Topband: More anecdotal "stories" to cause one to stop and....

[Yuri Blanarovich]

Hi Mike,
As far as the ducting goes, here is some insight into the phenomena in 
my old CQ article:
http://k3bu.us/propagation.htm
160 exhibits peculiarities, depending on sunspot cycle, time of the 
year, solar activity.
There is polarization rolling around, angle fluctuation, spotlight 
focusing and one way propagation.
Effects can be quite pronounced and frequency sensitive. Wobbling 
between LW, MW and SW modes.
It is hard to tell at what time, what is happening "up there" to our 
signals. You could have experienced one thing, while others were "hit" 
by another. You just have to be there when "it" happens, especially when 
gunning for contest records.
When I had my stacked Razors and experimented with switching vertical 
angles I found that about 70% of time there was disagreement between RX 
and TX best angle/antenna. And I too experienced LDEs.
As far as your 5/8 vertical over salty "ground" I can see 1. super 
performance at low angles (in KH6 everything is long haul DX) and 2. for 
high angle lobe (unique property of producing "all polarizations") 
signals serving local area NVIS (KH6, boats etc.). Interference 
cancellation circles probably fall in "no man's" area, observed on VHF 
(repeaters).
After Team Vertical exploits with verticals on the beach, I explored 
Cape Hatteras, NC locations and was amazed too with some 10 -15 dB 
"gain" close to salt water, it was like driving into inside of the 
amplifier. 
Some "knowitalls" would ridicule other's findings, even managed to 
"correct" ON4UN's excellent book material.
73, Yuri, K3BU.us
www.MVmanor.com place for radiofest 

 
 
 On Mon, Sep 09, 2013 at 02:23 PM, Mike Armstrong wrote:
 
 > Same here, guys.  Please do reply here and if someone "already knows 
everything," they need not even read the thread, right?  LOL.  I have 
heard, but don't know if it is a common mode of propagation or if it is 
very rare, like LDEs on 15...... They do happen, but it is as rare as 
hen's teeth.  I have heard it 3 times on 15 that I am aware.... But I 
digress, the mode I am wondering about, and it might explain why even I 
with a low horizontal on 160 have worked some decent DX (Chile, Japan, 
several Carib countries, and some pacific islands)..... Is "ducting" a 
common propagation mode on 160?  If it is, that could explain ALOT when 
it comes to high angle radiators working DX that they probably shouldn't 
even hear with such a setup.
>
> Any thoughts from those who would like to talk about the subject of 
> high angle radiators (even NVIS), ducting and DX?  Quite honestly, 
> during one particular 160 contest a couple of years ago, I worked 11 
> countries (all new for me) all over the place except europe...... As 
> strange as it seems, those were the only countries that ANYONE in my 
> area was hearing or working.  So here I was working the same DX 
> stations that some guys with really decent 160 antennas were working, 
> but MY antenna was anything but ideal........ 300 foot long OCFD (fed 
> about 20 feet in from one side) and, this is the kicker, it is only up 
> 50 feet in the air on one side and 40 feet on the other side 
> (available trees, one of which is on my neighbor's property..... but 
> she is my mother in law, so no legal issues there.... lol).  So how is 
> it that I was working these stations with the same amount of effort as 
> the guys who had "ideal" antennas, like full sized 1/4 wave verticals 
> over an EXTENSIVE radial field.
>    It was a very pleasant surprise, but not expected at all.
>
> On later dates,I would hear people in the same areas of the world, but 
> no matter how hard I tried, not able to work them..... although I HEAR 
> them quite well on that antenna (it seems to be fairly low noise). 
> Something has to be "up," but I will be darned if I can figure it 
> out..... unless there is some prop mode that is common to 160  and 
> isn't on other bands where this type of antenna "scaled" in length and 
> height would suck 100 percent of the time...... LOL.  Well, maybe not 
> 100, but often enough that EVERY antenna book would say "get it higher 
> in the air....  ALOT higher"
>
> Thoughts from experienced 160 folk?  Again, only those interested in 
> talking about this subject need respond. :) :)
>
> Mike AB7ZU
>
> Kuhi no ka lima, hele no ka maka
>
> On Sep 9, 2013, at 8:56, Bill Cromwell  wrote:
>
>> On 09/09/2013 10:33 AM, James Rodenkirch wrote:
>>> ...think that there's "more to understanding" horizontal and 
>>> vertical antennas on Top Band.
>>> Listening to a fella on 80 SSB this morning about his experiences 
>>> with a vertical 1/4 wave and a horizontal loop on Top Band.
>>> He said he had both up and used them over a 20+ year period and 
>>> noticed that one would work better than the other for DX.  For five 
>>> years or so the loop would outperform, for a couple of years the two 
>>> would be equal and then for about five years the vertical would do 
>>> better.
>>> One can easily point to the 12 year period as aligned with the Solar 
>>> Cyclef BUT -- when I look at the radiation patterns for both I see 
>>> the loop as a hugely efficient NVIS antenna with little low angle 
>>> radiation.  Sooooo, I think there are some magnetic anomalies at 
>>> play here but -- if the radiation angles don't change, how does one 
>>> work "mo betta" than the other?
>>> I do have the ON4UN book and will start diving in to it more to see 
>>> if John can shed some light on this topic AND I don't wanna start a 
>>> cuss and discuss session here (I know many of you already understand 
>>> what influences the above "observations" so I don't want to rekindle 
>>> any previous "debates) but.....if someone can direct me to specific 
>>> sections of John's book or lother papers/websites, I would 
>>> appreciate it!!
>>> I consider myself a "newbie" re Top Band" propagation and "other 
>>> 'influencers'" on antenna performance (I do understand gray line, 
>>> the various ionized layers and all of that) but anxious to learn 
>>> more - thank you, in advance, for any "direction" you can point to 
>>> so I can learn.  Replies off line are probably mo betta - don't need 
>>> to get any pissin' contests agoin'!  Hi Hi
>>> 72, Jim Rodenkirch                       _________________
>> Please reply on the list. I'm interested, too. My own suspicion is 
>> there are parts of propagation that are not very well understood if 
>> at all and those bits are pointed out by what happens with real 
>> antennas as opposed to theoretical antennas. That does not dismiss 
>> the theories.
>>
>> I'm taking baby steps here and I am permanently limited by my postage 
>> stamp lot but we have all read testimony about success from small 
>> lots (and with low power). I'm cornering the parts to build a 'meter' 
>> that will give me information about the antennas I already have so 
>> that I might make them perform "mo bettah" - if I know whether to 
>> turn left or right when I get some 'numbers'.  Just like Jim, I am 
>> not interested in stirring up any pots. It's pretty easy with a 40 
>> meter dipole antenna to just go outside and cut off all the parts 
>> that don't work. 160 meters (or 600 meters) doesn't lend itself to 
>> that simplicity - if nothing else because of size.
>>
>> 73,
>>
>> Bill  KU8H
>> _________________
>> Topband Reflector
> _________________
> Topband Reflector
>