2 X 2 X 2 40M Yagi stack - progress pictures

[K1JJ]

Well, it's taken me all summer to get this far, but so far the 190' tower has been stripped, three 40M Yagis have been built and two have been raised.   I still have to raise the third one and connect them all up.  Had many other non-ham projects this summer, so progress was slow.


These are homebrew, 250 pound, full size, 40M Yagis built from scrap yard aluminum. The tower is a 190' self supporter, rescued from WATR in Waterbury, CT.  The reflector elements are 70' long - using NO coils, stubs or traps.

The three Yagis are stacked at 190', 125' and 62'. (Spaced every ~63' apart)  They are fed in-phase and will produce a single low take-off lobe at about 13 degrees on the horizon.  The reason for the stacking is to fatten up and compress the low vertical lobe and remove any high angle.

So far it's been a solo effort. I've built and raised the antennas with no outside help. Just raised and bolted on the second one today. The last one at 62' will be a piece of cake...  It's amazing what can be done with a lot of planning.  I try to minimize the number of climbs. It's something like a spacewalk where you don't want to forget anything.

I figure they will be operating by the middle of September.

BTW, the tower sections are 20' each. If you look closely at one of the pictures, you can see the bracket where the last Yagi will be bolted on. (at 62') The Yagi on the ground is #3, and will be ready to raise soon.

Wish me luck!

Tom, K1JJ

[K1JJ]

More shots:

[K6IC]

WOW !!  Things of beauty,  Tom.

Assume that for now at least,  these antennas will not rotate (?)

The first time I worked you,  Tom,  is was on 10 Meter AM,  and there,  too,  you were running 2/ 2/ 2/ stack,  but I forget what rig you were running.  This was in 2000 or 2001.

73  GOOD LUCK,  will be listening.     VIc

[K1JJ]

WOW !!  Things of beauty,  Tom.

Assume that for now at least,  these antennas will not rotate (?)

The first time I worked you,  Tom,  is was on 10 Meter AM,  and there,  too,  you were running 2/ 2/ 2/ stack,  but I forget what rig you were running.  This was in 2000 or 2001.
73  GOOD LUCK,  will be listening.     VIc

Hi Vic!

Yes, I agree – they are a thang of beauty.  I sometimes think I build these things just to put them up and admire…  no kidding.  It’s fun just walking around and checking them out.

Anyway… yes, the 2x2x2 is fixed on Europe for now. Europe is extremely hot now on 40M and the array has been optimized and modeled for the trip. The horizontal coverage is fairly broad, being 2el Yagis, so they will cover from Sweden to N. Africa and beyond.   I could always add ring rotators later, but I have another solution…

I think the 2x2x2 array would be much too low angle for USA. I’ve found for USA west, the angle is much higher on 40M, so I put up a three element wire Yagi at 70’ fixed west.  I did the same thing for S. America.  Also have a wire dipole at 45’ for the locals. So, with a coax switch I can switch any of the antennas to cover the major directions, in addition to a set of beverages in dual diversity receive. Should be loaded for bear this fall…     

I really like the 2x2x2 stack concept.  I plan to experiment with a 2x2x2 for 20M that is mounted as three elements – two driven els with a common reflector to give instant 180 degree directional changes. Add a second system and you’d have all four directions covered with no rotators.   Same thing for 10M.  I presently have long-boom stacked Yagis for 10 and 20M and wud have to recycle the aluminum. Maybe next year.

Thanks for looking and sharing the excitement, OM.

73,

T

[W1AEX]

These are homebrew, 250 pound, full size, 40M Yagis built from scrap yard aluminum. The tower is a 190' self supporter, rescued from WATR in Waterbury, CT.  The reflector elements are 70' long - using NO coils, stubs or traps.

Come on Tom. You need to think BIG! Only 250 pounds each? Sup wit dat?

(As previously stated, they are things of beauty! Nicely done! Be careful and good luck!)

[W2NBC]

           
        "It's amazing what can be done with a lot of planning"


Tom,

Your arrays and "planning" have long been iconic to piss-weakers like me (with single wires up near 100 ft).. It's like being in a locker room with a guy with REALLY big hands..

 I would love to read a journal or a JJ manual covering that planning and how you were able to get those big boys up alone, etc..

Anyway, congrats on the fantastic RF hammer pointing out east.. !!

73, Jeff

[K5UJ]

Hi Tom,

What a stick you have there and it looks nicely loaded.  Of course full sized elements are the way to go whenever possible.  You can't beat a commercial/professional grade tower with those 20' sections and flanges on the ends and thick wall or solid legs.  Surely you didn't stack the steel yourself though or do you have one heck of a gin pole?  Nice thing about those free standing 20 foot section towers is they can often be assembled on the ground and plunked down on a base with a crane.  What's the feedline out to the tower going to be?  I'm guessing 7/8" heliax?  Well if there's any AM activity on 40 in Eu you should be able to root it out with that.  On this end checked the currents on the feedline to the low band dipole and they're equal so the other near field antennas aren't unbalancing it surprisingly--had one of those great long QSOs last night on 3630 where the carriers were strong enough to blank out all the QRN--hope you get back on the air in a few weeks with no hitches.

Rob

[Steve - WB3HUZ]

Ah, you got the second one up. FB OM!

Great shots too. This is more momentous than a shuttle launch!

The Euros are gonna lose their minds. 

[WB2RJR]

Tom,

Good job and great pix.

I need to get the antennas up here in Wyoming and finish putting the shack together, but I spent my last 16 days off, fishing and riding my Triumph Bonneville.

Thanks for the inspiration, maybe I'll get it done in September.

73

Marty

[WA1GFZ]

Tom Vu running 3 duces on 40

[flintstone mop]

Tom, you will have to reveal the magic pills you take to give this type of energy. UN believable.

Prolly 20 dB forward gain and 50dB front to back

Be careful up there!!!! It sounds like you do solo work......not goodness

Fred

[WBear2GCR]

Shame... having to endure such radio hardships...

...maybe one day I too and others amongst us will have such onerous problems as well...     

               _-_-bear

[Steve - WB3HUZ]

As a famous Big Gun once said, "It's good to be king."

[flintstone mop]

TOM VU
Give up on being Hammy Hambone and become a short wave broadcaster. Three phase power and 250kw should do it. You can be da king of da air waves.

Phred

[KM1H]

That gives me a woody Tom You will have to bring lots of photos to Nearfest.

I would kill for a tower like that with no guy wires. It was a major multiperson affair to get a pair of 4 el 40M KLM's on my 180' Rohn 45 stick. And every time the top one broke it was a repeat and break they did due to the way the wind hits this hill above about 120'. Finally sold the good lower one and turned the other into a 2/2 sorta Cushcraft clones. Those are down now also as Im doing a reconfig of the commercial stuff that helps pay bills as well as constructing an obscene 6M array.

Id figure real world gain of 8.5 dBd for your stack and 15 dB F/R. The gain would seem like more in a stack due to the lobe compression and F/R can be greater or less at times. When the 4/4/4/4 for 20M was up I could feed several combinations that were real handy to follow propagation angle. All were individually rotatable which was another big plus. That was a key to winning DX contests.

Are you going to do switching such as low/middle, top/middle, and all 3?

Carl
KM1H

[K1JJ]

Thanks for the comments, guys!  It gives me more motivation to finish this project.  Today I finshed assembling the #3 Yagi and it's ready to raise up.  Still, so much to do around here.


Jeff/NBC :  Yes, there's hints and kinks for tower work that make it easier and safer. The key to going solo is using a tram line for a guyed tower or a simple pulley and rope for a self supporter - and using a vehicle to both pull up the antenna and at the same time holding tag lines to keep it going straight. No reason to need a big ground crew, etc. Once up, just climb up and bolt it on. Run the coax cable on your way down. Hang all your heavy tools, come-along, ropes, etc on the boom and pull it up wid the antenna. Less weight to climb with.  Use a safety cable line to climb with in case of a fall.  Bring up a water bottle to drink - and drain your log downwind.  Some complex climbs can last up to 4-5 hours.  Try to do as much as possible on each climb. Make them count, cuz there's only so much physical energy available.

Rob/UJ:   These are a pair of 190'ers that I put up about 11 years ago. They are solid steel, not pipe. The bottom 20' section weighs about 1500 pounds. I hired a crane to put it up. It wuda been way beyond my own capacity to do it with a gin pole, though some OT's still do it that way...   The feedline is 3/4" hardline with internal disk wafers spaced every 3" for very low loss dielectric properties. There is about 550' from the shack to the tower for the 40M array. That's about 0.6db loss on 40M.  No big deal.   Looks like your new antennas are working out beautifully - congrats.

Steve/HUZ:  Yep, it's as EZ as 1-2-3.  Or the Brooklyn ham might call it a "do over do over do."    The Euros are gonna lose their minds.... HA! I like that.  [I don't know if you guys realize that the HUZman holds court on 40M into Europe a few nights a week. The pile ups are legendary. That pair of switchable delta loops he uses is something that can be duplicated by the average ham with 60'-70' trees..]


Marty, FB on your Bonneville. I once rode a Triumph TR-6 bike to Calif and back. What a ride.

Carl:  What do you have planned for 6M?  I wonder if it's one of those stacked 2el Yagi arrays or is it a few big boom Yagis? 
The 2x2x2 on 40M has a sorta "curtain effect" so the model shows a f-b that is at least as good as a 3el Yagi. 25-30db is realistic. 2el Yagis stacked are a really good system.   I don't plan to switch them low/middle/top. I had up 2x2 40M Yagis before and found that 95% of the time the two in-phase was best. I also found this with the 10M 2x2x2 using a Stackmatch. I made it simple and just want to work the weak Euros at low angle. No corntesting here. Though I can imagine the stackmatch to be FB for corntesting as you have found.
Interesting on your 40M Yagi wind problems. Yeah, they sure can get beaten up with those long elements.

**  I took some closeup  pics of the third Yagi for construction tips - to be posted next:

Later -

T
 

[K1JJ]

Here's some close ups of the boom to mast plates, feeding system and boom.  This is the third identical Yagi ready to go up.

Notice I use a 4" ABS pipe with 8 turns of RG-213 wound on it and six ferrites as the balun chokes.  The driven element uses a solid 2.5" fiberglass rod as the center insulator to split the dipole halves. 

I use up to six u-bolts through the 1/2"! thick element to boom plate to keep the element from spinning on the boom. Wind, ice and other stresses can spin them. I also use two pins (1/2" bolts) thru the plate and boom.  I've once had a 40M Yagi spin an element in wintertime - never again.

All stainless steel u-bolts used throughout. Most of the ones you see have been recycled over the last 10 years and still look new. I sometimes cheap out on the bolts and buy regular plated steel, but always regret it when recycling. They are always rusted toast after a few years, though still strong. Heavily dipped galvanized bolts are not bad, however.

Notice the four bolts holding the boom together. I use 3.5" diameter aluminum pipe with 1/8" wall  to 3" boom.  The boom is only 17.5' long and is also trussed with a 1/4" steel overhead cable. It will be bulletproof for ice loads. The elements have no trussing, but are good for 1/2" ice at 130 mph according to YagiStress. 

I use TWO #10 teflon wires to connect the coax to each half dipole - with two copper lugs on each half element for redundancy. They are taped and  sealed with RTV and use their own bolts.  Connections are a problem with the WX, OM and I never use coax connectors out there. Everything is hardwired.

To match the 16 ohms of the combined three parallel 50 ohm Yagis, I built a coaxial 1/12 wave balun consisting of three 7.5' lengths of RG-213 in parallel - in series with one 7.5' RG-213. The single balun coax goes to the three Yagi feeders and the triple balun coax goes to the 50 ohm hardline up at the 125' level on the tower.  This should provide a reasonably low swr.

The resulting vertical takeoff lobe looks like a cigar aimed at the horizon, caw mawn. Coupled with a good f-b and high angle suppression, the s/n ratio shud be very good into Europe.

73,

T

[K1JJ]

Construction Pics - continued:

[K1JJ]

Happy Birthday Yaz!  Six years old on August 29th.

For a present, I'm taking him out sailing with a gourmet doggie lunch at his favorite spot...

[KM1H]

Tom, there will be 4 x 5el rotating on the mast above the 40. I dont want the wind hassle of long booms and massive H frames. This is a one man show. I have a HB long boom 8el at 60' now on the little tower and it is very effective. I'll leave it there as a benchmark.

On the side of the tower will be a 32 el collinear taking upn a lot of vertical real estate. They are a pair of 16 el Cushcrafts that I rebuilt with newly machined insulators and had one up fixed on EU for several years. Only 3 were custom built, mine came from Sam Harris, W1FZJ, and Wayne Green.

The footprint of this hill is rather small and falls off fairly evenly for 360* and as much as 450'. N1BV (ARRL antenna Book, etc) modeled it and K6STI included it in his Terrain Analyzer (TA) program.This seems to have the wind come in low and then get directed up and compressed by the slope and trees. The effect is huge when I cross the threshold level, even with a dead calm on the ground.

Carl
KM1H

[AJ1G]

Wow!!!  Are those bad boys visible from Route 2? 

[KM1H]

Sure looks solid Tom. Did you get that fiberglass rod idea from Chuck or vice versa?  He used that material when the 3 el 80 got rebuilt before I bought it.

Finally decided it was too much for this location so it and the 200' of BCB tower I had (similar to Rohn 65) went to 9 land.

I used similar plates and mounting on the stack of 4 el 20 which were on 40' x 3" booms. No amount or wind or ice ever fazed them. I used a radical taper schedule going from 1 1/4 to 1/2" and it rode like a bird in the wind and the ice just slid off. Probably nothing that Leeson would agree with but I never bothered buying it either The first pair were built long before he wrote it so I was confident. Almost 25 years of surviving for them but the high ones were tough on rotators at this QTH as was the 40M on the mast. The 20's are now a pair of 3 el on 20' booms which even a Ham M series can handle on the sidearms.

At the prior QTH which was in a bowl surrounded by hills (Im on top of the biggest one now) I had just a single 4 el 40M KLM at 140' and the winds were generally calm except when Gloria came thru and everything survived.

The things we go thru to kick ass with a better signal.  

Carl
KM1H

[Steve - WB3HUZ]

STRAPPING!

Yaz is 6 already. Sheesh. I am getting old. Seem like just a few years ago that I visited and you had just got him as a pup.

[K1JJ]

Carl,

I've used fiberglass centers for a long time now. The 10-20M log periodic used them for every element. It sure is a better technique than those Teflon inserts that KLM used for Chuck's 3el 75M Yagi.

I remember almost buying that Yagi from you back in the early 90's. I didn't know you had a big tower to go wid it too. I don't expect to ever put up another 75M rotary Yagi again. I like the wire delta loops for longevity. Seems no one can keep up a rotary for long on 75M.  There's a ham up in NH that has one at 190'?   He has the XX crew work on it and I think it's been up and down the tower at least three times now. Haven't heard him on in a coupla years with it. It was a rotating tower.  40M rotary Yagis are the limit for me.

FB on the 6M 16el Cushcrafts. How long were the booms and how heavy were they?    Two years ago I built up a 6M Yagi with a 110' boom. It was absolutely huge. I wanted to turn it wid my prop pitch. But after building it I realized it was just too damn big for one guy to handle, so I recycled it into other antennas.  Soylent Green antennas.

That's amazing how the wind hits a mechanical resonace and amplifies itself at your QTH, so to speak. Makes sense, just like water can be made to increase pressure and speed by being forced through a smaller opening.

Well, tomorrow I raise the last 40M Yagi to complete the raising. It’s all set up and ready to go in the morning. Then it's time to connect them all up and do some testing.  Oughta be fun holding court into EU.

BTW, also got the 75M delta loops working FB. They are switchable NE/SW using relays and 142 degree coax stubs on each element. The reflector connects to an 11uh coil while the other is directly fed. Then the relays switch it over to reverse directions. Huz uses a similar system on 40M as well as Matt/XX for his 75M deltas.  The f-b is about 25db.


Chris/AJ1G:  No they can't be seen from Rt2, but can be seen from the next few set of hills. Rt2 is in a valley and too close to the QTH.

Steve:  Yeah, Yaz is in his prime "good guy" phase. I've always thought it takes about 5 years to train a dog until he is about perfect. Then the next 8 years or so is bliss. They know all your habits and you theirs. They aim to please and cause little trouble.  Yep, Yaz is a good guy now and deserves a big party this weekend. Bring Shasha and let’s dog party like it’s 1999, caw mawn.

Later -

T

[KM1H]

Yeah, no more crazy antennas for me Tom.

The 6M CC's are on 4' booms, this is a collinear just like the old 2M ones of the 60's. Each bay is a full wave reflector and a full wave DE insulated and fed in the middle. That equals 4 el. Each bay is 1/2 wave spaced. I will setup to select each 16 el group or all 32. It has a wide elevation lobe as well as a huge azimuth lobe. Great for aurora and meteors plus contesting. I'll probably have the 20 el yagi array switched in also or maybe use one amp for the collinears and another for the yagis....at the same time. The gain should be impressive

Carl
KM1H