QUAD ANTENNA HELP

[unit_399]

I'm trying to put together a 3-element Quad. I am using #12 enameled wire for the driven element. Do I have to use the same diameter wire for the reflector and director, or can I use something smaller, say # 18 or so??? I'm not trying to be a cheap-ass, I just want to save on the weight as much as possible. Logically, I think the smaller wire would be OK, but I'm no antenna guru. So... can anyone help me out on this?? Thanks.

- 399

 

[RickC.]

It'll be OK. I've used 14 ga on most of the quads and delta loops I've built, but did build one from 17 ga electric fence wire once.

Good luck, and post pics.


Rick

 

[shoemaker]

HELLO UNIT 399, I AM A QUAD JUNKIE AND I HAVE DESIGN SEVERAL QUAD ANTENNAS. THE ANTENNA IM USING NOW IS A 4 ELEMENT ON 30FT BOOM, YES ITS AN OPTIMIZE QUAD. ALL THE ELEMENTS ARE #12 SOLID COPPER WIRE, THIS IS THE OUTCOME: 16.55DBI, F/B31, SWR1.1, 50.2 OHMS. IF U ARE INTERESTED IN SOME SPECS LET ME KNOW.

 

[packrat]

I for one would be interested in the details of your quad. I have been thinking about one for a while now.

Thanks,

PR

 

[Captain Kilowatt]

HELLO UNIT 399, I AM A QUAD JUNKIE AND I HAVE DESIGN SEVERAL QUAD ANTENNAS. THE ANTENNA IM USING NOW IS A 4 ELEMENT ON 30FT BOOM, YES ITS AN OPTIMIZE QUAD. ALL THE ELEMENTS ARE #12 SOLID COPPER WIRE, THIS IS THE OUTCOME: 16.55DBI, F/B31, SWR1.1, 50.2 OHMS. IF U ARE INTERESTED IN SOME SPECS LET ME KNOW.

Optimized for what? Bandwidth? Forward gain? F/B ratio? It can't happen for everything at the same time hence optimizing can only be done for one of those factors. Not sure I would want to use solid wire.Several guys have had the wire break after repeated flexing in the wind. My B I G project next year is a five band quad for HF with two elements on 15,17 and 20m and three elements on 12 and 10m.

 

[packrat]

WOW. How long will the boom be???

 

[RickC.]

Optimized for what? Bandwidth? Forward gain? F/B ratio? It can't happen for everything at the same time hence optimizing can only be done for one of those factors. .

My questions as well, though I wasn't going to weigh in on it. I'd be careful of quoting exact gain figures without a way to accurately measure them. 4 elements on a 30' boom is 10' between elements-- for what band is this?

That aside, post pics, I'd like to see your work!

Rick

 

[RickC.]

For anyone who wants to build a quad for any band, three words:
Buy This Book:

I payed 7 bucks for this copy, used, online, a couple of years ago. It replaced a copy I'd had back in the 70s that was a victim of several moves. This was written long before EZNEC and the MFJ-259, and is a great resource and is easy to read with piles of good photos and diagrams- and plans. If nothing else, it proves to the newer crowd that very effective antennas can be built without the aid of computers and $275 analyzers.

You're welcome.


Rick

 

[HiDef]

Bill Orr was great.

 

[Captain Kilowatt]

WOW. How long will the boom be???

Not that long actually.A typical two element quad for 20m has a boom length around 8-10 feet.The third element for 10-12m simply mounts in the center between the two 20m elements. I have a heavy duty boom that is 14 feet long so I will experiment a bit. The quad spreaders will be about 26 feet long tip to tip or 13 feet from center of the boom to the tip +/- a few inches. I plan to design and build for a windy and ice laden area. Max Gain Systems in Marietta Georgia is going to love me.

MAX-GAIN SYSTEMS, INC. -- FIBERGLASS QUAD SPREADERS

 

[C2]

if not solid wire, what would you use?

copper clad steel?

 

[shoemaker]

GE RICK C, I OWN A COPY OF THAT BOOK, ALSO ALL 3 EDITIONS OF THE QUADS NOTES WRITTEN BY L.B CEBIK W4RNL AND BOUGHT ALL THE QUAD SPEC FROM ANTENNA X DONE THROUGH EZNEC. MY QUAD WAS OPTIMIZE FOR FORWARD GAIN, F/B GUT OF COURSE THERE WAS THE OBVIOUS SACRIFICE BANDWITH. I ONLY DESIGN IT FOR ON CHANNEL (27.025) SO IT DOES NOT MATTER AND THE ANTENNA PERFORMACE IS EXCELLENT. THE EZNEC.4 PROGRAMME IS REAL GOOD. ANYMORE QUESTION ILL BE HAPPY TO ASK.

 

[RickC.]

Fair enough Shoemaker, it sounds like you've done your due diligence. 30 feet is a whopping boom for a 4 el 27 MHz quad! Just curious, how wide (KHz) is the 2:1 VSWR bandwidth?

(turn the caps lock off, you'll be easier to read) ; )


Rick

 

[Captain Kilowatt]

if not solid wire, what would you use?

copper clad steel?

You could use the flexweave stuff if you can afford it but I plan to use #12 stranded copper wire. I will prestretch the wire first so it will not detune over time. I have a full spool of #14 and a full spool of #12 with each spool containing 300meters (+/- 1000 feet)



Flexweave wire:

http://www.eham.net/data/reviews/images/4327.jpeg

 

[C2]

I guess stranded will hold up longer, but it's still just a bundle of solid pieces.

I had not heard of Flexweave.

I guess I just take it for granted that I live in a mild climate.