Unfortunately many of the old images have been lost.
I did dig up this from the links in the thread.
73
Jeff
I did dig up this from the links in the thread.
73
Jeff
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Here is a intetesting Antenna to think about
- Thread starter AudioShockwav
- Start date
I like to think of the DDRR antenna as half of a slot antenna with the end left open to account for the missing quarter wavelength (otherwise the feed point impedance would skyrocket being a shorted quarter wave stub). Maybe that explains the vertical polarization.
It wasn't the DDRR that I was analyzing the vertical polarization models show, it was the Super Sinner, and later a dipole antenna mounted horizontally in the modeling software. The DDRR will definitely have a vertical component.
The DB
DB, I bumped the thread here because Shadetree was looking for info on the DDRR and there used to be some good links in this thread.
Thanks for your input on this thread.
73
Jeff
Just for information, here is John's latest DDRR like the one on his Jeep in his video.
This one is square, not round, he has said that it makes no difference between round and square.
73
Jeff
This one is square, not round, he has said that it makes no difference between round and square.
73
Jeff
I don't know, I have zero experience with these antennas, I know he was running one on his jeep, that was the one posted on YouTube.
This is work in progress, if I hear more I will update.
73
Jeff
Thanks Jeff, I saw his post on Facebook and asked the same question. I will update here when he replies.
Thanks,
Chris
I am going to build this, perhaps today even as I dont feel like working on this HG box right now. I have a 32x20 lean-to with a metal roof that connects to my Radio shack.
The first test was to far off, tuned at 29.7. It was just a quick and dirty test, I just poked 6 gauge though some boxes and grounded it to the tin roof. Now I am directly in the Texas sun so I called it quits until Friday when I have free morning time. Anyway, its a working antenna as far as the analyzer goes. I cut it at about 110 inches do I had room to work with.
He replied that a small adjustment on the tuning cap is all that was needed.
I have wanted to build one of these for quite a long time, but haven't. Now I no longer have an SUV... but I one day may find some time and scratch the itch.
Awesome!!!! I thought mine needed to be closer to the tin roof and not 12 inches away. I have not got to revisit this yet as I had some amps that came in for repair but I will get back to it and let y'all know. Thank you shockwave for this info, that helps for sure. I have the Rig expert AA-650 zoom to take a lot of guess work out antenna building but pics like this are golden. I will add a variable air cap to my next attempt to be sure I have all my bases covered.
Air variable? Running barefoot? John said a 15kV vacuum variable barely handles an 8-pill, not sure air is the way to go there.