2 Element Quad Construction

[KDDL]

Very interesting project. Will follow it

[Island_0860]

More news..

My shipment of RG-8 wont be available this week ..looks like thursday of next week when everything should clear customs.

The weather has been un-cooperative here now...seems that afternoon t-storms are the norm ..so I will have to work quick and start at daybreak on the weekends.

The lack of cable isn't a real setback ..as there is still PLENTY to do.

Tommorow i will be checking out whats available for mast pipe..and decide on just whats going to get welded below for the boom to mast connection (This was SUPPOSED to have gotten completed on MONDAY).

The pics below show whats been done so far ..at least the wodden A- frames are DONE





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[Nagant]

It's looking really good. You sure are making great progress with it.

[Island_0860]

Update.

Since there is no ready made telescoping mast to be found and tower sections are $$$... I'm going with a fabricated mast system.

Bought 20 ft of 2"" OD and another 20 ft section of 1 1/2 " Steel tube for the telescoping mast

It's off this afternoon to the welders...here is what needs to get done.

The mast tube will get welded to the boom ..along with some supporting nuts on to the hubs to secure them to the boom .
Some welding material will be added to the inside of the mast to boom pipe..to help further stablize the union .


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[108dt206]

lookin good m8..can`t wait to see the finished product up and running...all the best m8

barry

[Island_0860]

Thanks Barry !

Who knows how much more is left

All the major welding is completed .
Just need to fabricate some wall to mast stabilizing mounts for the 2" OD pipe

Here are pics of the completed Hubs and Boom


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[drdx]

Man, that thing looks like it will be built like a tank. What are you using for a rotator?

On the wire stretching, isn't there a way to "bake" wire so it is more tempered or something to prevent stretch, or is that just some cb mythology? I'm no metalurgist or however it is spelled but stretching can be an issue on long runs. In your case I'm not sure it would come into play.

-drdx

[Island_0860]

Hey Doc..

Yes i'm going to probably get around to wire stretch operation on Sunday.

Its gonna be 2 pieces of 8 gauge pure copper wire each rough cut to 39 FT lengths...and i plan to stretch them out at the same time

Checkout the pic... the wire can support itself..that is a 5 FT piece standing on its own

Need to check with Gunny... to see if that wire could withstand 12W PEP

Dont know how much more fun awaits me when I thread the wire thru the spreaders.....I'm thinking HomerBB is grinning now....))

Its built heavy duty yep ..but i'm out of options as the most common material available is steel.

Total weight is not that bad..feels like 40 lbs



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[drdx]

I'm not sure if you've thought of it, but that longer wire may tune a little lower than thinner #14. You may need to shorten your length a bit to account for that so it behaves as you like. If the parasitic element is a reflector you will be fine as it may just appear electrically a little long. If using it as a director it could be a tad too long if you're not careful, as #8 is some large wire for a quad. I love it.

How will you fine tune it? Without an analyzer, you could just feed each element and tune to resonance, then make the reflector 5% longer or whatever your formula dictates and be close, or feed the reflector and tune it to a lower frequency below band so it exhibits the right qualities. They behave a little differently in the air vs. the ground too, but that can all be sorted out.

-drdx

[HomerBB]

WHen I was tuning mine I asked questions about the 5% thing. The answers were universally the same. Tune my driver to best SWR (I had no analyzer) on the band of choice, and then make the physical length of the reflector 5% longer. I specifically asked if tuning the reflector to a given frequency would be better 5% longer method, no stubs or other matching devices on the reflector. Just cut it and mounted it.

[Island_0860]

Yes Homer.. I found the same answers..and probably like you I have 20 Quad bookmarked sites and a 50 meg private Quad folder.

Doctor..you bring up an excellent point about the element wire diameter vs length.
There is an outstanding . PDF on this very subject called "Rethinking the quad beam" by L.B Cebik ..which WONT put you to sleep !

Have a number of outstanding books on Antenna design and Fundamentals ...but I go off to sleep after 5 mins ..but in reading this PDF I could follow right along

Here is the D/L link to the PDF :

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[626]

Need to check with Gunny... to see if that wire could withstand 12W PEP

You got the go ahead man. Heck Im thinking 1200W would be fine. You got the GUNNY "overkill" seal of approval.

[Island_0860]

It's been awhile since the last update.

I had all kind of troubles finding these 2 inch steel couplings locally
The only ones that I have came with the pipe.
Anyway its off to the big city tomorrow to pick up 3 more of these.
I'm finally all cleared with local customs..so I get to pickup my radio with the 150ft run of RG-8...no point in making 2 seperate 7 hour trips.

My plan is to cut the couplings in half and use those as the basis of the wall to mast connection.
I like the threads on the couplings ....they will dig in to the mast pipe providing a good grip.

More tomorrow and this weekend as things begin to take shape

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[HomerBB]

Good deal. We'll be watching.

[Slim Pickins]

Looking good. I dunno though, 12w may be pushing it on thet wire

Slim

[Island_0860]

Finally got the coax and radio in from the U.S last week ...all is OK so far.

Picked up the GUNNY approved customized steel Wall to Mast support from the shop today.

It was designed from Channel Master's mast to wall mount (on the far left in the picture) ...just added some beef to accomadater the 2 inch mast pipe.

On the far right is the 2 inch steel couplings that were cut in half to form the Mast supports.

The boom is getting its mast tube welded with some outside support nuts ..and I'll post some pics of that tomorrow.


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[626]

I appreciate your desire to go heavy duty. I really do. The only concern I have is if it will weigh too much.

[drdx]

Well, from his location, if he's big on North American action, it only needs about a 90 degree span. That 2 element can almost slice that down the middle, but I too wondered on the weight issue. If I had his roof and was thrifty I'd spend all of my money on coax and make separate directional arrays, all switched, and call it a day, no moving parts involved, but the quads are Qool with a capital Q. <-- original word alert

-drdx

[Island_0860]

Got the boom fully completed ..the hex bolts now welded to the mast support pipe as seen in the picture.
Going to have to grind down inside the boom mast tube, because as it is its too snug of a fit.
Thats easily doable by myself with a drill and stone.

In the final pic of the boom with the hubs..I'm showing them spaced out about 6.5 feet which should provide ample space to move them in and out ( which I imagine i'll be doing a LOT of)

Most of the references suggest a starting point of 5.3 feet between reflector and driven.

Hey GUNNY...I did a weigh in ...and im seeing around 14 pounds for the 8 foot boom with the hubs attached...keep in mind i will be cutting off close to 2 feet of boom after adjustments

Estimating the final complete assy to weigh 16 pounds, not too bad for all steel construction
Dont understand where I originally got 40 from ...oh well.. :p

Doctor DX nailed it ..ill be pointing it to the U.S ...as there is nothing interesting to me South North or to the East for now....unless KDDL starts getting conditions in Norway

The rotor will be armstrong type.


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[KDDL]

Are you gonna use muscle rotor?

[drdx]

Hey man, that outcome is way lighter than I'd ever imagine.

How big is that roof of yours? Maybe it is the pic but it looks huge, I'm jealous. You could take some wire, some support material, and make a boomless wire yagi aimed in a general european direction for really cheap, using wire elements, supported at the end by simple supports, just like your dipole in the pic but with a reflector and director(s) and really boom into a target area. A beam like that of 4,5,6,7 elements or whatever you have the length for would certainly wake the band up earlier than the quad might to the east.

-drdx

[2J-FJ]

Wow, this thing is QUALITY! I bow to your skills.

For sometime now, I've wanted to build something just like this!!! Awesome!!