The History of The Cubical Quad Antenna for Ham Radio

The story of how the Cubical Quad antenna came into being is a fascinating one. It was created out of necessity following an emergency call for help from radio station HCJB back in the early 1940s. HCJB was located high on the mountains of Ecuador. Their new upgraded 10Kw transmitter was literally setting their antenna system on fire. As a result, this Christian radio station (in the words of W9LZX) "received divine intervention. This "intervention" heralded the birth of a new and unique antenna. It was given the title of "Cubical Quad," and the word spread quickly among the Ham Radio community. Was it a genuine antenna with amazing gain or simply a hoax?
We take a look at how this antenna was conceived and developed.
00:00 - Opening
00:53 - The Birth Place
01:27 - The Power Increase
02:18 - How the antenna began to nelt and catch fire.
04:58 - The Emergency Call.
-5:50 - The Concept of the New Antenna.
06"40 - The Loop is born.
07:26 - Would this new design work?
08:09 - Ham operators test it out
08:40 - How much gain and F/B ratio?
11:28 - Feeding the Antenna
12:30 - Angle of radiation.
13:56 - The physical structure.
17:03 - Multiband design
19:08 - Dimensions
19:52 - The Mini Quad
22:43 - Is it worth the effort?

[@norbertstepien9185]

I operated with a 5 band cubical quad in the 90's and it was the best antenna I've ever experienced. It is an imposing structure and I had to abandon it when I moved from my QTH, but I hold fond memories of its unrivaled performance.

[@watersstanton]

Thanks for the info.

[@mikesmith5139]

Hi Peter. A brilliant video. Thanks! I vaguely remember the story of the cubical quad at HCJB, so it is so very good to watch your excellent presentation which filled in all the details. When I had my first 'proper' shortwave receiver, back in the early 1980's, HCJB - Herald Christ Jesus Blessings - was one of the stations that I initially received. I listened regularly. The station even sent me an HCJB pennant when I submitted a reception report. Happy days! Thanks again Peter. 73, Mike M0MTJ

[@g0fvt]

Thank you Peter for the more complete history, I had not heard about the actual noise nuisance of the corona discharge before. In the early 1970s a friend and I pestered my father (A G3) for the dimensions for a band 2 3 element quad. We made one from scrap aluminium extrusion from double glazing and bits retrieved from old band 1 TV aerials. Absolutely stunning results, we had no means to produce scientific data but we did find we could null out local VHF stations to listen to more distant ones. Later on my father did build a 6 element cubical quad for 2m, a very light and compact antenna. 73

[@watersstanton]

Thanks for sharing - very interesting.

[@dandypoint]

You must have the same book I do! All About Cubical Quad Antennas by William I Orr W6SAI ! Great book. I have worked a bit with Quads with several friends. One was a full size 4 element tri band 20/15/10 meter monster at 60 feet. Worked good but it was replaced with mono band Yagis eventually. Another was a fixed 40 meter quad hanging from trees. Worked good but was eventually replaced with a Yagi. I built and used several Quagi antennas for UHF satellite work some years ago. Quad reflector, Quad driven element with 5 or 12 Yagi type directors. The 7 element Quagi worked good but the 14 element version was too directive and I had a hard time keeping it aimed at the satellite! I presently have a 2 meter two element quad in my garage to work the local repeaters. I have also used it for ISS APRS work. The Quad is safer than a Yagi when handling as you won’t poke your eye out! I explain a quad element as being two halfwave dipoles spaced 1/4 wave apart. With the ends of the top one bent down and the bottom one bent up to touch the top one. Gain has to be less than the two straight dipoles spaced at 1/4 wave, thus the approximate 1 dB figure. I personally think the quad being quieter than the Yagi is a myth. Noise is electromagnetic radiation and there is no reason a good antenna would or could discriminate between noise and desired signal except due to directivity.

[@watersstanton]

Many thanks. Interesting content. 73 Peter

[@jacianmcgurk7424]

I still get some noise on mine when it rains hard which has been a lot recently lol. Great video Peter Cheers

[@johnallsopp8260]

Very interesting Peter, similar to ST Elmo,s fire 73 de John G4YDM

[@watersstanton]

Many thanks John.

[@ZAR797]

Very interesting history of this antenna. Thanks from South Africa

[@fnordist]

What's particularly interesting is that when multiple quad elements are excited with different phases, it's possible to generate even higher forward-to-backward ratios and less sidelobes. e.g 1/4wl apart, 84 and 71 degree phasing lines. 6el quad ( reflector, phase 84, 1/4wl space, - phase 71 - director 1, director 2, director 3. Provides about 4 dB more gain than a standard quad.

[@watersstanton]

Sounds like a mechanical challenge for HF, but interesting.

[@fnordist]

@@watersstanton This can be achieved using five booms, with four placed around the perimeter and one in the center, all supported by crossbeams.

[@adzbasslines268]

I could just imagine 1kW of power at close proximity (frequency depentant) could keep him warmed from the inside out on his motorcycle in winter time :P

[@wshanney]

I had a triband quad around 1990 at 45'. It replaced a triband Yagi. It had about the same gain but it was very quiet and had terrific front-to-side isolation...W6QR

[@watersstanton]

Many thanks. Seems to be the general opinion.

[@darbymathis7670]

So much information/wisdom given, enjoy your videos so much. Always causes me to think and reason when i see your presentations. Thank you for what your do!! I've built some quads for VHF portable ops...much fun. God bless, 73 WD9M

[@watersstanton]

Wow, thank you! 73 Peter

[@AlexejSvirid]

The problem is Devil runs the world. He is lier and murderer. This is the reason why Hitler got the power, but Christ was executed as "blasphemer" and "rioter" by denunciation of clergy. This is the reason why the whole world is Sodom. That's why we've got the Gospel about the God's kingdom. Jehovah would put everything in order. The dead will be resurected and we'll meet our loved ones again! :-)

[@robertallbright]

Another good one Peter Thankyou 73 Robert G3RCE

[@watersstanton]

Cheers Robert.

[@davidwalle5025]

Good job Peter

[@ralfkruse7565]

Thank you, Peter. Long ago, still in Germany, my Neighbur had built a 3 band Quad, but when it worked, it was fine, but after heavy storms, he had always to repair it. So he changed to a Yagi. No more repairs were needed. If you have another interesting story about horizontal quadloops for 160m, please tell it. F1VEL ex DB3YZ

[@watersstanton]

Many thanks. Yes storms can be a problem for Quads.

[@raylowe3324]

Very nice history of the quad. Back in the 1970's N6NB built an antenna featured in QST magazine called the Quagi for VHF and UHF. It had a quad driven element and reflector . All of the directors were yagi elements. The antennas when stacked made a decent moonbounce array.

[@watersstanton]

Thanks for sharing

[@chrille2409]

I'm currently operating a two element Cubical Quad for the 10m Band, and i must say it's the best antenna I've ever had for this band. I think it's especially interesting for nowadays operation, because it's very, very resistant to local QRM. So reception- wise i would always prefer a quad over a yagi.

[@watersstanton]

Thanks for sharing

[@brianfields4479]

Thanks for sharing Peter, yet again, so very interesting. 73 zl3xdj.

[@watersstanton]

Thanks Brian. 73 Peter

[@eddiehatherall2154]

Thank you Peter another very informative video GW6BXU

[@watersstanton]

My pleasure!

[@AlexejSvirid]

There is a typo in the video's name.

[@frankedwardcurry]

I remember listening to Radio HCJB on Shortwave back in the eighties - (Hail Christ Jesus Blessing) I believe it stood for - I used to like their DX Party Line program - Ooh Happy Memories ! 73 from Frank M3 FEC. Happy Memories of

[@watersstanton]

Many thanks Frank. Interesting to hear the origin of HCJB. 73 Peter

[@filipinotuvera]

Learn about it.