The K1JJ Loops - First Time on the Internet

[Steve - K4HX]

Many of you have heard about or heard the signal from K1JJ's now famous 80-meter delta loop array. But most have never seen them. Yes, they do exist and I've seen them with my own eyes. I took photos over the years, but since they are wire and 140 (and more) feet in the air, often the photos don't show well. But I took a good one about a year ago. With some additional manipulation in Photochop, I was able to bring out the wires and show this beautiful array.

The two loops are the triangles hanging from the 40-foot long horizontal boom at the top of the tower at 190 feet. The average height of the loops (center) is 140 feet, making them effectively one-half wavelength above ground for best high-angle suppression.

You can see the feedlines connecting from the tower to the center-bottom of each loop. Notice how Tom guys off the loops so they maintain the correct spacing along the entire length. Everything is very symmetrical. There's a reason for his big signal.

Click on the photo below to see a larger image.

Enjoy.

[W9GT]

Very nice!  It is hard to imagine the scale and size of those loops....they look  like my 40 meter loops that are half the size.  Of course, my antennas are not nearly as high and they are diamond shaped, not triangles.  Wow, up 190'... that is super.  Yes Tom Vu is the channel master.  He is always loud here.

73,  Jack, W9GT

[Steve - K4HX]

Yes, the scale is hard to grasp, even when you see them live! At one time, Tom had some full-sized 20-meter Yagis up. Due to the size and height of the towers and the height of the 20-meter antennas, I thought they were for 10-meters. Then Tom, asked a couple of us to help him move one he had on the ground. Then I got a much better idea of the size and weight of those 20-meter Yagis!

For scale in the photo, the tops of the tree at the bottom of the photo are at least 60-70 feet high.

[KF1Z]

One of the first European signals I worked on 75meter slopbucket....with reallly low power ( under 10 watts, 4:1 swr,  ant 20 feet off the ground etc..)

Had a "full sized"  5 element Delta array for 75 meters.

He said it took 4 really tall towers, and LOTS of guy wires for the loops.


No wonder he could hear my PW signal!

[K1JJ]

Thanks for doing the photoshop on that Steve. It stands out like after an ice storm in that pic.  You be a good tech-spook!

For more info:  The base of each loop has a 4" diameter PVC pipe hanging there as the center insulator. There are about 12 turns of RG-213 wound around each as a choke balun.

After trying MANY different 75M antennas over the years, this is by far the best system into Europe - and the F-B is as good as anything I've tried, about 25db or so.  

About three years ago, I got crazy and put up an exact twin of this system on the other 190'er located 300' away. I fed them in-phase and saw the expected extra 3db gain into Europe. However, I decided to take the second set down and replace it with the 40M Yagi stack. Didn't want to risk interaction.  I do miss that twin phased system though, esp when trying to pull thru a weak one in the noise.


Thanks again - I added it to the QRZ group. Yes, that IS the first clean shot of the thin #10 wires from the ground.

T

[KR4WI]

Well, just who is this Tom guy anyways?  I heard him working dx stations a few weeks ago on 80 mtrs,  Is this his rx ant also?  because I could not hr the stations he was working....Matt KR4WI

[W1RKW]

W1RKW visits K1JJ.  I can affirm that the Delta Loops are impressive.  Indeed a nice setup and truly impressive in person.  A pic is good but seeing his antenna farm in person speaks volumes. And naturally, a demonstration of their effectiveness proves it.  Thanks for the demo Tom. I enjoyed our visit.
B

[Steve - K4HX]

It's like a visit a visit to a radio holy place/shrine/temple.

[K1JJ]

W1RKW visits K1JJ.

Dr. Love enjoyed seeing you too.

Yep, it was a fun visit today, Bob!  You were lucky cuz as Steve will attest, most guests do involuntary servitude around here.  The cold and deep snow saved your ass. 


I was looking at the Huzman's 40M loop thread today. I wonder how many built it? It has over 5,000 hits. Jack/GT, did you eventually go with that design or are you still using the driven /director config?

http://amfone.net/Amforum/index.php?topic=21534.msg153483#msg153483

Gawd, we are getting an ICE storm tmw. That's ALL we need.

T

[Steve - K4HX]

How much snow is left on the ground. If you get a nice coating of ice, that stuff will never melt. Your June prediction might be in jeopardy! 

I can't believe the number of times the 40-meter loop file has been downloaded. Even if only one percent of those who downloaded built one, that's 22. Can't say I've ever heard anyone on the air using one.

[K1JJ]

Good designs like that can sit around for a long time before people wake up. After you gets your new "Little Pup" on the air, theys gonna be axing what the heck kind of antenna youse gots there.  Before you know it, John / ON4UN will feature it in his next Low Band DXing edition -  and you be whirlwide famous, up for an academy antenna award!  [caw mawn   -ed]

T

[WA1GFZ]

I think Jack and I are the only guys running the HUZ design. It does work great with less than 2:1 VSWR across 40M. This morning I noticed the JS plastic bag over the transfer relay is ripped. Guess it will have to wait. We got close to 30 inches here but has compressed about 6 inches so far. Looks like another ICE test Tuesday afternoon.
The cat is bummed with all this snow.

[AF9J]

Oh my!!!  Those are big!!      What's the gain on them JJ?, about 6 dBd (like the the old homebrew 2-el quad I used on 2m SSB & CW 20 years ago)?  That's good antenna firepower on 80m!   

[Steve - K4HX]

It's not really mine, in that I'm sure others have built something similar or identical before. I took a few different ideas, combined and adapted them to my use.

When I talked to ON4UN on the air the a few weeks ago, he said the latest edition of his book is soon out (looks like it is out now according to the link below). He claimed this would be the last one he would do. The next one (if there is one) would be someone else's project. I nominate K1JJ. HA!


http://www.arrl.org/news/new-edition-of-em-on4un-s-low-band-dxing-em-now-shipping

Good designs like that can sit around for a long time before people wake up. After you gets your new "Little Pup" on the air, theys gonna be axing what the heck kind of antenna youse gots there.  Before you know it, John / ON4UN will feature it in his next Low Band DXing edition -  and you be whirlwide famous, up for an academy antenna award!  [caw mawn   -ed]

T

[K1JJ]

I think Jack and I are the only guys running the HUZ design. It does work great with less than 2:1 VSWR across 40M.

Oh yeah, that's right - I forgot you put up that boom on the tower for it.  When you and Huz finish up your new "Lil Pups"  we should get on and celebrate by holding triple court into Eu on 40.  You two will have serious pecker matching to sort out...

Ellen, yes the gain is around 5-6dbd at most.  The main advantage is the low angle on 75M for Eu. My dipole at 60' is often down as much as 15-20db compared to the loops. It's mostly angle of radiation since the difference between the two at the same height is only about 5-6db.  

And vice-versa - the high loops are usually way down for the high-angle locals compared to the dipole.


The cool thang about the Huz 40M  loops is get it up at 80' apex and the average  height is a good 1/2 wave high. That will basically duplicate my 75M loops in low angle performance.   The f-b on Steve's loops is terrific too. The driven design works well.

T

[WA1GFZ]

Yes that would be fun if we could find a time when the crap generator isn't trashing 40.

[Steve - K4HX]

Not FB on the local noise. That's gotta suck.

[K1JJ]

The ice is starting to build up. The 70' long, 40M Yagi elements have a strange weighted sway to them in the wind. It's supposed to rain/freeze more today and into the night.  Hope this doesn't turn into a New Hampshire-type disaster.  The problem is it will get cold and windy the rest of the week, so no ice melting. It had beter melt today or tmw or else-   Help me Mr. Wizard!

T

[WD8BIL]

Put some ac current in the loops, Vu. Heat that wire up. Worked on my quad in'97!

[W1RKW]

W1RKW visits K1JJ.

Dr. Love enjoyed seeing you too.

Yep, it was a fun visit today, Bob!  You were lucky cuz as Steve will attest, most guests do involuntary servitude around here.  The cold and deep snow saved your ass. 


I was looking at the Huzman's 40M loop thread today. I wonder how many built it? It has over 5,000 hits. Jack/GT, did you eventually go with that design or are you still using the driven /director config?

http://amfone.net/Amforum/index.php?topic=21534.msg153483#msg153483

Gawd, we are getting an ICE storm tmw. That's ALL we need.

T

I don't know Tom, I think I caught Fabio winking at me out of the corner of my eye when Dr. Love was looking the other way :-).  He's a looker!

As far as involuntary servitude goes, if you ever need a third hand, some extra muscle or even a spotter let me know. 

[W2PFY]

Well, just who is this Tom guy anyways?

Yes, who is it please