Excellent explanation of the OCFD, my main QTH antenna. At school, the x-axis went left to right, and the y-axis went up and down. I'm in the UK. Thank you for the presentation.
Dear sir, thank you for this video. I have been very interested in OCF antennas, making them in particular. Your presentation was helpful. It is embarrassing that the ham world has its share of negative commenters. Please ignore their sad efforts. Best wishes from S.E.Tennessee, 73 KQ4IXD
At 9min 45 seconds: I think the capacitor is to bring resonance up in frequency a bit on 40m; I've used this technique to good effect on other OCFs. The capacitor is at or near the current anti-node on the lowest frequency. Because of its position and value, it is almost negligible on harmonic frequencies.
It's "Common Mode Current", not common current that flows on the outside of the shield. Then there is differential mode current that flows on the center conductor and the inside of the shield.
Like Ted, I'm a big fan of OCFDs. I'm often asked to help other hams with theirs. And I've abandoned the 1/3-2/3 split long ago. Anyway, I'm always surprised at how many hams not familiar with how an OCFD works that think they can trim 40 meters by adjusting length of the long wire, and adjust 20 meters by adjusting the shorter wire. This is NOT how an OCFD works, you can not adjust bands individually like with a fan dipole.
Anybody? I'm tripping over the terminology "Balun vs Unun" when it comes to OCF's. This video @11:25 shows a Summary reprint of a 1988 QST article on OCF's and the transformer is identified as a "4:1 current balun". I learned to respect without question the tech stuff in QST but is their use of the word "Balun" is a poor choice of words or am I mistaken? I'm in the midst of an OCF install. My wire is up but my 4:1 Balun /CMC choke combo (copied from TRX labs on RUclips) complete. swr's bad when up in the sky. On the bench with 200 ohm it's wonderfully flat 10-40m. Should I rewind the balun section of the TRX Lab's design to be a proper 4:1 Unun?
![[DRAGON BALL LEGENDS REVEALS ＆ STUFF] LEGENDS FESTIVAL 2024 Special Edition Part 1](http://i.ytimg.com/vi/mV5bGIswTtQ/mqdefault.jpg)
Ignore the trolls. Great video. Thanks for posting. You are an excellent speaker. I'm glad I watched!
73, N4MJR
Excellent explanation of the OCFD, my main QTH antenna.
At school, the x-axis went left to right, and the y-axis went up and down. I'm in the UK.
Thank you for the presentation.
Excellent talk!
Dear sir, thank you for this video. I have been very interested in OCF antennas, making them in particular. Your presentation was helpful. It is embarrassing that the ham world has its share of negative commenters. Please ignore their sad efforts. Best wishes from S.E.Tennessee, 73 KQ4IXD
Like the talk. I learn so much that I might need to make one of these…
At 9min 45 seconds: I think the capacitor is to bring resonance up in frequency a bit on 40m; I've used this technique to good effect on other OCFs. The capacitor is at or near the current anti-node on the lowest frequency. Because of its position and value, it is almost negligible on harmonic frequencies.
Very good presentation
It's "Common Mode Current", not common current that flows on the outside of the shield. Then there is differential mode current that flows on the center conductor and the inside of the shield.
Common Mode Current "is" RF current flowing on the outside of the shield.
Then make your own video and grace us with your superior knowledge.
Like Ted, I'm a big fan of OCFDs. I'm often asked to help other hams with theirs. And I've abandoned the 1/3-2/3 split long ago. Anyway, I'm always surprised at how many hams not familiar with how an OCFD works that think they can trim 40 meters by adjusting length of the long wire, and adjust 20 meters by adjusting the shorter wire. This is NOT how an OCFD works, you can not adjust bands individually like with a fan dipole.
Anybody? I'm tripping over the terminology "Balun vs Unun" when it comes to OCF's. This video @11:25 shows a Summary reprint of a 1988 QST article on OCF's and the transformer is identified as a "4:1 current balun". I learned to respect without question the tech stuff in QST but is their use of the word "Balun" is a poor choice of words or am I mistaken? I'm in the midst of an OCF install. My wire is up but my 4:1 Balun /CMC choke combo (copied from TRX labs on RUclips) complete. swr's bad when up in the sky. On the bench with 200 ohm it's wonderfully flat 10-40m. Should I rewind the balun section of the TRX Lab's design to be a proper 4:1 Unun?
Are these in Magnetic or True for 45 degrees and 150 degrees?
Your azimuth is not the same as his location. The map is on the internet. It is very enlightening.
Dx at 30 degrees? Ok there bud.