4 element) it will be significant! The pattern will be quite
distorted. That I believe is easier to model as well - just leave the 4
internal verticals un-terminated. I'd love to hear the results.

Gary
K9RX



-----Original Message----- From: n0tt1 at juno.com
Sent: Sunday, September 4, 2016 11:50 PM
To: TowerTalk at contesting.com
Subject: [TowerTalk] Antenna modeling question

Gents,

I'd like to build a 40m phased array "inside" my 160m
receiving-only 9-circle and I want to check for any
interaction between the two antennas.

I have the layout in EZNEC 6, but I'm not sure how
to "feed" the 160m array.  Do I let it "float", ground the
elements or what?

Also, vice-versa...float the 7mhz array or....?

Suggestions?

Thanks,
Charlie, N0TT