Topband: Monopole Elev Pattern w.r.t. Earth Conductivity

[ZR]

The experience here during the stations contest days of the 90's was with a 
high inverted V at 160-180' (added 20' to the tower after a lightning hit) 
along with a pair of 1/4 wave verticals with 32 raised radials of somewhat 
random lengths in the 100-130' range running thru the woods. Those used 
simple CATV RG-11 coax phasing lines and relays to switch endfire directions 
or a broadside figure 8. Im still a big believer in KISS and not throwing 
money away at commercial solutions that offer little or no added benefit.

Single Op contest results were that the 160 part of the score was at the top 
of the pack or close to it and was also right up there with the MM stations.

My conclusion which also included pileup busting DX chasing was that the 
only improvement left to be gained was increasing the outpower from 1200W 
which was already around 3dB down from many and a lot more from several 
others. I still run the same 1200W amp.

Im 20-30 miles from salt water, on the top of a granite hill with very 
little soil but a killer take off angle. N6BV/1, who lived the next town 
over and Ive known since he started at National Radio fresh out of college, 
modeled it for a HFTA release which was part of the K6STI AO or YO package.

Ive also mentioned the "awesome" performance of an inverted V with the apex 
at 50' and ends at 3' when I first moved here. It was put up in a hurry to 
work one of the Antartic island DXpeditions and cracked one of the biggest 
pileps Ive ever heard on one call. Later at Dayton the op said I was at 
least 10dB above everyone and the only call he could copy. Bob Brown had 
used that to add to his ducting theories.

My own conclusions are that a low loss vertical and a horizontal of some 
modest XX height are needed if you want to be highly competitive. All this 
talk about what happens at 0-5 degrees or wherever is good to toss around 
but I doubt it has much to do about what really works for those of us not 
right at the salt water.

Carl
KM1H


----- Original Message ----- 
From: "Mike Armstrong" <armstrmj at aol.com>
To: "Tom W8JI" <w8ji at w8ji.com>
Cc: "Mike Waters" <mikewate at gmail.com>; "topband" <topband at contesting.com>
Sent: Wednesday, October 24, 2012 11:08 PM
Subject: Re: Topband: Monopole Elev Pattern w.r.t. Earth Conductivity


> Dang Tom..... I just sent out a more wordy version of what you just said. 
> This is getting strange.  Not sure why it hasn't been disseminated yet (my 
> email), but I swear I sent it just moments before  your email hit my 
> system.
>
> You just added some fuel to my fire.  Short version: I, with my rather 
> inexperienced eye (160 experience, that is) is seeing a pattern that seems 
> to indicate what we would call low radiation angles aren't really optimum 
> for long range 160 communications.  The other email goes into a little 
> more detail in why I am thinking this way.  Morning enhancement, 
> especially with high angle radiators (like mine) where I am working Japan 
> and Chile on a radiator that can very truthfully be called an NVIS 
> antenna.  On higher frequencies, a scaled version of my antenna wouldn't 
> radiate a signal out of the southwest region, much less thousands of miles 
> distant.
>
> Just a thought!  Again, my other email expounds a little more, but this 
> was the conclusion in a nutshell.  Maybe "low horizontal" antennas really 
> ARE better on 160 than they should be..... Given our experience with low 
> antennas on the higher bands, it seems counter-intuitive..... But there it 
> is.
>
> Mike AB7ZU
>
> Kuhi no ka lima, hele no ka maka
>
> On Oct 24, 2012, at 17:12, "Tom W8JI" <w8ji at w8ji.com> wrote:
>
>>> If we knew those, then we could calculate the location and distance of 
>>> the
>>> signal hops. That might give us some insight as to why some people have
>>> found a taller monopole to be worse than a shorter one at a given 
>>> distance.
>>
>> Back in the 70's or 80's there was speculation a low angle was lossy from 
>> grazing along, based on others having poor experiences with taller 
>> verticals. The top of my tall tower had some antennas and side arms which 
>> top loaded it a bit, but not much. Certainly the wave refracts gradually 
>> at a minimum, and so I think distance would not tell anyone much. There 
>> have been a host of theories since the 1960's, even some from Stew the 
>> real W1BB. :-)
>>
>> I don't know what happens when it gets up in the soup, although people 
>> like K9LA should be pretty well versed on it. I only know things behave 
>> differently all the time, and what antenna generally works most of the 
>> time.
>>
>> For example, at sunrise most of the time almost anything reasonably 
>> efficient works about the same here. It's more a matter of ERP at any 
>> not-too-low angle and any polarization.
>>
>> 73 Tom
>> _______________________________________________
>> Topband reflector - topband at contesting.com
> _______________________________________________
> Topband reflector - topband at contesting.com
>
>
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