Antenna Testing Event in Southern CA!

[Marconi]

Well MC what can I tell you? When I made that statement to whomever I thought it was the truth. I do not recall you ever saying what you are telling us here, but I could be wrong. I only recall that you gave us some of your ideas, but I did not know that you had decided on anything official as yet. I did say at some point that if I came out, I would of course follow whatever rules you guys came up with.

I have thought about it since I told you I would say no more and the only thing I did wrong was to talk about it after I said I would not. What I really meant to say was that I would not continue to bicker with you about our petty differences even if I had to stop posting anymore on WWRF. It would not be wise of me to have a running argument with the Administer for the antenna section, as it is my only real interest among all the topics. Just consider it a mistake on my part and that it was probably just some words in passing and that I should not have implicated you or your name in my remarks.

I have been working as much as I can on my little 1/4 wave antenna. As I made changes and it showed any improvement, I tended to talk about my work and progress to others a little. Maybe that was the mood that provoked me to say something about the Antenna Testing in the desert in May.

Just write down what you want me to say in retraction and send it to me. I will consider your request along with my promise not to say another word on WWRF.

 

[Master Chief]

Marconi, you are the MAN! I like you a lot! I have, even more, respect for you! I too love antennas!

I don't think we are bickering, I think "what we have here, is the failure to communicate." 8)

You have an open (unmoderated) forum here and anywhere else. I just want to make sure that I was not misunderstood about antenna heights! Look back to March 6th of THIS thread and you will see where I said.....

I really like the idea of the 60' to tip test! I wish I came up with that one!

We WILL do this test (although I have to figure out how to get the smaller antennas that high)!

I still wish we had more input from the group and a few RSVPs. If there is no interest, I see no reason to come from Texas, Nevada, or anywhere else, just for 2 or 3 people to play with antennas in the desert! I still need monitors on the receiving stations. I figured we could take turns!

I have no confirmation from Jay, Kale, Dan, or Wolf that they will even try to be there. I'll have a new I-10K and some old Avanti antennas, but that's it. If anyone else wants to throw an antenna in the test bed, you will have to pay to ship them here and back.

So, the clock is ticking and we have a "do or die" date of April 10th! Please everyone, let us know!

Marconi, if you want to come out anyway, we can still test antennas, but on a much smaller scale.

 

[Marconi]

Well I have scheduled some time for May 2-10. If that is the time, then I plan on being somewhere close by. I am completing my testing this week and if my results prove out I will bring my 1/4 wave, and I may bring a couple of others as well good Lord willing.

 

[Master Chief]

Great! I'm looking forward to it!

BTW, has anyone ever told you that a Starduster is not a ground plane, but actually a center fed 1/2 wave dipole? This is supported by the fact that the "ground radials" are brought down and actually adding to the vertical radiated signal. I've heard the argument and it has merit! If this is the case, they are no longer "ground radials", but the second half of a dipole.

Regular ground radials are perpendicular (horizontal) to the main radiator and do not add to the vertical radiated signal per se. They do affect it however.

Anyway, its an interesting argument that is sure to raise the hackles on some in here! :twisted:

 

[freecell]

the "radials" are the other half of the dipole regardless of their "angle" from the vertical element. all antennas are dipoles. if they weren't they wouldn't "radiate". the radials represent an artificial ground "above real ground" and as such their angle from the vertical element greatly affects the radiation resistance seen at the feedpoint. the starduster is still a ground plane antenna. that the radials are swept downward to facilitate increased radiation resistance to provide a better match to 50 ohm cable changes nothing.

as to the measurement height for testing, if angle of radiation at fixed heights above ground among the various antennas in "the field" is to be a comparison factor then all testing should be done at feedpoint height, not tip height. to test at tip height would provide a seemingly unfair advantage to smaller antennas and make takeoff angle comparisons between them unattainable.

 

[Master Chief]

the starduster is still a ground plane antenna. that the radials are swept downward to facilitate increased radiation resistance to provide a better match to 50 ohm cable changes nothing.

Yep, some say this also. Do you call it a ground plane because it has more than one radial? Is this antenna a ground plane?

as to the measurement height for testing, if angle of radiation at fixed heights above ground among the various antennas in "the field" is to be a comparison factor then all testing should be done at feedpoint height, not tip height. to test at tip height would provide a seemingly unfair advantage to smaller antennas and make takeoff angle comparisons between them unattainable.

Also a good point which plays right into Avanti's claim for the Astroplane. One constant would be the feedpoint height. This compares antennas apples to apples with relation to ground affect (which I will argue means very little with a ground plane antenna).

A SEPARATE constant would be the restrictions by the FCC to limit antenna height to 60'. If a Starduster or Astroplane gets out better than a Sigma 5/8 or Sigma IV, then we may prove what the Avanti enginners knew 30+ years ago.

Both are legitimate tests!

 

[mopar2ya]

I am going to give an opinion here that may or may not have already been mentioned. So please don't crucify me if it was.

The way I see it is that the average guy has a certain height tower he has access to, or pushup pole that he can guy to a certain safe height. If he could go any higher he certainly would. That being said, I think the test should be on the same test platform at a constant height. I think the test should just mount the antennas at the very top of that mast or tower with whatever mounting hardware that particular antenna came with. I don't think there should be any consideration for feedpoint height or tip height because the average guy isn't going to increase or decrease the height at which he mounts the antenna he buys depending on what it is. It will probably go to the very top of whatever he has to mount it to.

I think what I would do is test the antennas on a relatively low mast like 20 feet and take results to see which antennas will work better for guys that can't get 'em as high as we would all like to. Then go with the highest test mast you can muster for an all out performance test.

Just my 2 cents.

And by the way, thanks for even considering such a test for the benefit of all the forum members. I can’t wait to see the results.

 

[freecell]

"Yep, some say this also. Do you call it a ground plane because it has more than one radial? Is this antenna a ground plane?"

no, it isn't.

"A SEPARATE constant would be the restrictions by the FCC to limit antenna height to 60'."

while unfairly discriminating against the larger antennas. since in almost every case the feedpoint of the antennas in question is the point of origin for the generation of the electric field resulting from the opposing charges in both the vertical element and the radials, the larger antennas would be forced to operate at a lower feedpoint height, thereby diminishing the magnetic component in the far field (and associated signal strengths) when compared to their shorter counterparts. this is not what i would define as a fair and impartial comparison. on the other hand, if i wanted to promote physically smaller or shorter antennas, the imposition of the 60' limit would be the way to go to show them in a better light. forget the FCC regs (now you want to conform to them?) and keep the tests rooted in scientific principles or just forget them altogether.

if the tests are not performed with ALL ANTENNAS at the same feedpoint heights then ANY ATTEMPTED COMPARISONS of the results will be derogatory, meaningless and a total waste of time and effort. then there'll be plenty to argue about. for these reasons alone the feedpoint height rule deserves some serious consideration if you want to know how these antennas really fare against one another. i thought that was the original object of the exercise. correct me if i'm wrong here.

 

[RoadWarrior]

Not sure how the Top One gets out compared to the
orginal Astroplane. Having said that:
My I-10k beat the Top One, both 10ft off the ground
and 45ft to feedpoint (I-10K)--- 45ft to bottom ring
of Top One. It was over a 2 S-unit difference.
So, even raising Top One to a tip to tip test.
Not going change that much raising Top One 10 ft.
I also always called the Starduster a ground-plane.
I'll sit back here and keep reading the posts.

 

[freecell]

you reminded me of something else with your post RoadWarrior.

someone will want to make sure that if more than 1 listening post is going to be established that the S-Meters on ALL receiving equipment are calibrated to a single standard, for instance, 50uv. for S9. the standard itself is not as important as making sure that all receivers follow the same one. this is also important to the accuracy of the results. it's bad enough already that even in the most expensive of hf rigs that 1 S-Unit towards the bottom of the scale (below S9) can represent as little as 2.5db. instead of the more or less accepted standard of 6db. per S-Unit.

RW,

of course there's no way the I-10K produces 12 or more db. of gain over the Astroplane. that's not right. i hope you understand why.

 

[Master Chief]

Without going back an quoting everything freecell said, let me comment.....

I agree. Feedpoint height will be tested first. This has always been the plan as you can see from the beginning of this thread. Marconi had suggested the tip test and I think it is a good idea. That will be test #2. It has nothing to do with conforming to FCC rules, it has to do with Avanti's claims and design of an antenna and their associated claims. Besides, getting past 60' is harder to do (read: need bigger tower).

I've already talked to Justin about supplying calibrated radios (Uniden Grants) for two of the three listening stations. The third station will have a network analyzer or IFR. Again, this won't be scientific, but it will be consistant.

Maybe we should get away from the term "S-Unit" when talking about our on-air experiences using our high qulaity CBs and start using the term "S-Meter". This should eliminate the argument that an antenna has 3 or more DB of gain based on a crappy meter reading.

 

[RoadWarrior]

Yes, i know S-meters are not that accurate.
I was mainly testing to see which antenna heard people
the best and transmitted the best as i talk alot of local.
Out of all that i tested, i'm running the one that performed
the best and luckily it's also the best constructed antenna.
You guys have been kicking around alot of good ideas on how to test them in the desert.
Marconi and i'm sure others are curious about certain things.
While your out there testing, find the answers to any
questions you have.

 

[CDX-007]

Hey, this is coming together! - Glad I finally found this strand.

I know it's been this radio lover's dream since the 70's!

I have to agree about maintaining a standard mounting height, as in the real world I also believe the average guy (me) will get whatever antenna up as high as possible, so if an antenna design happens to have most of it's mass, and consequently, possibly it's point of radiation, lower than an antenna of a different omni design, I feel that is a built-in disadvantage of that design and should show up in the test.

Having stated that, I also like the idea of the tip-height test or 'THT' as any mounting height disadvantage would show up less if it were to be utilized in a hilltop application or other applications where the mounting height is a non-factor.

Now what I want to know is what have we so far for antennas to be tested?

I have a bone-stock Hy-Gain Penetrator 500 (except for the aluminum match which died in a move so I had to remake an identical one from C0PPER TUBING, but I noticed no difference in tuning or in performance before / after) which I can bring.

Will there be an opportunity for testing any modified designs?

What about a Sigma 5/8 or a Wilson Alpha V5/8? Anyone have one to bring / ship for the test?

Does anyone know if those two are different from one another in design?
I had a Wilson Alpha V5/8 back in '87 but it's long gone now, and I never broke it down to it's basic parts to determine if it differed from the Avanti Sigma 5/8.

I hope someone will have a Maco V5/8 as I doubt it will keep up with the full-sized 5/8, but I would like to test it as it seems to be the only IMAX 2000-priced 5/8 which is currently available on the market.
- IMAX 2000? - hopefully there will be one of those also.

I sure wish something like several ICOM IC-751(A)s would be used for the meter readings as they have one of the most linear meters and meter movements I've seen. The Kenwood TS-930 is a good one too.

I have to admit, the Yaesu 897(d) with the LDG aftermarket meter is quite impressive, but that little Grant meter might be too small to tell minor differences, plus I don't trust the AGC on those rigs - too non-linear.

Well I'm hoping to be there too.

Hey Stu / Phil, wanna car-pool?

_________________

BTW, a few weeks ago I successfully converted a Radio Shack .64 to a Penetrator 500 and am considering selling the kit.

I wonder if there would be much interest...?

73

 

[Marconi]

Well I am making plans for the first week in May 5-6-7 to be exact. If that is not it then I can't make it. Is the date settled?

 

[Master Chief]

DATE: MAY 5-7 2006

More details to follow this evening! Be prepared to B.Y.O.Everything! We will bring a BBQ so pack some meat! We will not be feeding you! I've considered a pot-luck, but with the lack of RSVPs thus-far, it would be risky to have one.

Call In frequencies:
CB = Channel 23
Ham= 145.520 simplex

We will camp in the desert! If you do not want to camp:

Budget Inn
11625 Lawson Ave
Adelanto, CA 92301
Phone: (760) 246-4077

Days Inn
11628 Bartlett Ave
Adelanto, CA 92301
Phone: (760) 246-8777

Bring motorcycles if you want to ride. Cars can make it across the dry lake with NO PROBLEMS!

Again, more details tonight!!!