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eHam Forums => Antennas and Towers and more => Topic started by: NN2X on February 13, 2011, 04:55:29 AM



Title: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: NN2X on February 13, 2011, 04:55:29 AM
I am one person who likes to verify claims of manufactures, years ago, I put up an Quad system (Lightning Bolt)(15 Meters on a 24 FT Boom), and HyGAIN Mono Bander with similar boom length, and work the world..That was really interesting fact finding results..The Quad won, but not as much as you would think...However, in a Multiband configuration, the Quad eliminated any multiband system

Now how about this HEX Beam, Here is what manufactures claimed, all you need is 30 to 35 ft, and this match any 3 element mono bander even if it is 10 ft or 20 ft higher..Believe me, I called them all and they all same the same thing Now, Mosley claims they have a 3 Element Yagi that can achieve more then 8dB above a dipole while only using 3 Elements on a 24 foot boom..

OK, I believe them both..So this means, if I were to have a HEX Beam at 30 FT, and compared with a 3 Element 10 ft higher we should get the same results..

Well, I purchased a Hex Beam, they are all fairly the same, some might be more mechanical, the other may have 1 db more forward gain, all in all, fairly the same design

I also I went ahead, and ordered a Mosley, 20 Meter / 24 Foot boom 3 element yagi..(Mono Bander)...

I will put the Mosley at 40 FT, and the HEX Beam is already at nearly 30 FT…OK, Lets see…I will be on the air for all to compare, for at least 3 months…I love doing stuff like this…Again, I could care less who wins, I just purchased both of them,..

Remember, I am only taking the claim from both manufactures, nothing more..Hex beam only needs 30 ft, and can beat out or equal a 3 Element Yagi that is 10 ft higher..So I am taking this test on, by putting my own money on this comparison …

 
I will start these A B Tests around March 15.



Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: WA8UEG on February 13, 2011, 05:51:08 AM
I agree, should be interesting. I would love to set a sked when you have it set up and ready to compare. My experiance with quads was the same, I compared my 2 ele 20/10 quad (Hy Gain Hy Quad) to my TA33 both at 45 ft and the quad blew it away in every aspect from gain to F/B ratio. Many will claim that a 2 ele quad has no advantage over a 3 ele. beam but sure isn't true at my qth.


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: K0OD on February 13, 2011, 07:26:17 AM
Excuse me but I'm having a hard time reconciling your post today with your post yesterday when you weren't even sure what 20 meter monobanders were made by Mosley (or Mosely as you called it yesterday).
http://www.eham.net/ehamforum/smf/index.php/topic,73407.0.html

I hope your costly test is conducted with engineering precision not evidenced in your prose. For the experiment to have any validity, those large antennas will have to be separated by a few hundred feet and be over flat land. Two proximate yagis will interact.  The test won't be valid if either antenna is over, or even near homes, power lines etc. Your home in Allen Texas doesn't seem to have the required lot size.

--
NN2X said : "I will start these A B Tests around March 15"

I doubt you'll get the Mosley yagi that soon. Did you ask about delivery time, as several suggested yesterday (and how did you order on a weekend?)
 


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: KH6AQ on February 13, 2011, 07:44:51 AM
A-B testing is best conducted on received signals. Rapidly switch A-B. There is no need to do transmit testing. 100 receive comparisons can be conducted in a couple of hours. I find it best to test on different paths and different days.

Note that because they are logarithmic units decibels and S-units cannot be averaged. They must first be converted to linear units (volts), averaged, and converted back to logarithmic units. Plotting the data can be more revealing than simply stating a number.

BTW, your test will be more of a height test than an antenna test per se. The difference in gain between 30 feet and 40 feet should exceed the gain difference between the two antennas. The test results will be confounded by the height difference and a claim that antenna A is better than antenna B will be suspect.

What will the results be? The monobander at 40 feet will beat the HEX beam at 30 feet. In fact, since this is a known, and can be modeled with NEC, there is little point in installing and comparing the two antennas.


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: WB2WIK on February 13, 2011, 08:59:48 AM
Hex beams are shortened 2L yagis.

A 3L yagi on a substantially longer boom should blow it away.

Test finished. :D


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: NN2X on February 13, 2011, 09:20:50 AM
This is for K0OD..

Did you wake up on the wrong side of the bed? So what I misspelled the Mosley, I was on my IPAD, did not know I was interviewing to write a book or a spelling contest.....I can tell you that Mosley doesn’t mind, especially when I bought their antenna. (CL 203)…

This supposed to be fun Hobby. I am just comparing two antennas that is all

Yes, I purchased the antenna from Mosley yesterday, from Gary…If you want to check, go for it…(My call NN2X)

While you are at it, check with HEX (Bobber) I purchased the HEX Beam from him. Anything else that you need to verify?

About delivery, Mosley, indicated in three weeks, (First week in March)…

But please get off my back with the spell check, go and chase some DX or something

Best

Tom Wright

NN2X.



Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: WB4AUW on February 13, 2011, 09:55:40 AM
I agree with WB2WIK. I've never talked to any of the Hex Beam manufacturers but I've never seen claims in their ads to beat a mono-bander in any circumstance. The claims I've seen say that they work well at lower heights.


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: W7ETA on February 13, 2011, 01:52:50 PM
Best of luck OM with your experiment.  I hope you have a lot of FUN while playing around with those two antennas.

Rest assured, when you post the results they won't be perfect, at least to the point that some people will complain about your set up and your observations.

Best from Tucson
Bob


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: WA8UEG on February 13, 2011, 02:06:02 PM
Hex beams are shortened 2L yagis.

A 3L yagi on a substantially longer boom should blow it away.

Test finished. :D

Oh Yea, count on it. Like compairing Randy Johnson's fastball to mine. 


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: WB2WIK on February 13, 2011, 02:32:55 PM
Hex beams are shortened 2L yagis.

A 3L yagi on a substantially longer boom should blow it away.

Test finished. :D

Oh Yea, count on it. Like compairing Randy Johnson's fastball to mine. 

I heard your fastball is pretty good.



Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: WA8UEG on February 13, 2011, 02:51:36 PM
A-B testing is best conducted on received signals. Rapidly switch A-B. There is no need to do transmit testing. 100 receive comparisons can be conducted in a couple of hours. I find it best to test on different paths and different days.

Note that because they are logarithmic units decibels and S-units cannot be averaged. They must first be converted to linear units (volts), averaged, and converted back to logarithmic units. Plotting the data can be more revealing than simply stating a number.

BTW, your test will be more of a height test than an antenna test per se. The difference in gain between 30 feet and 40 feet should exceed the gain difference between the two antennas. The test results will be confounded by the height difference and a claim that antenna A is better than antenna B will be suspect.

What will the results be? The monobander at 40 feet will beat the HEX beam at 30 feet. In fact, since this is a known, and can be modeled with NEC, there is little point in installing and comparing the two antennas.

Yea, but if your going to get a Mono bander anyway and have the facility to have both of them up why not? I would/did when I installed my quad a couple of years ago and my TA33 was still up. I was amazed at how much better the quad was on F/B ratio then the TA33 and how much more directive it was. After "testing" for a few days the TA33 came down and went on QRZ for sale, sold it in 5 hours!! I wasn't trying to do a paper or write an article on which was best just wanted to compare while I had the chance to do so. I think that is what he is looking to do and I am sure willing to listen and give some on air results as well.


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: G3TXQ on February 13, 2011, 03:16:30 PM
Now how about this HEX Beam, Here is what manufactures claimed, all you need is 30 to 35 ft, and this match any 3 element mono bander even if it is 10 ft or 20 ft higher..Believe me, I called them all and they all same the same thing

Can you confirm that you were told that by ALL the hexbeam manufacturers? Apart from Mike Traffie, I know the others fairly well and am surprised you were given that information.

K4KIO claims about 3.4dBd Gain for his hexbeam on his web site
DX Engineering claim "approximately 3dBd Gain"
MW0JZE claims 3.8dBd peak Gain

Could you tell us who you spoke to from these manufacturers that told you a hexbeam at 30ft to 35ft would match any 3 element monobander 10ft to 20ft higher?

Steve G3TXQ


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: G3TXQ on February 13, 2011, 03:21:38 PM
Now how about this HEX Beam, Here is what manufactures claimed, all you need is 30 to 35 ft, and this match any 3 element mono bander even if it is 10 ft or 20 ft higher..Believe me, I called them all and they all same the same thing

Can you confirm that you were told that by ALL the hexbeam manufacturers? Apart from Mike Traffie, I know the others fairly well and am surprised you were given that information.

K4KIO claims about 3.4dBd Gain for his hexbeam on his web site
DX Engineering claim "approximately 3dBd Gain"
MW0JZE claims 3.8dBd peak Gain

Could you tell us who you spoke to from these manufacturers that told you a hexbeam at 30ft to 35ft would match any 3 element monobander 10ft to 20ft higher?

I carried out extensive A/B comparisons on 20m between my hexbeam and a reference dipole at the same height. After 1500 comparisons I was able to say with 80% confidence that the hexbeam gain lay between 3dBd and 4dBd.

Steve G3TXQ


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: K0OD on February 13, 2011, 04:15:31 PM
Quote
"I carried out extensive A/B comparisons on 20m between my hexbeam and a reference dipole at the same height. After 1500 comparisons I was able to say with 80% confidence that the hexbeam gain lay between 3dBd and 4dBd."

Hey Steve, hope you're not going to interject any of your engineering mumbo jumbo into this.  ;D

What comes next, page after page of charts?
http://www.karinya.net/g3txq/hexbeam/measurements_2/




Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: NN2X on February 14, 2011, 06:21:03 AM
I am only sharing my testing experience, and people get testy when the possibility the sales pitch can be quantified in a small and modest tests, and yes mine are meaningless, worthless, unless you are me testing at my location, it means something!

Anyway, in the name of fun...I will perform the test…

But imagine, if for example, the HEX Beam is only one S Unit less, (Which every one says in 6DB,)..we can indicate that the costs of HEX Beam set up versus the Mosley antenna (Mono Bander) per S Units

For Example…

Lets say, the Mosley set up costs, about 2500 to set up, the tower, Install and antenna, while the HEX, beam, costs about 500 (USD) mono Bander (Bobber HEX Beam)..(I am using a push mast), I can put up the antenna by the way, up to 35 ft, temporarily and so therefore the height will be only 5 ft, between the two..(I will temp bring down the Mosley to 40 FT, (Lowering on the MAST)..

Assuming, there is 1 “S” Unit difference, I could indicate for my meaningless test, that is cost me, 2000(USD) per S Unit or if there is 2 “S” Units difference it cost me 1,000 (USD) and so on .. When comparing to the HEX Beam costs (500 USD)

Or lest say there was no difference, or better HEX Beam out performs, who knows.! But I am sure we all heard that the HEX Beam is 3 to 4 db of gain, and really the MONO Bander 3 element is a MAX of 6dbd (Above a Dipole, more likely 5.5dbd, although Mosley indicates 8dbd)…And we all heard the claims, that HEX beam works well at lower heights, well now, it will be only 5 ft below the MONO Bander

So, forgive me, if 6db is per S Unit, and the HEX Beam has a gain of 3 of 4 dbd, there should be very little difference, especially since the MONO Bander wiill have a gain of MAX of 6dbd (In reality) Also, only 5ft different..

As I said, this is an experiment, I don’t care which works better….Great stuff though (For me, at my location..)!

If the HEX Beam work less the MONO Bander I will use it for 17, 15, and 10 Meters..If they are the same performance. I will sell the MONO Bander and put on the Tower ( I will sell to someone who desires to stack the antenna..

The HAM community should embrace this comparison, who really has the time, space, and the money to do these type of tests? Yes, it is meaningless, worthless, but not for me..!
 
Best

NN2X

Tom Wright


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: G3TXQ on February 14, 2011, 06:28:36 AM
Tom,

Can you confirm what you said in your original post: that you called all Hexbeam manufacturers and were told by them all that a Hexbeam at 30ft to 35ft was a match for a 3-element monobander 10ft to 20ft higher?

Steve G3TXQ


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: WA8UEG on February 14, 2011, 06:33:23 AM
Hex beams are shortened 2L yagis.

A 3L yagi on a substantially longer boom should blow it away.

Test finished. :D

Oh Yea, count on it. Like compairing Randy Johnson's fastball to mine. 

I heard your fastball is pretty good.



40+ years ago about 83 MPH, today reversing the numbers would be close but would require a week of therapy to use the arm again. ;D


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: K0OD on February 14, 2011, 07:27:50 AM
"40+ years ago about 83 MPH"

My favorite piece of test equipment is my $900 Stalker Sport radar gun from my son's HS and college pitching career.  Frankly I got tired of hearing people (high school Dad's mostly) bragging about how fast their kids threw and I decided to see for myself.

My gun is the same one most pro teams use but it is far from being consistent.  I've watched multiple guns on tripods at minor league scouting sessions. Side by side guns can register many MPH different.

Never once found a pitcher who threw faster than claimed. As a general rule kids throw about 6 mph slower than the parents think. That's at HS level. By college, both kids and Dad's have figured out the disappointing truth. (notice how everyone thinks those carnival guns are way low? They're NOT)

But pitchers are like antennas. They have many parameters. We had a kid on our HS team with 1.60 era who topped out at 68 mph.

How fast can Dad's throw? I brought a very primitive device to my kids practice when he was about 12 (and Dads were younger). One 45-ish burly dad topped out at 56 mph.
 


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: WB2WIK on February 14, 2011, 09:14:10 AM
I threw a 90 mph fastball once.

It wasn't that hard.

Drove 90 mph in the car, opened the window, tossed the ball out.


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: K0OD on February 14, 2011, 09:24:12 AM
Coming back from an away game and bored with the long highway trip, I aimed my gun thru the (passenger side)  window at oncoming trucks. Gun measured up to 145 mph!

Pretty scary!


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: N9MXY on February 14, 2011, 04:16:24 PM
Longer ago than I care to think about I could serve a racquetball at 120MPH+ :-D


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: STAYVERTICAL on February 14, 2011, 07:14:10 PM
Hi Tom,

I think it will be very interesting to see the results of your tests.
In my many years of antenna construction and experimentation, I never fail to be surprised by the ways practical antennas vary from the theoretical performance.
Obviously, in the real world of residential ham antenna environments, many factors apart from the free space performance of the antenna come into play.
One thing I have found to really make an antenna punch above its weight is when the elements are closely coupled.
The bandwidth generally falls, but the gain and directivity rise dramatically.
It is of course difficult to match and is not a setup and forget system, but since I use a remote ATU on the driven element this is no problem.
Another factor is reflector element tuning, which can change the performance enormously, especially on a close coupled setup.
I use a small screwdriver motor to physically wind the ends of my reflector, and the change in front to back is huge at the sweet spot.
The hex beam is a fairly close coupled antenna, and from my personal tests with a friend about 30km away, it has an awesome front to back ratio, in his case anyway.

I also use a vertical with a diagonal reflector close coupled (6 feet away at the base), on 20m and it performs very well.
Not as good as a tower mounted 3 element yagi of course, but way above a naked vertical.
Again, I use a low speed motor on the reflector wire as a tuning unit to adjust for maximum front to back ratio.
If I had just blindly accepted the dogma of "verticals radiated equally poorly in all directions", or whatever other bias is prevalent, I would not be enjoying the benefits of my effective antenna now.
Too many people these days are "armchair generals/engineers/experts" and only serve as an anchor and brake to those who are excited and ready to experiment.

In the end, experimentation is what ham radio should be about - we are probably not going to find any hidden knowledge mystical antennas, but each one of us can add his or her curiosity-led findings to the mix.

Good luck with your tests and experiments - that is the real spirit of ham radio.

73s


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: N4JTE on February 14, 2011, 08:03:00 PM
Tom, I for one will look foward to the results, hoping you will write an article for eham on your findings. I occasionaly write comparison tests and run into the usual crap about correct testing facilities etc. but I have provided a lot of good real world info for other hams attempting wire antennas on 40 and 80. With you getting into actually testing the crazy gain figures published on these antennas on the upper bands your experiences will be well worth the effort and interesting to all of of not blessed with a convenient test range.
The test against a monobander should only go one way, but as you say those hex beam adds might have a lot of splaining to do, hi.
Have fun,
Bob


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: K0OD on February 14, 2011, 08:37:12 PM

Quote
"But imagine, if for example, the HEX Beam is only one S Unit less, (Which every one says is 6DB,)"

Truth is that one S-unit might just be a dB or two.

"S Meters are clearly not very accurate nor consistent, although some are better than others. In some radios, the S Meter calibration is a function of frequency. Your S Meter may differ from mine, even in the case of the same brand and model of radio. If you want to trust and know your meter, you should spend some time with your receiver and a calibrated signal source, mapping S Meter deflection to known dB changes."
http://www.seed-solutions.com/gregordy/Amateur%20Radio/Experimentation/SMeterBlues.htm


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: G3TXQ on February 15, 2011, 01:19:01 AM
OK - I'll ask the question one last time. If Tom declines to answer, I'll just have to speculate on the reason:

"Can you confirm what you said in your original post: that you called all Hexbeam manufacturers and were told by them all that a Hexbeam at 30ft to 35ft was a match for a 3-element monobander 10ft to 20ft higher?"

I have been involved with the hexbeam enthusiast community for about 3 years, and developed the Broadband version which is currently sold by K4KIO, DX Engineering and MW0JZE. I have no commercial interest in these companies but I do talk to the folk who run them. We have been keen within the community not to make exaggerated claims for the antenna's performance; you will find that philosophy reflected on my web site and, as far as I know, in the advertising from these companies.

That's why I was disappointed to hear that Tom had talked to these companies and was told the hexbeam at 30ft to 35ft was a match for a 3-element monobander 10ft to 20ft higher.

I also note Bob's throw away comment that: "those hex beam adds might have a lot of splaining to do, hi". Could he please say which ads he is referring to?

73,
Steve G3TXQ



Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: G3TXQ on February 15, 2011, 01:31:32 AM
In my many years of antenna construction and experimentation, I never fail to be surprised by the ways practical antennas vary from the theoretical performance.
My experience with developing the hexbeam has been the exact opposite. I am regularly surprised just how close the measured performance is to the theoretical predictions.

There's a page on my web site comparing measured performance with model predictions:
http://www.karinya.net/g3txq/hexbeam/eznec2/

73,
Steve G3TXQ


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: NN2X on February 15, 2011, 08:01:16 AM
Steve (G3TXQ)

Make no mistake about it, I was verbally told that the HEX beam is equal to the a 3 element Mono bander (3 Element), (By various HEX manufacturers) and does not need to be as high to get effective results..The 10 to 20 FOOT came from the claim of 50 Tower versus (MONO Bander), the a 30 Ft Tower (Hex Beam) comparison (Or at 35 FT). I am 52 years old, I have no reason what so ever to lie..It is not my character…So please lets move on…I am not going into a he said she said dialog, no matter what, you will never believe what I say, anyway..


But lets find some common ground..(And this is the most important)! And lets just say I was delirious on the phone with the HEX Manufactures

Now from this forum…Lets see if you at least agree with the below..


1. Hex Beam has 3 to 4 dbd of gain over a dipole (Correct)?

2. MONO Bander 3 element yagi has no more then 6dbd no matter the design (More then likely 5.5dbd)Correct?

3. Each "S" unit is 6dbd on HF Transceivers (Correct)?

4. Hex Beam works equally well even though at lower heights (In our case only 5ft LOWER)

5. If the above is correct, then when comparing the antennas, MONO Bander Yagi from Mosley at 24FT, and a HEX Beam, there should be very little difference, due to the fact the gain difference is only a max of 3db, between them..And considering each “S” Unit is 6 dB we should see a max of less then one “S” Unit

Note..I hope the HEX beam out performs, or equally to the Mosley to be honest..I will just sell the whole system, (2,000) Tower, Rotor and Antenna..And keep my 500 Dollar HEX Beam..(Push up mast / HEX Beam and rotor)

Best

Tom Wright

NN2X



 


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: NN2X on February 15, 2011, 08:10:58 AM
STAYVERTICAL AND N4JTE

Thanks for your support..!

This is all in the name of fun…To be honest, I hope the HEX Beam performs well…I get rid off the 2000 to 25000 dollar investment (Mosley, Tower, and heavy weight rotor!)! Rather keep the 500 Dollar investment (Mono Band Hex Beam, Cheap Rotor, and Push up mast)!

But I think, if the HEX beam does do well, it might be due that coupling factor, who knows..(From N4JTE)…And again no matter what my results, no one will believe it, any way. It is for me and my location, and all can here me on the AIR doing A / B Tests..

But make no mistake about it..I like quantifying the sales pitch, (On both sides),,,Mosley and Hex Beam..By all accounts this should only be 1 S unit difference, and if so..Great…If not, well, maybe that is why spend the other 2K

You notice, there is already some back peddling tone on the air!


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: G3TXQ on February 15, 2011, 09:57:49 AM
Tom,

Make no mistake about it, I was verbally told that the HEX beam is equal to the a 3 element Mono bander (3 Element), (By various HEX manufacturers) and does not need to be as high to get effective results.

So, you were not given this information by ALL hexbeam manufacturers as you claimed earlier! If you can confirm that your "various HEX manufacturers" includes those I mentioned earlier, I will speak with them about giving misleading advice.

1. Hex Beam has 3 to 4 dbd of gain over a dipole (Correct)?

Correct!

2. MONO Bander 3 element yagi has no more then 6dbd no matter the design (More then likely 5.5dbd)Correct?

Possibly - depends on the design. Cebik shows designs with just over 6.3dbd gain - I've no idea what the gain of your reference beam is.

3. Each "S" unit is 6dbd on HF Transceivers (Correct)?


No! I think you mean "dB", not "dBd"; dBd would have no meaning in relation to an S-meter. 6dB per S unit is an IARU recommendation, but few Receivers meet it. To quote you from another eHam posting:

"I know many of you, might indicate that an S unit is 6dB, I have not found that in practice, rather I found it to be more like 3db per S unit, just try taking a transceiver with a 100 Watts, and increase to 1000 Watts (Which is 10 DB increase which should only be 1.5 S units (If each Unit is 6 dB, but in reality there is sometimes 3 to 4 S units difference and this is due to the fact that between S 5 and S 9 there is only 3db for every S Unit."

I don't understand why you are now claiming 6dB per S unit on HF Transceivers?



4. Hex Beam works equally well even though at lower heights (In our case only 5ft LOWER)

The variation of hexbeam performance with height is no different than any other horizontal HF antenna.

5. If the above is correct, then when comparing the antennas, MONO Bander Yagi from Mosley at 24FT, and a HEX Beam, there should be very little difference, due to the fact the gain difference is only a max of 3db, between them..And considering each “S” Unit is 6 dB we should see a max of less then one “S” Unit

The difference in height between 19ft and 24 ft is worth about 2dB on a 20m DX path. So, allowing for a difference in Gain of 3dB - making a total of 5dB - I would expect to see somewhere just short of 2 S-points difference using your own figure of 3dB per S-point.

Other things to note:

* The two antennas will need to be far enough apart that there is no interaction between them
* If you want to get within a couple of dB accuracy you will need to take thousands of measurements. When I compared the hexbeam with a reference dipole using A/B switching there were many times the dipole was better than the hexbeam. It's only when you average the results over many thousands of readings you begin to see the underlying trend appear.
* You can only make the comparison on received signals because that's the only way you get control of the measurements.

73,
Steve G3TXQ



Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: K0OD on February 15, 2011, 10:56:57 AM
Quote
I don't understand why you are now claiming 6dB per S unit on HF Transceivers?

Dumbfounding, isn't it.  And what engineer [he has posted he's an engineer] seeks "common ground" rather than easily knowable truth?


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: KF6ABU on February 15, 2011, 11:51:35 AM


Now how about this HEX Beam, Here is what manufactures claimed, all you need is 30 to 35 ft, and this match any 3 element mono bander even if it is 10 ft or 20 ft higher..Believe me, I called them all and they all same the same thing Now, Mosley claims they have a 3 Element Yagi that can achieve more than 8dB above a dipole while only using 3 Elements on a 24 foot boom..
I will put the Mosley at 40 FT, and the HEX Beam is already at nearly 30 FT…OK, Let’s see…I will be on the air for all to compare, for at least 3 months…I love doing stuff like this…Again, I could care less who wins, I just purchased both of them,..
I will start these A B Tests around March 15.

This is a joke right? I think you are either trying to make a funny, or trying to make a comparison of products without actually thinking first.

Dx Engineering's site, wihtout even opening the manual states:

The DX Engineering MARK 2 HEXX antenna offers gain and front-to-back performance that exceeds your expectations for a 2 element beam.  Its unique shape is much smaller, better balanced and has been reported to receive less noise than typical beams. This lighter, easier to handle antenna can be rotated with a light duty rotator, and it performs well - even when mounted in the clear only 20 to 30 feet above the ground.

I dont think a single "educated" person would believe a folded yagi (hexbeam) can beat a mono band non trapped yagi at any height.

You claim you were told that, I doubt it. Based on what you have said I pretty much would doubt your claims about ANYTHING.

I'm not sure what you are trying to prove. Thus far you have tried to prove, through future tests that a 3 el monobander will outperform a 2 el hex beam. What will you try and prove next? The sun is hot? I'll spare you trouble.. It is.


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: K3JVB on February 15, 2011, 04:35:38 PM
I have a traffie 5 band Hex.

No doubt it works fine. Small foot print,only 20 pounds. But it will not perform as well as a longer boom mono-bander. It is what it is. A two element beam. 3 db forward gain..maybe. Decent front to back.
Great for many, maybe not for all.

No magic , just a good design....not a three element beam. IMHO
73
John


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: N4JTE on February 15, 2011, 08:58:39 PM
Wow, not sure why most of the posts are so vitrolic, the hex beam site claims 6db of gain over a dipole at the same height on 20 meters.
Well 6dbd of gain is comparitable to a three element monobander so why not put it to whatever test he can devise?
Bob


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: N4JTE on February 15, 2011, 10:01:33 PM
With ionospheric communication the HEX-BEAM's performance is comparable to larger conventional designs, and averages an apparent gain of 6dBd. A/B comparison tests were conducted at frequencies of 7-147 mHz. during an 8 year period. A summary of these "on air" tests is shown by the RP , from the website!
N4JTE


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: N3OX on February 15, 2011, 10:07:53 PM
Quote from: http://www.hexbeam.com/performance.shtml

With ionospheric communication the HEX-BEAM's performance is comparable to larger conventional designs, and averages an apparent gain of 6dBd.

Apparent gain.  That's a cute term.   :-\ 


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: KD8MJR on February 16, 2011, 09:28:59 PM
I say go for it, the results will be very interesting.

I am not all that old, but one of the things that I have observed in the last 10 years is the tendency for computers and the Internet to just stifle true innovation.  Yes I said that, and yes I know some of you are laughing your butts off, but it's true.  I like to experiment, and so many times I have heard people say OH that will never work, a quick search on the Net showed that you just cant do that!  Yet in many instances I get it done.  Just last week I had such an experience and the guy who said it shook his head in disbelief.   If people depend on NEC programs to tell them everything then not a whole lot of innovation will ever occur because I would bet good money that there are antenna designs that could be made that will show totally unexpected and different results from what a NEC model will show.

Anyway I know it's hard to argue this point, because computers do make great things happen, but at the same time they seem to limit this generation of engineers from thinking outside the Box.


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: N3OX on February 17, 2011, 07:14:02 AM
I am not all that old, but one of the things that I have observed in the last 10 years is the tendency for computers and the Internet to just stifle true innovation. 

You're thinking of the wrong people.  Much of the technological progress we see in 2011 relies almost entirely on computer-assisted design.  GOOD models of electronic systems work very well, and good models, creatively used, lead to innovation.

You don't have to be a professional engineer to make GOOD models of antennas.  You do have to spend time on it, and never stop learning tips on how to do it properly.  You have to make predictions and then you have to check them (or have other competent people help you check them) and see how the "real world" is different from the prediction.  This is good science. 

If you look at enough GOOD model/measurement comparisons, you start to see a pattern: outrageous claims based on computer models of antennas are often the result of some really flawed models where the MODELER made a serious mistake.  People leave out the feedline on antennas that are prone to common mode problems.  People neglect to include the 30 foot mast standing 20 feet away from their 40m vertical.   Often, people use the wrong type of model for the earth, breaking some numerical rules that are explicitly stated in the manual.  People don't do self-consistency checks on the model to see if the calculations are running into difficulties or not.  Some people base claims on models that show 300% efficiency because the calculation engine is choking on the problem.  Again, the way you check this is discussed in the manual, but some people don't bother.

This is not the fault of the computer tools.  It is a classic case of garbage-in, garbage-out.  If you don't know how to build good models and check for basic problems with the predictions, you're going to generate nonsense.

Quote
If people depend on NEC programs to tell them everything then not a whole lot of innovation will ever occur because I would bet good money that there are antenna designs that could be made that will show totally unexpected and different results from what a NEC model will show.

There are some antennas that don't lend themselves well to NEC simulation.  Some examples of this are antennas with lots of close spaced wires, lots of sharp corners near other sharp corners,  and antennas with tightly coiled parts that don't lend themselves well to approximation with lumped loads, like some helical antennas. 

But the flip side of this is that there are some antennas where free NEC-2 programs can predict the performance more precisely than any of us can actually measure.  Tubing and rod beams with elements insulated from the boom installed in the clear are common on the higher HF bands and VHF/UHF.  These are predicted very well, even by relatively inexperienced modelers.  If you spend some time reading G3TXQ's hexbeam pages, you will see what kind of impressive agreement you can get between models and measurement when an experienced, careful modeler and tester works on it.  You'll also see that some of the differences between the models and the real world measurements were the result of assumptions of what could be left out of the model, not because of a deficiency in the modeling tools hams have available.

Don't let some blowhard with a "quick web search" or a flawed NEC model with too many simplifications make you think that computer tools stifle innovation.  For many of us, computer tools lead us in new directions that we NEVER would have had the time or resources to go without them.  And even slightly over-simplified models can often result in built antennas that work "good enough" in the real world with no adjustments. 

It's been a long time since I put up an antenna I thought was going to be better than what I have already and found that it was worse.  It's been a long time since I had to spend more than five or ten minutes tuning an antenna, and even then, I didn't have to cut wire.. .I just had to twiddle a capacitor in a matching network a twentieth of a turn.    Not all of these antennas measure exactly the same as the predictions, but they're close enough that there's not much point in tweaking them, and they're close enough that errors in my measurements, especially on a small lot with limited time, are probably more serious than errors in the models.

===========

If you don't LIKE modeling stuff and you just like to go outside and experiment, that's great!  Do it!  But don't be excessively skeptical of modeling in general.  Be careful and test things, but don't assume that models can't describe reality when done well.  They can.    And don't assume that measurements are free of errors and problems.   Measurements also have a set of strong assumptions and antenna interactions can be a SERIOUS problem.   Measurements can generate nonsense just as much as models can.  Maybe more.  People will argue that their 80m double bazooka is 18dB better than their 80m dipole, and then you find out they hung up the two antennas about 0.2 wavelength apart and therefore built themselves a wire beam... and really that 18dB is just 10dB because of an "S-unit" assumption.  People will sometimes invent things out of thin air when their measurements show one antenna to be surprisingly better than another.  They thank their good luck and move on, firmly believing their mistake was a result of a good measurement.

Don't get me wrong: real-world measurements are very important.  They're very satisfying and make you feel good about your antenna.  They're important checks for modelers.   But they're very messy and error-prone, and if you want to ACTUALLY know things to within a few dB it is very difficult and time consuming.  If you don't do the difficult and time-consuming part and you don't give enough space between antennas, you're just fooling yourself.   Richard Feynman put it well in talking about science in general:

Quote from: R.P. Feynman
The first principle is that you must not fool yourself and you are the easiest person to fool.

Honestly, the hams I trust most to know how antennas work are people who model things and then make sure that those things get measured, and then think really hard about any differences.  Models help tell you what you're doing wrong with your measurements and measurements help tell you what you're doing wrong with your models.  So people who do both are constantly "checking their work" in a way that ensures they don't fool themselves.

Other people who FULLY trust anything NEC programs say without even doing the self-consistency checks are fooling themselves.  And people who "measure"  two tightly coupled antennas, who assume that 6dB per S-unit is a universal truth, and people who do a couple spot check "measurements" and call it a day are also fooling themselves.   

Quote
at the same time they seem to limit this generation of engineers from thinking outside the Box.

What box do you want people to think outside of?  Professional engineers have full three-dimensional finite element software that solves Maxwell's equations for anything.  And if you're thinking of thinking outside the box of established electromagnetic theory you've got a huge body of work to overcome.  We have tested the heck out of electromagnetic theory.  It is  simply an excellent predictor of how electromagnetic fields behave.  As with any scientific "fact," classical electromagnetic theory is subject to change as we discover new things.  But those new things will come from subtle and exotic experiments that cost millions of dollars.  There will be no antenna breakthroughs based on someone discovering new physics in their backyards.  Anyone who says they have "new physics" on their side is either trying to sell you something or really fooling themselves or both.

There are lots of new ways to use the established physics (like metamaterials), but many of those really need computers to search for good, weird designs in the infinity of possible antenna designs.  It is possible to luck on to a good weird design in your backyard.  I won't deny that.  But then you really have to make sure it's as good as it seems, and that requires more testing than most people do.  People are scared of having their "innovation" debunked.  But it's not an innovation unless it stands up to serious attempts to show that it's NOT an innovation.


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: STAYVERTICAL on February 17, 2011, 02:04:24 PM
Dan (N30X) makes a very compelling and accurate argument about the veracity of good mathematical models in predicting real world outcomes, as would be expected from a professional scientist.
But, to some extent, herein lies the problem with both ham radio and many other pursuits these days.
There is amnesia from many people that ham radio is a hobby, a diversion, a recreation activity, not a peer reviewed government grant funded scientific program.
The modern reliance on models by "professionals" leads to laziness, and non-imaginative thinking.
When we look at most of the modern foundations of physics, electronics, mathematics, and many other scientific areas, the fundamental axioms were laid down by people not using models and computers.
Many of these insights were "eureka" moments which are peculiar to the human race.
Einstein, with his riding on a beam of light, Kekule with his snake eating his tail benzene ring are examples of the imagination and peculiar power of the human mind to transcend simple iterative thinking.
To elevate models above their place as a simple tool, is to deify a hammer for helping you build a house.
Today, there is a still a great divide amongst pure mathematicians who seek to further the art by thought and those who use models to either iteratively or deductively prove truths.
A neural network, for example, is despised by those who would seek to use an algorithmic analysis of problem solving, but they are both extremely useful, and in fact the basis of our brains.
If, as Dan said, the models were used with skepticism, they would be an extremely useful tool - but like relying on the output of a calculator without doing a quick sanity check of the answer, you could end with truth which is a lie.
Modern day examples abound of so called professional scientists using models with, as Dan said, garbage in garbage out.

The English met office, with its vast arrays of supercomputers and professional modellers can't even predict massive snowstorms which have hit the country for the previous three years.
Nasa, with massive computer power and expertise can't predict the sunspot cycle will be a weak one, instead predicting a massive one which never happened.
Global warming models have been shown to be laughable and best used as comedy skits on late night TV.

Yes, if models were used by scientists without built in biases, and without funding depending on giving a certain point of view, they would indeed be valuable.
But, in todays world of lobby groups and money going to where the models outputs is most desirable, I think I will put more faith in the backyard experimentalist.

73s


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: KD8MJR on February 17, 2011, 03:11:14 PM
Amen StayVerticle Amen...


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: KD8MJR on February 17, 2011, 03:21:47 PM
Dan very nice write up, and it's true that given a person uses a modeling system properly they will most likely get accurate results, the problem for me is that modeling programs are now used in Realms were the outcome of such can be inaccurate and in these cases a possible break through is overlooked because a modeling program says it won't work.  A perfect example of this is all these bloody weather modeling systems, they seem to be as accurate as just looking at a Satellite picture and taking a guess!   In cases like this if the human brain was used a bit more I bet some obvious reasons would be found, but instead people will plod along trying to tweak the current algorithms because no one wants to admit the software may be working with algorithims that are missing many small but vital components that just cant be worked out without a human  discovering whats missing by using pure grey matter research.

All in all I find myself worried for my own kids, I see a world emerging where the skill sets of most kids have no real value except in the cyber world.


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: K1BQT on February 17, 2011, 06:55:12 PM
Anybody thought about E-plane nulls? Isn't it possible that, over ground,  the higher gain Yagi will exhibit deeper E-plane nulls than the Hex so that signals at SOME arrival angles might actually measure stronger on the Hex? Of course the larger antenna will wipe its butt at all other angles, but the manufacturer probably forgot to write those data points down! Same for the H-plane pattern, too, where the Hex has less directivity. ;)


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: G3TXQ on February 18, 2011, 03:55:44 AM
I don't think you'll see any significant difference between the on-axis elevation pattern of a 2-el hexbeam and a 3-el yagi. The Gain advantage is predominantly caused by the difference in azimuth patterns.

Steve G3TXQ


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: G3TXQ on February 18, 2011, 04:36:06 AM
I view the antenna modelling issue very differently from STAYVERTICAL.

Whilst developing the broadband hexbeam I found that the availability of EZNEC actually encouraged innovation. I had many ideas about how the antenna might be improved, but I could never have evaluated all those ideas experimentally within a sensible time frame. EZNEC modelling allowed me to discard the least promising ideas and focus my practical experiments on the most promising.

When the practical work started, the close agreement between EZNEC predictions and my measured results gave me confidence that the ideas which I rejected because of modelling results had not caused me to "miss a trick".

For me, the ability to test ideas using modelling is a real encouragement to innovate.

Steve G3TXQ



Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: K1BQT on February 19, 2011, 04:20:50 AM
I don't think you'll see any significant difference between the on-axis elevation pattern of a 2-el hexbeam and a 3-el yagi. The Gain advantage is predominantly caused by the difference in azimuth patterns.

Steve G3TXQ

Two different Yagis -- one with significantly more gain -- mounted at two different heights over real ground won't exhibit significant differences in E-plane pattern nulling? I can't agree, but perhaps a little modeling will prove me wrong!

Rick  K1BQT 


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: G3TXQ on February 19, 2011, 04:43:00 AM
Two different Yagis -- one with significantly more gain -- mounted at two different heights over real ground won't exhibit significant differences in E-plane pattern nulling? I can't agree, but perhaps a little modeling will prove me wrong!
Rick,

I should have been more explicit. My comment applies to antennas at the same height over the same ground. A Dipole, a 2-el Yagi, a 3-el Yagi all have very similar elevation characteristics - the gain differences predominantly come from the concentration of energy in azimuth.

That comment becomes less valid as you increase the number of Yagi elements.

73,
Steve G3TXQ



Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: NN2X on March 01, 2011, 03:32:36 PM
Update, on the HEX Beam, here in Allen Texas last week the winds were strong, and the mast broke..The antenna came down,...So there will be no comparison..

The mast by the way, came with the antenna...

Best

Tom Wright


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: N3OX on March 01, 2011, 03:41:48 PM
Update, on the HEX Beam, here in Allen Texas last week the winds were strong, and the mast broke..

Bummer.  Sorry to hear that.

Winds took my flag receiving antenna down the other day but fortunately it survived the topple mostly intact.


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: K0OD on March 01, 2011, 03:46:42 PM
So the little hex at 30' came down when the "mast broke." 

What's the story on the much bigger wide-spaced Mosley due to arrive there from the factory in a week to go up 10' higher than the Hex?


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: NN2X on March 01, 2011, 04:55:49 PM
K0OD. The mosley is scheduled and on time. Thanks for your concern


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: N4KC on March 02, 2011, 03:20:16 PM
My own experience with a homebrew hexbeam is detailed in this article:

http://www.eham.net/articles/25352

My new beam (K4KIO version) is doing great and survived a 70 mph wind gust last week and some pretty good ice last month.  NN2X, hope you can get yours back up and radiating quickly.

Now, I still think that the concern expressed by G3TXQ about the original post is still valid, and his questions have not been answered satisfactorily.  NN2X made a serious charge against a number of manufacturers, and, as Steve mentioned, it would surprise...no, shock...me if the charges were true.  I have done business with DX Engineering and K4KIO and, since I make part of my living in marketing and advertising, I have observed their business practices and ads--as well as Mike Traffie's--from afar.  I have always been impressed with their honesty and truth-in-advertising.  If they or others did make the claims NN2X mentions--and he says they ALL did--it would be a good thing to know. 

If they didn't, somebody owes somebody a retraction.

Don N4KC
www.n4kc.com
www.donkeith.com


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: KO7I on March 20, 2011, 09:03:50 AM
I am curious, do any of these mfr's make a 40M version of the HEX Beam?

73, Don KO7i


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: G3TXQ on March 20, 2011, 09:53:24 AM
I am curious, do any of these mfr's make a 40M version of the HEX Beam?

I'm pretty sure not! Home-brew versions have been constructed:
http://www.linehand.com/k7hc-MegaHex.htm

73,
Steve G3TXQ


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: KO7I on March 20, 2011, 11:26:31 AM
Thanks, very impressive. 73, Don KO7i


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: KM6CZ on March 27, 2011, 12:32:46 PM
I have both the TA-33M and a home brew hexagonal beam... the TA-33 is better at front to side but nothing else. (May be height limitation for the yagi) From a practical perspective, the hexagonal beam outperforms the TA-33. This should come as no surprise as the TA-33 did not do well against other triband yagis (See HF Triband Performance by Silver and Morris, dated but still available.)


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: KH6DC on May 03, 2011, 05:12:59 PM
Like N3OX and STAYVERTICAL says, this is a hobby not a research project funded by the NSF.  I use numbers from models as a guide taken with a grain of salt and prefer actual real world experiences though numbers will be different worldwide due to gulp, differeing locations.  Yes the the government couldn't predict those snowstorms, Nor'easters, tornadoes, Japan Earthquake/Tsunami, etc.  AND, who wrote the EZNEC base software?  The US Navy, as isn't it based on the Navy's NEC4 software?

I think we're just getting too serious as indicated by all the posts.   Let's just see what the results are (or was if I missed them) and move on.  All I can say is I love my SteppIR BigIR vertical and it's better than the vertical antennas I've had before.

73 Delwyn KH6DC


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: KA7NIQ on May 08, 2011, 07:39:00 PM
I have both the TA-33M and a home brew hexagonal beam... the TA-33 is better at front to side but nothing else. (May be height limitation for the yagi) From a practical perspective, the hexagonal beam outperforms the TA-33. This should come as no surprise as the TA-33 did not do well against other triband yagis (See HF Triband Performance by Silver and Morris, dated but still available.)
I have always wondered about that tri bander test, I never read it, but I heard the Mosley antenna did poorly.
Someone told me the KLM antennas won that test, but how many OLD KLM antennas do you see still playing ?
Here in Florida, the linear loading traps corrode, but plenty of old Mosley's live 25 years or more!
Something to think about ?


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: KY6R on May 09, 2011, 05:58:46 AM
I have had great experiences with Moxon's, but have settled on this antenna, which performs almost exactly - band for band - as well as my 2 element SteppIR at a mere fraction of the cost (I'm quite embarrassed to say):

http://www.bvarc.org/Tech/CompactW8JKBeam-K5LJ.pdf

Les Moxon, G6XN covered this W8JK modified design in his "HF Antennas for all Locations" book (2nd Edition), and it cost me $50 to build. I had tried a "regular" W8JK a few years ago - and was not happy with it. Amazing what happens when you change the feed.

This antenna is very light, looks very "stealthy" as compared to a Hex beam, and while I think the Hex Beam seems to be a fine antenna, this little known Moxon design has prevented me from bothering with a Hex beam or a 3 element trapped yagi - or other heavier, more expensive antennas.

Mine is up 40' on a Channel Master push up mast and turned with an $85 Channel Master rotator. Its been up 1 year now.


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: KA7NIQ on May 09, 2011, 06:26:33 AM
I have had great experiences with Moxon's, but have settled on this antenna, which performs almost exactly - band for band - as well as my 2 element SteppIR at a mere fraction of the cost (I'm quite embarrassed to say):

http://www.bvarc.org/Tech/CompactW8JKBeam-K5LJ.pdf

Les Moxon, G6XN covered this W8JK modified design in his "HF Antennas for all Locations" book (2nd Edition), and it cost me $50 to build. I had tried a "regular" W8JK a few years ago - and was not happy with it. Amazing what happens when you change the feed.

This antenna is very light, looks very "stealthy" as compared to a Hex beam, and while I think the Hex Beam seems to be a fine antenna, this little known Moxon design has prevented me from bothering with a Hex beam or a 3 element trapped yagi - or other heavier, more expensive antennas.

Mine is up 40' on a Channel Master push up mast and turned with an $85 Channel Master rotator. Its been up 1 year now.
It would be nice to see a picture of it ?
It looks very very interesting!


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: KY6R on May 09, 2011, 10:05:11 AM
The picture of the Moxon - modified W8JK that I built is here:

http://eastbayarc.org/pdf/wire_arrays_for_dx-ing.pdf

You'll need some patience to download though - it also shows an excellent modified Bruce Array for 40M that I used to snag ZS8M - which I could not have done using just a single vertical.

This is a presentation that I gave at Pacificon and at a few local club meetings in the SF Bay Area.

Hope this gives a few new ideas on how to build gain wire antennas on the cheap.


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: REMOVED_ACCOUNT_2015-01-09 on October 26, 2012, 03:54:27 AM
hahahahaha. I was looking forward to these tests for "fun".




Update, on the HEX Beam, here in Allen Texas last week the winds were strong, and the mast broke..The antenna came down,...So there will be no comparison..

The mast by the way, came with the antenna...

Best

Tom Wright


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: NN2X on March 26, 2013, 05:39:17 AM
Around the 2011 in Feb, I tried to compare the Hex Beam  to the Yagi Mono bander, and the antenna broke (The Mast)...This was my fault...nothing to do with the Antenna

However, since then K4KIO created a Hex Beam that was modified HEX using G3TXQ...Iordered this antenna, for my comparison


For the comparison, I will switch from Test System A to Test System B using each of the 15 Meter antenna arrays

For test A System, I have a 45 Tower and a 10 foot mast, with a 3 element Mono Bander (Yagi) from Hy Gain, using a 12 foot Boom, up at 50 feet., with Install, concrete, yeasue rotor, and I have two other Mono banders (20 Meter 3 element, and 4 element mono bander for 10 meters) / Costs nearly 7,000 (USD)


For test B System, I have a 25 mast, with a radio shack rotor, and Hex Beam (K4KIO / Using G3TQX Design), costs about 750 (USD)

Results, quite frankly, astounding...The Hex beam performed only 1 S unit less then the mono bander, and I will conclude if the antenna was up at 50 ft (The Hex Beam) the results would be at least the same..

The bootom line, if I would had went the Hex Beam route, and put up the 50 ft mast, there would had been very little difference, and I would had saved, 6,000 (USD)..

My antenna systems is on QRZ Site (Just plug in NN2X), and you will see the antenna systems (Hex and Mono Banders)


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: KA7NIQ on March 26, 2013, 07:07:02 AM
Around the 2011 in Feb, I tried to compare the Hex Beam  to the Yagi Mono bander, and the antenna broke (The Mast)...This was my fault...nothing to do with the Antenna

However, since then K4KIO created a Hex Beam that was modified HEX using G3TXQ...Iordered this antenna, for my comparison


For the comparison, I will switch from Test System A to Test System B using each of the 15 Meter antenna arrays

For test A System, I have a 45 Tower and a 10 foot mast, with a 3 element Mono Bander (Yagi) from Hy Gain, using a 12 foot Boom, up at 50 feet., with Install, concrete, yeasue rotor, and I have two other Mono banders (20 Meter 3 element, and 4 element mono bander for 10 meters) / Costs nearly 7,000 (USD)


For test B System, I have a 25 mast, with a radio shack rotor, and Hex Beam (K4KIO / Using G3TQX Design), costs about 750 (USD)

Results, quite frankly, astounding...The Hex beam performed only 1 S unit less then the mono bander, and I will conclude if the antenna was up at 50 ft (The Hex Beam) the results would be at least the same..

The bootom line, if I would had went the Hex Beam route, and put up the 50 ft mast, there would had been very little difference, and I would had saved, 6,000 (USD)..

My antenna systems is on QRZ Site (Just plug in NN2X), and you will see the antenna systems (Hex and Mono Banders)
And, if you had ordered your Hex Beam from NA4RR instead of K4KIO, you would have saved nearly 200.00 !
Both the K4KIO and The NA4RR Hex Beam are based on Steve Hunt's design (G3TXQ), and both antennas seem very well made.
The NA4RR Hex Beam simply costs less (nearly 200.00 less) then the K4KIO version of the G3TXQ Design.

I did not go with a Hex Beam, because I wanted 40 meters. I went with the Hy Gain Explorer 14, and the 40 meter add on kit.
The NA4RR Hex Beam would have given me 17, 12, and 6 meters that the Hy Gain Explorer 14 does not, but oh well ...

Glad you made your comparison, and thanks for posting the results!


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: K0OD on March 26, 2013, 08:00:27 AM
Quote
The bootom line, if I would had went the Hex Beam route, and put up the 50 ft mast, there would had been very little difference, and I would had saved, 6,000 (USD)..

I believe several posters predicted such a result. A silly waste.
 


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: WH7DX on March 26, 2013, 11:54:37 AM
NN2X, 

Thanks for sharing your information.

I've been using a Hex Beam from K4KIO for about a year or so now.   Works very well.  Light, fairly small..  cheap.. I have 6 Bands on it, simple galvanized fencing poles holding it up.   LP around the world when conditions are right.  Can't complain.   Great antenna.

I believe it matches up very well with a 2 element Yagi.. which it basically is.

The difference between a 3 and 2 element might be 1/2 to 1 S unit I believe.

I'm thinking about going with a SpiderBeam when it's time to replace the hex beam (salt water / wear)... The SpiderBeam is about 12ft wider, same weight and represents a 3 element yagi.

So, for the same cost, same weight and close approx. size..  I'm thinking take a little more.   It's like going from a 800W amp to 1200+ watt amp... right there.

There is NO WAY I'd deal with the cost, sight, hassle and danger of putting up a tower anywhere near my house when I could put a Hex or Spider antenna and paint it flat black and make great contacts.       

Bryan
WH7DX


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: KA7NIQ on March 26, 2013, 12:25:09 PM
NN2X, 

Thanks for sharing your information.

I've been using a Hex Beam from K4KIO for about a year or so now.   Works very well.  Light, fairly small..  cheap.. I have 6 Bands on it, simple galvanized fencing poles holding it up.   LP around the world when conditions are right.  Can't complain.   Great antenna.

I believe it matches up very well with a 2 element Yagi.. which it basically is.

The difference between a 3 and 2 element might be 1/2 to 1 S unit I believe.

I'm thinking about going with a SpiderBeam when it's time to replace the hex beam (salt water / wear)... The SpiderBeam is about 12ft wider, same weight and represents a 3 element yagi.

So, for the same cost, same weight and close approx. size..  I'm thinking take a little more.   It's like going from a 800W amp to 1200+ watt amp... right there.

There is NO WAY I'd deal with the cost, sight, hassle and danger of putting up a tower anywhere near my house when I could put a Hex or Spider antenna and paint it flat black and make great contacts.       

Bryan
WH7DX
For what they are, Hex Beams do a decent job. But make no mistake!
They are no match for larger yagi and quad antennas.
LOL, serious contesters do not use Hex Beams.

The Spider Beam will crush the smaller Hex Beams, and it will also crush many smaller tribanders as well.

To some "the little bit of difference" between a Hex Beam and a larger Yagi or Quad is not important.
But, in a pileup, even a DB or so of Gain might mean the difference between being heard, or not.









Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: PD2R on March 26, 2013, 03:56:52 PM
Brian WH7DX, please be advised, I think a Spiderbeam is not as strong as a Hexbeam. I own a Hexbeam and together with 2 other hams I also own two Heavy Duty Spiderbeams.
We really love the Spiderbeams for portable use but I don't want to put one on my roof permanently. It's very light weight but it is also pretty large.
In fact, one of our hexbeams was owned by one of our Danish friends who had it installed on a 50 ft tower. It broke one of the fiberglass spreaders during a mild storm. Maybe that particular spreader was flawed to begin with, I don't know.
Now, I'm not saying Spiderbeams are bad, heck we own two of them!. I'm just not sure they are as durable as a Hexbeam.


73, Maarten PD2R/OV2T


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: WH7DX on March 26, 2013, 11:11:50 PM
I believe the original spiderbeams were a little weaker.   Some were using the DX portable antenna's (in a bag) for full time use which they weren't designed for..  they have heavy duty spiderbeams now meant to be mounted full time.. or just build your own.

As for the message regarding a spiderbeam have a noticeable difference with the hexbeam.. that's not the data.   It's a slight improvement.   Maybe 1/2 a unit or so.  I was just saying, if an extra 12 feet isn't a big deal, and the weight is the same.. then that little extra might make sense.

If you want to spend $5000 for a tower with a large yagi and deal with maintenance being a "serious" DX'r than it obviously won't stack up.. but I can't count the number of times a guy with a huge Yagi tower was amazed that I was coming LP 20k miles and was 59 with a little hex beam and 600w...   again.. I do have a good location..... 

For the average Ham.. both the Hex and Spider are great antennas covering 6M up to 20M unless you feel real ballsy and want to build a 40M   :)


 



Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: KZ4USA on May 31, 2017, 04:38:07 PM
Some people forget what gain a single Dipole has  W8JI will tell you.


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: AC6CV on June 03, 2017, 07:01:30 PM
The advantage of a hexbeam is multiband like 2 meters through 20 meters, no traps, low wind load, rotatable and reasonable gain. I've put up lots of antennas and that is quite an achievement.


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: KM1H on June 05, 2017, 02:13:10 PM
Some people forget what gain a single Dipole has  W8JI will tell you.

Will he?

In the real world and not theoretical, the full size 1/2 wave dipole is the standard of comparison and it has no gain. Additional gain, or loss, can be realized by its height and the ground effect gain.


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: N4KC on June 05, 2017, 02:40:55 PM
   
Actually...and I believe W8JI would agree with me..."gain" is a relative term. That is, "gain" of an antenna, an amplifier, or anything else that concentrates or increases a signal is always given in relationship to something else. The two primary "something elses" when it comes to antennas is a dipole in free space and an isotropic--or perfect radiator--source, which is theoretical and non-existent in the real world. An isotropic antenna is an ideal antenna that radiates its power uniformly in all directions. There is no actual physical isotropic antenna. Of course, for most of us, a dipole in free space is non-existent, too, since there is almost always some other factor, such as the dirt below it, the vegetation around it, or the kids' swing set next to it.

But a gain figure should be referenced between one object and another. A dipole has no gain over itself. A 3-element Yagi may have 10 db gain...over a known dipole, over a 2-element hexbeam, or over a wet shoestring.

(Definitions from THE AMATEUR RADIO DICTIONARY by Don Keith N4KC.)

73,

Don N4KC
www.n4kc.com
www.donkeith.com
 
 
 



Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: KM1H on June 05, 2017, 03:20:57 PM
But a gain figure should be referenced between one object and another. A dipole has no gain over itself. A 3-element Yagi may have 10 db gain...over a known dipole, over a 2-element hexbeam, or over a wet shoestring.

Using dBd has long been an accepted definition which translates to some gain above zero.


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: N4KC on June 05, 2017, 07:35:14 PM
 
Correct. "Accepted" but not always followed. Antenna manufacturers will often quote gain over "dbi," that perfect but non-existent radiator with no gain whatsoever. That number will always be higher than gain over a dipole in free space...dbd...which does have gain in, usually, two directions over the isotropic source.

73,

Don N4KC
www.n4kc.com
www.donkeith.com
   
   
 


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: W9IQ on June 06, 2017, 03:19:56 AM
The standard reference used in antenna engineering is dBi. All of the math in this discipline of engineering centers around the isotropic antenna. Even the Friis equation and free space path loss are based on the isotropic antenna.

A perfect dipole in free space has a directivity of 1.65 and therefore a gain of 2.15 dBi. Gain is defined as directivity times efficiency and typically expressed in dB form with the isotropic as the basis for comparison.

But if you build a dipole and install it close to earth, the efficiency can be quite high (but not 100%) and the ground reflections will often increase its directivity. So you have a real world dipole that has gain over a theoretical dipole. To say the least, it can be confusing to say your dipole has a gain of 2.5 dBd, for example.

In any case, saying an antenna has a gain of 7 dB, for example, is an ambiguous statement. An antenna engineer would assume dBi if there was no other contextual reference. Antenna manufactures will almost always reference dBi gains because it presents the highest gain figures.

Also take note that the unit abbreviation is dB, not db.

- Glenn W9IQ


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: KM4AH on June 06, 2017, 04:37:52 AM
Am I wrong, or is there no such thing as gain without a corresponding loss in another direction ?


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: W9IQ on June 06, 2017, 04:55:23 AM
That is generally correct.

- Glenn W9IQ


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: KZ4USA on June 09, 2017, 10:05:02 AM
Its to bad they are strange looking:)


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: KE2TR on June 09, 2017, 11:58:26 AM
I find this comparison very interesting as to it was a real a/b test not some modeled software prediction. Back around the late 1990ies I had two 4 element  20 meter antennas  on 30' booms up on a crank up tower, top antenna was at 92' bottom at 40', I could also lower the top antenna to 55' by lowering the tower down. I also had a F12 C3E on another tower at 55' so in between contest I would do comparo's between these different antennas either at the same height or different heights. This is some of what I found at the same height above ground the C3E which is like a two element beam for 20 against the 4 element 20 was maybe 3 db down, the advertised DbD gain was 4.5 on the C3 and 6.6 on the 4 element, remember I said maybe 3db . If I compared the C3 against the lower 20 at 40' there was a very slight difference between the two and the 4 element was always slightly stronger, maybe just in the audio. Now if I compared the top 20 at 92' and the C3 at 55' there was always 6-10 db difference between the 4 element beam and the C3. Now for the ice cream if I ran the stack then it was a bigger spread more like 10 to 15db stronger on the two stacked antennas. I get exactly what NN2X is trying to convey, the cost per DB is insane as two what you have to spend on your install plus the time and effort needed for the up keep and maintenance of a big antenna far compared to the Hex on a simple mast and small rotor. After having owned a fairly competitive station for DX contesting and now not, when storms hit I sleep better at night for not having the biggest lightning rod on the block and keeping it simple gives the hobby a little more of the old school fun.
As far as gain the Hex beam has about the same gain as the normal trapped tri band beam about 3.5db, the forward stacked multi element forward stacked tri banders are about 4.5db and the 3 element monoband beams are between 5.5 to 6db and all these figures are DbD over a dipole at the same height  so you really got to go to better than 5 to 6 elements to get that 3db or better gain.
My hat is off to NN2X's comparo, great stuff!


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: ZENKI on June 09, 2017, 06:17:45 PM
All with un-calibrated S-meters,  It means nothing in the real world.

If you want to appreciate how hard it is to calibrate and make measurements using antennas read this guide

publications.npl.co.uk/npl_web/pdf/mgpg11.pdf

The National Physics Lab in the UK is one of the most respected calibrated labs in the world. When you understand how hard it is characterize HF antennas on a test range you will soon understand why most ham radio measurements  have little value when the very instrument that they are using does not even come close to being able to make a measurement with accuracy.

Nobody would buy or use a multi-meter with 200% inaccuracy to make voltage comparisons, yet we throw Db's and S-units  around like we have 1 db certainty! Even 100,000 dollar spectrum analyzers have uncertainties in their measurement accuracy of 1 to 1.5 db and hams want to use a S-meter and methods with probably 300% errors We are dreaming.

A good SDR like the Perseus and reasonably well calibrated LOOP we could probably measure these antennas accurately if we took care. We need to measure the differents within 1 to 2 wavelengths.

Maybe if we all joined the ARRL we could encourage them to set up a professional calibration test range. If everyone of us gave 100 dollars for building an antenna range we could measure these antennas with 0.5db accuracy. Now this would be an exciting project for ham radio research.



Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: KE2TR on June 12, 2017, 10:02:28 AM
NN2X has a very good point which Zenki fails to be able to read in these posts, a hex beam up around 30-40' costs about $600, even a Yaesu 450 rotor could be had for around $300 plus another 50-65 dollars for lower mast support. Then a slip up Rohn HD mast for under $200 plus maybe another $150 for very good guy rope. Maybe another $200 for rotor cable and good coax so were talking new about $1500 plus installation.
Now lets look at that stack of mono band beams which will run between $1500 to $2000, a HD 2" mast 24' long around $400 and we haven't even considered a tower which in this case lets say Rohn 45 at north of $200 for each 10' section so lets say between $1500 to $2000 for the tower/guys and hardware needed plus between $600 to $800 for a rotor to turn these antennas. Plus cables and if you cannot install it then were talking another $2000 for install so you have to invest anywhere between $8000 to $10K for w few DB in a pile up. Its the laws of diminishing returns and believe me I had my two tower Stacks of mono band beams years ago, was it nice Hell Yes but was it worth $30-$40K, hell no and I did that system for allot less than the fellows doing it these days.
Having a big antenna system means a few things, one is there is more to break down and fix, two lightning damages go up 10 fold along with storm damages,  You have to be committed or insane to do these things cause it's like racing a fuel drag car or a twin engine speed boat and that takes deep pockets. Sure is nice to have experienced it but I will never do what I did back in the 90ies again.
As far as real gain please read N6BT's array of light which sheds some great info into antenna gain, real gain along with efficiency.


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: W9IQ on June 13, 2017, 08:35:17 AM
Unfortunately, the hex beam will exhibit no gain over a comparable yagi. So all of the infrastructure comparisons are a wash.

- Glenn W9IQ


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: KZ4USA on June 13, 2017, 07:55:33 PM
NN2X has a very good point which Zenki fails to be able to read in these posts, a hex beam up around 30-40' costs about $600, even a Yaesu 450 rotor could be had for around $300 plus another 50-65 dollars for lower mast support. Then a slip up Rohn HD mast for under $200 plus maybe another $150 for very good guy rope. Maybe another $200 for rotor cable and good coax so were talking new about $1500 plus installation.
Now lets look at that stack of mono band beams which will run between $1500 to $2000, a HD 2" mast 24' long around $400 and we haven't even considered a tower which in this case lets say Rohn 45 at north of $200 for each 10' section so lets say between $1500 to $2000 for the tower/guys and hardware needed plus between $600 to $800 for a rotor to turn these antennas. Plus cables and if you cannot install it then were talking another $2000 for install so you have to invest anywhere between $8000 to $10K for w few DB in a pile up. Its the laws of diminishing returns and believe me I had my two tower Stacks of mono band beams years ago, was it nice Hell Yes but was it worth $30-$40K, hell no and I did that system for allot less than the fellows doing it these days.
Having a big antenna system means a few things, one is there is more to break down and fix, two lightning damages go up 10 fold along with storm damages,  You have to be committed or insane to do these things cause it's like racing a fuel drag car or a twin engine speed boat and that takes deep pockets. Sure is nice to have experienced it but I will never do what I did back in the 90ies again.
As far as real gain please read N6BT's array of light which sheds some great info into antenna gain, real gain along with efficiency.

I think you can build a 2El quad cheap and cover the Hexbeam bands  5 bands no problem and more FB and gain.
Just thinking, they have been around and tested for years. Just saying.


Title: RE: Real time Comparison with HEX Beam and Mono Band Mosley Yagi will be interesting
Post by: KE2TR on June 13, 2017, 09:58:07 PM
The current crop of quads sold on the commercial market are  all the same design, the spacing is set for one band but has you go up the spacing is good for 20&17 but way to wide on 15 and above . The only quad I have seen that really had taken care of that was that Qtenna which was like the old spider quad from Canada but I have not seen any add's anymore for this antenna but each band had excellent spacing.  Were the hex does very well is that each band has decent spacing and there is no need for elaborate matching. Were the quad has its short comings is in the spacing were FB ratio goes down as spacing between the two element increases plus its not a 3 dementional design .