Topband: 4sq vs SAL 30 Mkii in a forest

Mon Feb 18 23:58:58 EST 2019

I have  had both.
First, the SAL-30 is currently being used at my station and hears considerably better than my 160 vertical.  It exhibits F/B somewhere around 15-20 dBs on 160.  It is located about 100 ft from the nearest antenna (the westernmost vertical of my 4 sq for 80), about 150 feet from my tower and 175 ft from my 160 vertical.  Other than that it is in the clear...no trees at all.  I am totally satisfied with its performance.  It hears about the same as my 4 sq for 80, and down from my 4 el at 85 ft for 40.  Although sometimes it does hear better on 40 and 80, but not often.
In FL I had a Hi-Z array but I always felt it was compromised.  Why?  It was in the back part of my lot where several elements were very close to the trees.  One element was almost touching the trees...big oaks with lots of Spanish moss.  I also had a run of TV cable of 550 ft to it.  This is not to bad mouth the antenna system, I just felt I had put it in the wrong part of the yard and it might have performed better with less of a run and further away from the trees.
I sold the station about a year after I bought the antenna so I never moved the system.
By the way, 160 was hopping over the weekend out here in the ARRLDX....331 stations and many were VERY LOUD.
Bill K4XS/KH7B/KH7XS

-----Original Message-----
From: Lee STRAHAN <k7tjr at msn.com>
To: Joe Subich, W4TV <lists at subich.com>; topband at contesting.com <topband at contesting.com>
Sent: Tue, Feb 19, 2019 4:15 am
Subject: Re: Topband: 4sq vs SAL 30 Mkii in a forest

  Joe and all,
  Looking at the YCCC plots show all back lobes on 160 meters to be right at 20 dB down. The Hi-Z 4-square as shipped has only 2 side lobes and both are at 20 dB down with a notch directly off the back at usual 30+ dB down. Its true there are plots around that show the -13 dB side lobes on the 4-square which is a special phase delay to maximize the RDF another 0.1 dB or so.
  In addition, the 4-square suffers NO degradation in pattern and produces the same F/B and RDF on 80 meters as it does on 160. The YCCC is degraded on 80m. If the 4-square is built on a 60 foot side dimension instead of the usual 80 feet there is less than 1/10 reduction in RDF on 160 and the nearly same 160 meter performance is also available on 40 meters as well.
    There is one fact that remains. Having any receiving antenna that works is always better than none at all. Compromised or not. The only indicator of performance in the long run is smiles behind the dial. Hope you, K7XH get lots of private messages to help you with your choice as well. I am thinking your trees are a non-issue.

Lee  K7TJR
Hi-Z Antennas

 > Any experience with the same or  thoughts?

I would recommend looking into the YCCC "9 circle" (or "5 square") array.  Even though the kits are no longer available boards appear to be available from the PI4CC group.

The vertical arrays are less susceptible to wildlife damage than the SAL (due to the low horizontal wire of the SAL) and provide a higher signal level (before the preamp).

I like the YCCC design because it has a cleaner pattern than the
4 square (the center element is not "split" and thus does not cause a spurious sidelobe response).  Further, the "9 circle"
version provides 45 degree pattern selection (vs. 90 degrees for the 4 square) and if 90 degree steps are acceptable, the 5 square version provides the higher RDF in the same space (60' diagonal square).

As long as you keep the verticals (or the ends of the SAL) 10 - 15'
or so from tree trunks and keep the "brush' out of the array any degradation should be minimal (mostly as additional losses) with any of the antenna designs.

If you are comfortable with NEC (antenna modelling), I urge you to run the models of all three designs and make your own choice.  Based on the models, the SAL appear to be "unstable" and more prone to environmental factors that the "amplified" vertical arrays.

73,

    ... Joe, W4TV

On 2019-02-18 2:56 PM, Mike Fischer wrote:
> Hi all, newb to the topband 160 reflector here so thank you for any 
> coaching or corrections on protocol…
> 
> I live on a heavily forested (douglas firs - almost all of which are 100’+) piece of land.
> 
> I have enough room left to put up either an SAL 30 or a  4sq of 20’ 
> verts with 80’ spacing. HiZ probably
> 
> Problem is regardless of which I choose, there will be at least one or two trees in the “infield“ and foliage around the edges.
> 
> Any experience with the same or  thoughts? Grateful for the coaching 
> please feel free to reply direct to  mikebfischer at comcast.net
> 
> 73
> K7XH
> 

_________________
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
_________________
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector