Jo-Gunn: Son of a Gunn

[Master Chief]

I've just had the pleasure of cutting apart a Jo-Gunn Son of a Gunn antenna.

Let me tell you, this antenna is HEAVY at the base! It should come at no surprise when you see that they use THREE layers of tubing in the base of this antenna!

Its also amazing, their use of woodscrews to hold this bad boy together! I used a hack saw to get the base apart, which is when I found the screws. They actually break off the heads and then slip the pieces together, covering the screws.

Now you may ask, why cut this antenna up?! Well, the previous owner cut the top tubing of the base assembly for some unknow reason. I wanted to fix this piece of aluminum and sell it, but I couldn't get it apart! The more I dug into it, it became clear that the base would have to be destroyed to get it apart, which would allow me to replace the previously broken section.

I got the antenna for free so what the heck! Out came the saw! (I'm cutting up a Maco V58 also. I'm doing a write up on how to convert your V58 to a V5000 with almost over the counter parts!).

What is interesting about this antenna is its height! 26'. I know of only one other antenna close to that length; the Sigma IV. This antenna uses 4 ground radial sloping down at a 45 degree angle and a gamma match, much similar to the Sigma IV. BUT, whereas the Sigma IV is only a half wave antenna, THIS antenna may truly be a 3/4 wave! (That should stir up the flies in here...right Bob!) But but, there is a weird sleeve inside the base section that may make this a different antenna altogether.

Also, this antenna does not use a coax connector. Not a bad idea as the coax connector is usually the weak link in an antenna system.

I may rebuild it. The base assembly is VERY easy to build with standard aluminum square tubing and a hole saw! I wouldn't have used wood screws, but maybe Jo-Gunn was trying to keep the base assembly a secret. I don't know.

I don't have the manual for this antenna so I'm not sure what the original tubing lengths were. I'm going to try to get one from the factory.

 

[Robalo]

I love to see some pictures.

 

[bob85]

lol chief, somebody put the son of a gun radials on upside down hahaha,
i will wager you one aircraft rivet that folding the radials upwards say to about 25/30 degrees from the vertical and retuning will increase the radiation in a favourable direction rather than stop the lower 1/4 radiating and forcing the radiator to act like a humble halfwave,

joking aside, you got my attention simply because the jogunn is unconventional,
get this thing fixed up and tuned correctly for max signal on the horizon and let us know how it compares to more conventional antennas,
i will eat my hat if that thing can = even the stock sigma4 at low angles to the horizon,
i look at it and see broken up lobes with lots of high angle ideal for short skips into europe,
nothing scientific of course just based on past experiments i have done with extended antennas,

ps why do you live 4500 miles away i have something longer and stiffer to show ya, you could not fail to be impressed :twisted:

 

[seedkey]

I too would like to see some pictures

 

[bob85]

hey chief are you saying the groundplane on the jogunn is capacitively coupled to the radiator and folded down rather than been directly connected and folded upwards as in the avanti????,
is either the radiator or the groundplane electrically connected to the supporting mast?

interesting antenna :!:

 

[distortion]

interested in the write up on maco v5/8 to maco v5000.

I have one on the porch that is going to come down for an i10k in the next few months if I don't find someway to convert it.

Josh

 

[Master Chief]

hey chief are you saying the groundplane on the jogunn is capacitively coupled to the radiator and folded down rather than been directly connected and folded upwards as in the avanti???? is either the radiator or the groundplane electrically connected to the supporting mast? interesting antenna :!:

Its really a simple design. The groundplane elements are electrically connected to the base tube and go DOWN at a 45 degree angle. The main element is also electrically connected (grounded) to the base tube (just like the Sigma IV). The antenna is fed with a gamma match (also like the Sigma IV) and is 26' tall (just a bit shorter than the Sigma IV).

So, the only thing capacitively connected to the antenna is the coax center cnductor via the gamma match. The rest of the antenna is DC grounded.

 

[Master Chief]

interested in the write up on maco v5/8 to maco v5000.

Hello Josh! Watch for it in the next few weeks! I'll post pictures and a parts list as well as where to buy the parts. I may even sell kits with a new assembly manual written by me.

It still won't beat the I-10K, but it will kill an A-99!

 

[distortion]

any word?

I ordered an i10k for me, but my dad is putting this v58 up since he burnt up his last antenna.. I sure don't want him to burn this one up

Peace,
Josh

 

[Marconi]

Hello Josh! Watch for it in the next few weeks! I'll post pictures and a parts list as well as where to buy the parts. I may even sell kits with a new assembly manual written by me.

It still won't beat the I-10K, but it will kill an A-99!

Hey MC, for me your last statement is ridiculous, but just in case it were possible, do you think this maybe why CB is dying? The I-10K has killed all the thousands of A99's out there!

You know, we never did get to test in the Mojave a while back, but had we done so could you now give us an idea of what you think those results would have shown? You must have some idea about those results in order to make such statements as noted above. Maybe you could give us a little description of those test and describe how and what the results were likely to show. I know you were planning to place monitoring stations at various points and then do some testing to these stations. If so, then give us a good guess as to what those results might have been. I know this will be a guess, but I would sure like to know what you mean when you say

It still won't beat the I-10K, but it will kill an A-99!

 

[Master Chief]

Distortion, I'll post the info on the V58 this weekend. I'm finishing putting one up for a local today and I'll take some pictures.

------------------------------------------------------

Marconi; always on the other end of the discussion. The I-10K works better. If you don't understand how or why, I'd be wasting my time here trying to explain it (yet again).

Since you own both, why not tell us why you think the differences between these two antennas are minor. Its quite possible that I can be wrong, but can everyone who owns one also be wrong? There are WAY too many people who agree with me and I don't kno of a single person who would agree with your summation.

The A99 has a lossy feed point. This can be tested by applying a few watts to the antenna and watching that power be converted into heat at the feed point, which WILL melt down. The quality of build is also lacking.

The A99 at $40.00 is a perfect example of "getting what you pay for." Does it work? YEP! Everything works.

 

[Marconi]

Distortion, I'll post the info on the V58 this weekend. I'm finishing putting one up for a local today and I'll take some pictures.

------------------------------------------------------

Marconi; always on the other end of the discussion. The I-10K works better. If you don't understand how or why, I'd be wasting my time here trying to explain it (yet again).

Since you own both, why not tell us why you think the differences between these two antennas are minor. Its quite possible that I can be wrong, but can everyone who owns one also be wrong? There are WAY too many people who agree with me and I don't kno of a single person who would agree with your summation.

The A99 has a lossy feed point. This can be tested by applying a few watts to the antenna and watching that power be converted into heat at the feed point, which WILL melt down. The quality of build is also lacking.

The A99 at $40.00 is a perfect example of "getting what you pay for." Does it work? YEP! Everything works.

Well MC I don't question that the I-10K works better and I did not suggest anything to the contrary. The simple fact that the I-10K has an effective GP attached tells us that it probably is the better design.

In other discussions you have claimed that the method of feeding also gives the I-10K a definite advantage. I have never read a definitive opinion on the subject of feed point losses while comparing one feeding method apposed to another. I mean one that really says one way or another. In fact, other than in the most general of terms, I have never heard you state why you believe the feeder on the I-10K performs better than other methods. You just throw out the claim. If you have such a report, then provide me the source. I can't prove my sense of the issue, but I do have an opinion on the subject. Maybe we could have a discussion specifically about that some time.

Sure the I-10K will allow for higher wattage input. This has only to do with the nature of resistance of conductors and conductor cross-sectional area. It’s just my guess, but I would imagine if one built an A99 feeder on the same effective scale as the I-10K then both would probably perform about the same under high power.

My argument here has only to do with your ridiculous claim of the I-10K being “the killer” as you note. It has nothing to do with my preference or understanding of which is better and why. You made the claims, I just would like to know how you come about those claims. You may be right and then I would have to rethink my experiences over all these years.

Happy Thanksgiving to all you guys!

 

[Master Chief]

Well MC I don't question that the I-10K works better and I did not suggest anything to the contrary. The simple fact that the I-10K has an effective GP attached tells us that it probably is the better design.

Many antennas have ground planes. This is not what makes the I-10K such an effective antenna.

In other discussions you have claimed that the method of feeding also gives the I-10K a definite advantage. I have never read a definitive opinion on the subject of feed point losses while comparing one feeding method apposed to another. I mean one that really says one way or another.

OK, so you HAVE read it somewhere else.

In fact, other than in the most general of terms, I have never heard you state why you believe the feeder on the I-10K performs better than other methods. You just throw out the claim. If you have such a report, then provide me the source.

I have stated over and over why i believe it has a superior feed system. You haven't been paying attention.

I can't prove my sense of the issue, but I do have an opinion on the subject. Maybe we could have a discussion specifically about that some time.

I can, and have. We can have that discussion again if you want.

Sure the I-10K will allow for higher wattage input. This has only to do with the nature of resistance of conductors and conductor cross-sectional area.

See, maybe you WERE paying attention! Good for you!

It’s just my guess, but I would imagine if one built an A99 feeder on the same effective scale as the I-10K then both would probably perform about the same under high power.

Let me save you some time......NOPE! But by all means, don't take MY word for it, build one and let us know what I already know.

My argument here has only to do with your ridiculous claim of the I-10K being “the killer” as you note. It has nothing to do with my preference or understanding of which is better and why. You made the claims, I just would like to know how you come about those claims.

The fact that the I-10K is superior to ANY other ground plane available today is not just MY opinion. Haven't you heard the others? You yourself own one and have said it is a better antenna. I call it "killer" because it just works better! I KNOW this because I've built them, tested them, rebuilt them, and have mucho experience with many other antennas. Do you think it is easy for me to say the the I-10K beats my beloved Avanti Sigma 5/8? I've done it and therefore, I KNOW!

You may be right and then I would have to rethink my experiences over all these years.

Me being right and you rethinking your experiences are two completely different subjects. Don't try to confuse the two!

 

[freecell]

"I just would like to know how you come about those claims."

the same way he comes up with the claim that the SigmaIV is a half wave antenna, just pulls it out of thin air in the face of countless factual instances of authoritative evidence to the contrary. if you didn't know any better you'd think he was a front man for the I10K. he's never disproven the fact that the bottom 1/4 wavelength of the SigmaIV does radiate and anyone would think that would be the coup d'etat that would settle the argument once and for all but that will never happen because field strength tests taken below his imaginary feedpoint confirm otherwise.

his continual barblike statements to the contrary are simply so much flamebait tossed out for the purpose of generating endlessly mindless discussions about something that is simply a non-issue among those who can read and are able to measure antenna parameters for themselves. it simply boils down to the fact that in his mind the SigmaIV just has to be a 1/2 wave to save face in the presence of his venerable ground plane.

in the meantime as opinion is stacked on top of opinion he robs others of the desire to go and find the answers to these questions for themselves by simply repeating the fallacy over and over again because as we know if the lie is repeated long enough and often enough some will inevitably consider it to be the truth as his ramblings go unchallenged. such is the existence of the self proclaimed antenna guru.

don't ignore your years of experience bob. it's the only thing that keeps you from buying into the lies and just remember, you're in good company. while there may be much to pursue, you have nothing to re-think and no good reason to do so.

"a man convinced against his will is of his own opinion still."
Dale Carnegie

 

[1200RI]

When it comes down to it in the real world. All of these ground planes are real close in gain.You can run a $50.00 ground plane and $450.00 ground plane.You are splitting hairs on gain.Now some are built better but that is about it.Cheerleaders flame on!