I was itching to make another antenna and someone mentioned the NorCal Doublet. K7WXW graciously sent me some ribbon cable and I got to work. This is an easy to build, solder-less tunable dipole style antenna. It tunes 10-40 meters great. Instructions here: http://norcalqrp.org/norcaldoublet.htm 73 de Tim N7KOM
The Norcal doublet is a great antenna for portable operation! I built one from some ribbon cable I purchased at the Dayton Hamvention a number of years ago and keep in in my portable kit. I also have the same design built with more traditional wire and balanced line for when I want to put something a bit 'sturdier' in the air. I just want to add a couple of points. Antenna guru L. B. Cebik W4RNL (SK) stated that the 44' doublet was one of his favorite antennas - going so far to say that if he could have only one wire antenna that would be it. The reason he liked it was because its broadside radiation pattern is very similar on all bands 40-10 meters. That particular length also happens to make it an extended double Zepp on 10 meters. The article at the first link below describes the antenna in detail. He also modeled it turned on its side as a vertical dipole and discovered that it has a low radiation angle on those same bands so it would be a decent DX antenna in that configuration (see the second link below). It's small enough to be a handy portable antenna, and if a person has limited space at home, a 44' doublet built with standard copper wire and window or ladder line can be an excellent solution for 40-10 meters! One of the takeaways from this project should that non-resonant antennas fed with balanced line can actually outperform their resonant cousins. If you tend to use only resonant dipoles fed with coax cable, you're missing out on some very efficient (and often higher-performance) antenna designs. http://www.antentop.org/w4rnl.001/aledz.html http://on5au.be/content/gup/gup39.h...rk-yMWrWWDobcVn28_qrLGmL5zF0ZkB25Ff1iNvpYTWmg
Ladder line is. But computer-ribbon cable with its PVC insulation and two unused conductors in the middle adding capacity hardly is. There is a good reason for the "air" in ladder line, whether it is home made or Wireman. A doublet with ladder line works because the ladder line copes with high VSWR due to its low losses. I wouldn't be surprised if using this computer wire simply melts at certain frequencies and a reasonable amount of power.
It's good stuff! If you want something easier to find these days than ribbon cable, I can heartily recommend a 50' ethernet cable: you can make four! Untwisting 22' is probably a bit harder than unzipping 22', though.
Nice experiment. Seems to be a another kind of a Bazooka-Antenna. The magic is in the fine tangle of wire. I tried something like that with a copperline with 60 veins and a diameter of 0,1 mm each. Here I build a 80M 1/2 wave helical. It worked as fine like the computercable, to that a phonic transmission wasnt a problem too. So a tuner is recommended. But dont try to be more than to be a QRP.
Ladder line is awesome. I love it. I ran a 34x34 doublet for 5 years. Had it 5 stories high mounted on 12m fiberglass poles above that. Miss that setup. Was insane off of the ends on 15m, too.
A higher-power equivalent is simply a 44' doublet (22' on each side) fed with balanced line. I built one using some spare wire and 450 ohm window line along with a center tee and end insulators that I purchased from DX Engineering.
