Discussion in 'Antennas, Feedlines, Towers & Rotors' started by KF5LJW, Apr 12, 2015.
What he said. Or a 20-meter half-wave center fed with a balanced line.
I run a OCF Dipole here. It is homebrew and it worked well with a cheap RadioWave 4:1 balun, but I had to use the tuner on all bands and 1 wasn't usable (15M? 17M? , I can't remember which). I switched to a 2 core Gnuella Balun and haven't needed the tuner since. It is a amazing antena and I am very happy with it. Yes, it is a $100 Balun, but it was worth every penny: http://www.balundesigns.com/model-4115ocf-4-1-for-ocf-dipoles-1-5-54-mhz-5kw/
What dimensions are you running?
Mine is cut for 80M. It is 45 feet on one end and 90 feet on the other. Fed by LMR-400 into the balun.
I used to have a G5RV half size, it was rubbish compared to the off centre fed dipole I have made myself. and I get all the bands except 17 that run without the tuner...That means i can hop from one band to another and call cq flip vfo's A/B listen to that other dx station to see if he has finished or go back and call cq again..I don't do contests but if I did the tuner would be the first thing I would throw out..
I have made my own balun ( double ferrite current balun ) and feed mine with 25 meters of 75 ohm 11mm coax. The wire 1mm is almost invisible, and it's giving me fantastic results..The G5RV was fine with valve radios and could be tuned in using the tank circuit of the valve output, but for modern transistor radios, and amplifiers, i would go with the OCFD and even if you pay 100$ for a balun....though they are easy to make...so why buy one ?? and in ma last 15 contacts 14 were different countries..never got that from a G5RV..
Another option might be a half size ZS6BKW, with a center fed 46 ft flat top and 21 feet of "450" ohm window line. Looks like a pretty good compromise for 40/20/10--good SWR on 20/10 SSB, and while you will need a tuner for 40, it is likely that your signal will be pretty decent for 40 SSB--especially considering the small size of the antenna.
And, if you have a target area and antenna supports in the right locations, all three bands have their main lobe in the same direction. This antenna would be quite useful in New England when pointed at Europe. A difficulty with larger antennas is that the main lobe splits, so your antenna no longer points in the same direction as on the lower bands. I have worked a lot of Europeans with 100 watts and a dipole. I could do this with a half size G5RV or ZS6BKW on 40/20/10, but not the full size versions.
Correction, even a half size G5RV is too long at 51 ft for 10 meters to have a main lobe like the lower bands.
44 ft would be ideal for 10M in terms of gain and pattern--changing to 45 feet of insulated wire would make the pattern a little better on 10 while being a better compromise for impedance on the three bands.
Please re-read the thread. Nobody said a G5RV or a G5RVjr would not work well on 15m. A ZS6BKW, which is a variant of the G5RV family, will not work well on 15m.
Here's a scan of my 160m OCF (163x80 IIRC) in ORANGE vs my full size G5RV in RED.
An even better choice might be the 44' long version for 40-10M on the same website.