[TenTec] Radial Research

[Robert Mcgraw]

Dave I agree with your assessment.   As to the hype, I seem to think the
same logic about difficulty of using open wire/balanced feed system also
exists.

37
Bob, K4TAX

>
>
> I can't help myself. I've got to reply. Billy, everything that you point
> out is correct & is necessary to understand if one is to maximize his/her
> antenna system. However, you have ignored Rick's premise that I have left
> in his post at the end of this.
>
> The statement that Rudi's work is excellent should not be ignored. Rick
> further points out that he is addressing the ham with little real estate,
> etc. Qui te frankly, for many of us, this is a hobby, not an avocation.
> We are fully capable of understanding most of what Rudi has written. True
> engineering & design of antenna systems (or anything else) is the
> application of the learned facts (not ham lore) in a given situation.
> That includes QTH, time available, desire to expend countless hours
> measuring & pruning, etc.
>
> I would love to be a big gun with multiple rotating towers & stacks of
> beams. That has not, & will not, happen. I'm on 1.6 acres. I have done a
> lot with Rx loops & am looking at a 4-square solution. However, There is
> no way, based on the layout of the property, that I can string all of the
> radials that I would need to improve my system. I can tell you that in my
> situation, based on actual trials, my 1/ 4 wave 80 M vert & my 160 M Tee,
> each with 2 raised 1/4 wavelength long radials & both fed with Davi s
> Bury-Flex perform better than did my 300+ ft dipole at 65 or 80 feet
> (I've got some really tall trees). Yes, I did a lot of calculations &
> measurements & adjustments to get it where it is now. By perform better,
> I mean that I am now working more DX and have added to my DXCC total.
> That's my goal, not building an antenna that is a few db hotter at the
> expense of lots of $ & time that can be better spent (for me) by
> operating.
>
> One of my fears (based on some of my early ham experiences) is that the
> ham who is new to all of this will be turned off by all of the 'hype'
> that you cannot have a working vertical antenna unless you have 40 to 160
> radials & spend endless hours pruning it. Yes, it would be better, but 40
> years ago, I did not experiment with verticals largely because all of the
> technical data showed that it would be too complex for me to handle. Then
> I read a book by W6SAI ( Bill Orr, SK). He knew more than I ever will,
> but he presented it to the layman. He also made clear that it was OK to
> try things that didn't work as well as those built by some of the
> 'experts'. While I'm sure that it is not your intent, I fear that we may
> turn off some of our new hams with our insistence that anything but
> perfection is unacceptable.
>
> Thanks for the bandwidth to rant. There's no disrespect intended in
> anything I've written
>
> 73
>
> Dave
>
> WA3F
>
>
>
>
>
> ----- Original Message -----
>
>
> From: "Billy Cox" <aa4nu at ix.netcom.com>
> To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
> Sent: Saturday, May 19, 2012 7:35:02 AM
> Subject: Re: [TenTec] Radial Research
>
> Once again, I would suggest that we are tossing out
> "ham lore" without an accurate basis of support, see
> below please and let's walk through your statements
> together here.
>
> Rick, I tend to agree with most of your posts over
> the years, but am going pushing back on some statements
> made in this post, not on a personal basis, rather with
> a trend in our hobby for sadly what seems to be a loss
> of technical accuracy, my reply is simply an attempt to
> change the tide and help others to better understand
> HOW all this really works.
>
> OK, can we agree on that focus please? I hope so.
>
> Certainly each of us makes do with the best we can,
> however to make broad statements without any real
> technical support is at best misleading, and worst
> are outright falsehoods to those who are interested.
>
> There are solid technical reasons the majority of
> broadcast stations have not abandoned their ground
> radial systems in favor of elevated radials.
>
> So let's look at what we DO agree on first.
>
> Do elevated radials systems "work"? Yes.
>
> Are they "better" than no antenna? Yes.
>
> How "well" do they really work in most cases?
>
> Here I am afraid we may be on different walks
> in the land of RF. Why would our answers vary?
>
> No one knows UNLESS they do their diligence!
>
> N6LF did such, and then some decided to make
> their up their own skewed conclusions, which
> then lead to his follow-up letter saying WHOA,
> it's not that easy to replicate 100% acceptable
> results, especially with only 4 elevated radials
>
> QSL so far?
>
> Now how many are going to PROPERLY replicate his
> effort needed for 10-12 elevated radials? And
> what did he say, and then restate about simple
> systems or systems built without measurements?
>
> Despite inaccurate postings, there is still no free
> lunch as to our antennas and how they work best.
>
> For someone to read a posting that says elevated
> radials are THE WAY to go and then run and do their
> best to just build such in their backyard thinking
> WOW I will have low losses, this is really going to
> be better than jelly on a hot biscuit ... and then
> they wonder why it does not play as expected?
>
> Such is sad, because the RF devil is in the details!
>
> And shame on us for not accurately sharing what is
> going to be required for such performance. I am
> not speaking of trying to find the last tenth of a
> dB, rather the dBs of loss for not understanding
> what is required for the system to work properly.
>
> A radial being at resonance as a sign of efficiency
> is not correct. My dummy load also appears to have
> resonance, but that unit is a very very poor antenna!
>
> The statement was made saying, "Considering that,
> when someone says if I don't get it perfect, I will
> have 2 to 3 dB pattern distortion and 1 to 2 dB of
> additional loss. hey, let's get real."
>
> Hey, I agree, let's get real. You just posted what
> I label "ham lore". You and I really DO NOT know
> that the loss for WX0ABC in his back yard will only
> be the numbers you tossed out, do we? No, we do not.
>
> Due to houses, trees, other wire antennas, towers,
> power lines, etc. ... it could just as well be stated
> as 20 to 30 dB pattern distortion and 10 to 20 dB
> of additional loss. We can't promise WX0ABC that if
> he or she does what we do, it will play 100% exactly
> as what we might have done in our 100 acre field
> with no objects to cause losses in the pattern.
>
> Or what if WX0ABC lives on a lot where he can hear
> and see the ocean's waves because he is that close
> to the salt water and his back yard verses the little
> dirt and much rock here at my Tennessee QTH?
>
> Could we agree that the same exact 'system' installed
> at WX0ABC's beach front property is NOT going to
> perform the same as it would in my backyard here,
> or at your side of hill location there in Germany?
>
> Why, because there are fundamental differences that
> cannot be ignored, but many want to overlook such.
>
> Posts suggesting exactly that are made frequently
> despite what the data, go re-read N6LF's details, is
> actually telling us to be aware of the losses when
> we don't carefully replicate and measure the results.
>
> His website contains some excellent real world
> data, especially as to tower interactions and
> verticals, all very good material to review.
>
> Honestly Rick, how much real time do you have using
> both ground mounted and elevated radial systems
> to support your statements? I have used the various
> configurations with my 4x arrays for years and it
> NOT quite as easy or simple as you infer here.
>
> Low SWR on the main feedline is NO indication that
> the vertical antenna array is working as it should
> and I have the burned up parts to prove this point!
>
> Arrays tend to multiply the real losses of any single
> vertical, so the comparison holds very true here.
>
> Again, having "pattern" or Front to Back, is NOT an
> indication that an antenna is not really lossy.
>
> How about another real world example?
>
> OK, RX antennas, consider the Beverage as an example,
> we don't use them for TX do we? Why? Because of their
> overall losses, so no, we don't even consider such.
>
> So let's narrow the focus here and look closer at
> this statement:
>
>>It is fundamental to understand that a good working
>>vertical on the low bands is typically 2 to 3 S-Units
>>stronger at a distance DX station than your 40' high
>>horizontal dipole. Â *** This is 12 to 18 dB improvement.***
>
> Really? That's "ham lore"! Again let's dig into
> the details that might support such a statement.
>
> 1. What's is your definition of a "good working vertical"
> my friend? That's not going to be the typical 4 stray
> elevated radials, hung willy nilly in the yard and without
> proper feedline isolation and no idea of what the currents
> are as to being balanced.
>
> This means most setups are really "the luck of the draw",
> are not repeatable and flunk the first part of your statement.
> They in reality are NOT "good working verticals". Which is
> also exactly the caution stated and re-stated by N6LF.
>
> Somehow, perhaps due to "ham lore", the take away has
> become "few elevated radials = GREAT performance. That
> is NOT a true statement, without proper qualifications.
>
> OK, let's move on ... as I am still looking for this
> 12 of 18 dB of improvement? But I have not found it yet.
>
> 2. Which low band are you speaking of here for the "12 to 18
> dB" improvement using a 40' dipole? Trying to make such a
> broad statement, without qualification is wrong and a distortion,
> as 40m (with a dipole at 40') performance and 160m with the
> same height and dipole are NOT going to be the same.
>
> Again, "ham lore" begins with statements without accurate
> qualification and then it gets repeated and accepted as
> being 100% truthful. So I disagree with your statement.
>
> Why?
>
> A. Even a low dipole may have 6 to 8 dB of ground reflection
> gain, that the vertical will not, be it 10m or on 160m.
>
> B. You are UNDER-estimating the ground losses here and in
> reality, again go back and re-read what N6LF discovered
> and posted in his text and graphs. Where is this 12 to
> 18 dB GAIN you are claiming? It is simply not there.
>
> What is the gain of a perfect vertical on a perfect ground
> with no losses?
>
> 0.0 dBi
>
> What is the gain of a perfect dipole on a perfect ground
> with no losses?
>
> 2.1 dBi is an accepted value, the "i" = "isotropic"
>
> So in a perfect backyard world ...
>
> Allowing 2.1 for gain over isotropic, and 6 - 8 dB for the
> ground reflection, that puts the net at 8.1 to 10.1 dBi
> in favor of the dipole, not + 12-18 dBi for the vertical.
>
> C. If you want to consider another idea for a ground system
> with possibly less loss, then see an excellent recent work
> by K2AV as published in the most recent NCJ for details and
> note the actual measured losses of most vertical systems.
>
> www.w0uce.net/FCP_Facts.pdf
>
> D. Which leads to another point, when the typical ham uses
> a "trap" or less than full sized vertical, which is common,
> then you have even MORE losses, both in the antenna and
> for the same stated ground system, again the 12-18 dB gain
> statement drifts more and more into fiction and a dream.
>
> We, with diligence can overcome some of this additional
> LOSS, but once again, first we have accurately understand
> what/where/why the LOSS occurs.
>
> Sadly, that's not what happens is it? A post is made on
> a forum, and Joe or Jane, the new ham reads it, and they
> go and invest limited resources and try and build up a
> new antenna, and then the expected performance is NOT there.
>
> Pop quiz? How many can complete this statement: Ready?
>
> "Verticals radiate equally ........ in all directions.
>
> OK, quick show of hands if you used the word "poorly"
> as the missing word in the above sentence? I thought so.
>
> Not an accurate statement, without qualification is it?
>
> Yet, "ham lore" continues to repeat it year after year.
>
> Why? Because we don't hit the PAUSE button and take a
> moment or two, and ask "is that really true?"
>
> Here's what I suggest you replace that above sentence
> with and repeat it over and over in the right context.
>
> "Verticals, like any antenna, with the proper design
> and attention to details such as loss, work well!"
>
> I did not say 12 - 18 dB stronger.
> I did not say 1st one to break the pileup.
> I did not say always is the very best antenna.
>
> "Verticals, like any antenna, with the proper design
> and attention to details such as loss, work well!"
>
> Now, I understand the point you were trying to make as to
> the lower wave angle of a vertical verses the higher wave
> angle of the lower horizontal, but you can't claim what is
> theory as an advantage and then ignore the real world of
> where the respective lobe peaks and nulls occur.
>
> Example? Let's say at 10 degrees wave angle, the vertical's
> main lobe is 12 dB stronger on 160m than the main lobe of
> the 40' high 160m dipole, which would be at 90 degrees or
> directly up. Sounds great right?
>
> WRONG as Jim, K9YC would say, why? Because your 4 elevated
> radials and a short vertical, as most of us are not going to
> be able to install a 130' tall vertical, may really have a
> real world LOSS of 12 - 18 dB ... NOT an improvement!
>
> We have losses due to the short vertical
> We have losses due to less than perfect grounding
> We have losses due to less than perfect feedpoint matching.
>
> BTW, read and re-read Jim's work in this area as to
> the proper use of baluns for feedpoints.
>
> So then what's the net net overall gain or loss here now?
>
> Aha, well, we don't know unless we accurately measure it!
>
> It might be a break even, or the dipole might be better
> due to the total losses of the 4 elevated radials and
> a base loaded 45' vertical. That's the world we live in
> and it's not one with an extra 12-18 dB of improvement
> just because someone says so on an Internet forum.
>
> In the real world, when you consider the total losses
> for each piece of the system, 12-18 dB loss may really
> be closer to an accurate figure once it is measured.
>
> That's what several, including K2AV have found as truth.
>
> Real world, despite years of effort with my low band
> arrays, for say 80m, a simple dipole at 130' is going to
> be stronger for a given situation, say from TN to your
> Germany QTH there, than my 4x even if I was able to reduce
> my total ground losses to NIL.
>
> Why? The best gain of the 4x array will be 4.5-5.5 dBI
> while the 130' high 80m dipole, due to ground reflection,
> at say 30 degree wave angle is going to be roughly 2 to
> 3 dBi stronger than the much more complex array.
>
> If I am trying to work someone in the NULL of the 4
> main lobes, say 90 degrees to Africa, then that same
> high dipole is going to 'appear' even stronger?
>
> Now when that same dipole, positioned to be strongest
> into Germany is used to try and work the JT1 on 80m
> CW, which is in-line with my NW pattern, and in a null
> on the 130' dipole. The dipole may never hear the JT1
> because the dipole has a NULL on the JT1's heading.
>
> Such is the life of antennas and sometimes being simple
> is still the 'best' route to take. Sometimes it is not.
>
> Again, I repeat, there is NO FREE lunch with the total
> system performance. Losses have to properly addressed
> otherwise we are all writing fictional stories. hihi.
>
> That's why N6LF has continued to experiment and provide
> additional information as to what one has to do in order
> to achieve the level of performance some say is so easy.
>
> So do we agree, each of us needs to decide what is "best"
> for our individual situations. Total agreement here.
>
> However, to make postings claiming 12-18 db GAIN or that
> elevated radials are "best" is a distortion of technical
> truths and may cause others to incorrectly understand how
> our antenna SYSTEMS really work with each QSO we make.
>
> Here's to ALL of us being open to learning new facts about
> how our antennas really work, what impact that, and things
> maybe can be made better by taking the time to read and
> understand what goes on out of sight in the backyard or up
> on the rooftops at our homes.
>
> One of my favorite quotes about this mysterious thing
> called radio and how it works is this:
>
> ""Albert Einstein, when asked to describe radio, replied:
> "You see, wire telegraph is a kind of a very, very long
> cat. You pull his tail in New York and his head is meowing
> in Los Angeles. Do you understand this? And radio operates
> exactly the same way: you send signals here, they receive
> them there. The only difference is that there is no cat.""
>
> http://www.sonic.net/~gralsto/einstein/quotes.html
>
> Have a great weekend!
>
> 73 de Billy, AA4NU ... who is still learning too ...
>
> -----Original Message-----
>>From: Rick - DJ0IP / NJ0IP
>>Sent: May 19, 2012 8:48 AM
>>To: 'Discussion of Ten-Tec Equipment'
>>Subject: Re: [TenTec] Radial Research
>>
>>REALITY: Â We all should strive to make our antennas as efficient as
>> possible
>>and Rudi's work is an excellent guide, but even if you can't build
>> anything
>>remotely close to what he describes, Â EVERYONE with just a little bit
>> of
>>real-estate can build themselves a great vertical antenna with a lot
>> less
>>effort than Rudi described.
>>
>>I would remind you of the THREE reasons for using a vertical antenna in
>> the
>>first place:
>>
>>1.        Because you have to; no space for a low band
>> horizontal dipole
>>2.        Because you want to improve your ability to work low
>> band DX
>>3.        NEW:  Your sea container with all of your equipment
>> and antennas got
>>lost in transit on its way to some distant island (see T32C DXpedition
>> to
>>Christmas Island - www.tt2c.com ), so you organize a bunch of
>> telescoping
>>fiberglass poles and some wire and build your vertical antennas on-site.
>>
>>Let's focus on #2 because this would be the case where we have time and
>>space to apply what we've learned from Rudi.
>>
>>
>>73
>>Rick, DJ0IP
>>
>>
>>
>>
>>_______________________________________________
>>TenTec mailing list
>>TenTec at contesting.com
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