Big JA 80/40 M beam with 'wing boom'...interesting...

[W1VD]

Not sure if this has been posted here before...

JO1DZA 'folding wing boom' 80/40 meter beam:

http://www.youtube.com/watch?gl=JP&hl=ja&v=23YjF7Wcplc

Other interesting stuff...look up JO1DZA on QRZ.com.


(tnx W1ATT for info)

[Todd, KA1KAQ]

Yeowsers! That's some serious metal in the air, on many levels (no pun intended). Seems like it would minimize the possibility of damage during, say....wind or ice storms. Something for 'JJ to try when he feels like tinkering. 

[K1JJ]

When I look at that video, I wonder how Japan ever lost the war...   Those people are so industrious and innovative with the resources they have.

I've worked DZA before on 75M long path. ("long pass" as he calls it)   It's not easy and usually requires Yagis on both ends unless condix are exceptional.

I notice he used the folding boom on his smaller Yagis too. That is quite a good method to access all elements when repairs are needed, rather than taking down the beam. Though, the complexity and wind load is increased.

Those guys have to be in great shape to maintain that complex set of towers, for sure.  (old buzzards need not apply)

T

[W3RSW]

Tom. yeah, it is funny. The Japanese are quite the dedicated artisans and techies.

Japan built up for a short war, knock-out punches and swift victories, knowing that the US and others were increasingly choking off supplies and oil. 

They, at first, had a "just want to rule the Pacific" mentality, but like any country, man or beast that achieves early victory they didn't know when to stop. ("they" never do.)

Sooner or later everyone, every country has their Waterloo.

As an aside,
joke for the day,

The first cup protector was used in a field hockey game in 1874.
The first helmet was used in 1974.
It took men 100 years to realize they had to protect their brains too.

[W1AEX]

Impressive example of innovation and execution of ideas. This is motivation on a whole different scale. I mean, I might be motivated to mount three 160 meter Isotrons on a 20 foot boom at 30 feet, but I couldn't even imagine carrying out a project like this.

I also couldn't help but notice the almost perfect horizontal alignment of each element on every antenna. Whenever I have put up a beam the elements have always looked like they were aligned by an idiot.

Nice find Jay.

[K1JJ]

I also couldn't help but notice the almost perfect horizontal alignment of each element on every antenna. Whenever I have put up a beam the elements have always looked like they were aligned by an idiot.

     I hear ya, Rob.   Yep, that's why they invented the bubble level.

But, the problem with element to boom alignment is two-fold.  Once you get the element straight, by tightening one side of the u-bolt more than the other side, it rotates the element off again.  It's a juggle back and forth operation. I'm going through that now with my new homebrew triple 40M Yagi stack on the ground.

The second problem is that most commercial Yagis are NOT pinned - the element is not pinned to the boom and will rotate/slip in high winds. Before long it looks like a CB vertical beam shooting skip, caw mawn.   It pays to drill two holes thru the element to boom plate to the boom - and install two 3/8" bolts to keep things solid.   This is in addition to using at least FOUR u-bolts. This can't be stressed enuff when building Yagis bigger than for the 6 meter band - or you will probably see element creep over time.  (element creeps are creepy)

T

[W1AEX]

   I hear ya, Rob.   Yep, that's why they invented the bubble level.

Yup, leveling must be very difficult as the elements get longer Tom, such as with your 40 meter monster. My lame excuse for not using a bubble level is that my tower is a crank-down tilt-over so the elements are not in the correct plane for horizontal alignment since the boom is vertical when it's in the repair or install position. I kinda just take a sketchy guess and hope no one notices...

Speaking of element leveling and alignment, I always wondered about those beams that were mounted on the rooftops of fast food places, banks, and other such establishments, up until about 10 years ago. They looked like 4 or 5 element VHF high beam antennas, but they were always mounted in a diagonal plane. I could never get an answer as to why they were installed like that. Just another mystery of life I guess.

[N3DRB The Derb]

I wonder how Japan ever lost the war...

They wouldnt have. We would have been fighting them another 10 years, and the losses required to make them surrender via conventional warfare would have been unacceptable to the country after 4 years of what they had already been through.

except for this, japan would have at best been a sue for peace deal.  Even with the atomic bomb, there were many in the jap military that wanted to keep fighting. They only stood down when Hirohito decided the price for Japan to continue fighting was too high and ordered the surrender. This act undermined the Army officers to wanted to continue the war and they had to do the Emperor's bidding.

[Bill, KD0HG]

Speaking of element leveling and alignment, I always wondered about those beams that were mounted on the rooftops of fast food places, banks, and other such establishments, up until about 10 years ago. They looked like 4 or 5 element VHF high beam antennas, but they were always mounted in a diagonal plane. I could never get an answer as to why they were installed like that. Just another mystery of life I guess.

Those were FM receive antennas for MUZAK services and the like.
Subcarriers on commercial FM broadcast stations. These days, mood music is delivered by satellite.

Why diagonal? I dunno. I've never seen one installed like that.

[K1JJ]

They wouldnt have. We would have been fighting them another 10 years, and the losses required to make them surrender via conventional warfare would have been unacceptable to the country after 4 years of what they had already been through.

I understand one of the leaders in Japan said something to the effect, "What difference does it make if they destroy us with atomic bombs or continue to burn our cities with incendiary bombs? It's all the same."

After the two a-bombs were dropped, the Russians had just invaded western Japan and were making fast progress cuz of the poor defense in that area. The JA's made a smart decision... do we surrender to the Americans now or hold off and surrender to the Russians? Or just go underground and prolong it?   Looks like they made out pretty well under American occupation.   Can you imagine what it would have been like under Stalin?

But yes, if they wanted to do guerilla tactics on their own mainland, it would have made Iraq look like a cakewalk. Though, they would have also have lost the urge for war for some time to come. Mission accomplished either way.

T

[Bill, KD0HG]

Tom and all:

In 1945, the government procuring agency ordered several hundred thousand Purple Heart medals for use during the Japan campaign that never happened.

Fortunately, they were not needed.

Unused medals from that same batch of Purple Hearts were issued during the Korea, Viet Nam, Iraq and campaigns since then.

Let me add one passing thought: In the late 1940s, Albert Einstein said, "World War 4 is going to be fought with rocks".

[Bill, KD0HG]

Tom and all:

In 1945, at the direction of rhe President, the government procuring agency ordered several hundred thousand Purple Heart medals for use during a Japan invasion campaign that never happened.

Fortunately, they were not needed.

Unused medals from that same batch of Purple Hearts were issued during the Korea, Viet Nam, Iraq and campaigns since then.

Something to ponder: the C squared in Einstein's E=MC2 is an extremely large number. The speed of light, 300,000 m/S squared.

The bomb we dropped on Hiroshima converted a total amount of .7 grams of matter into energy. 700 micrograms.

If we ever invent controlled matter-to-energy conversion a-la Star Trek, we could send a good sized spacecraft to Mars on only a gram or two of fuel.

[Opcom]

I asked on the video site how many Kg of force is required to raise the booms.

[WD8BIL]

Albert Einstein said, "World War 4 is going to be fought with rocks".

At least for our part if this present batch in Washington has anything to do with it.
Our enemies don't care about being ...... "progresssive"!