Author: Kevin Zembower via TowerTalk <towertalk@contesting.com>
Date: Thu, 27 May 2021 16:30:39 +0000
Hello, all, I'm trying to build my first Off-Center Fed Dipole for 40-10M. I'm following the directions at https://www.balundesigns.com/content/OCF%20Antenna.pdf and built the 4:1 balun from the dire
Off-center-fed antennas are a really bad idea for today's world. They are a sitting duck for all of the noise surrounding us, and, by design, they cannot be choked to suppress that noise. Further, fr
I'm trying to build my first Off-Center Fed Dipole for 40-10M. I'm following the directions at If you're looking for multiband, then a "fan dipole" is probably a better bet - it's symmetrical, just n
Since when are properly designed OCFD antennae not resonant? I've used OCFD on multiple bands for years and not noticed any more noise than on similar single-band dipoles. Admittedly, I haven't measu
The statement is: " Stick with RESONANT antennas fed with coax and chokes", not "An OCFD is not resonant"! Antennas not fed symmetrical and choked CAN pickup more local noise. If you donīt have any y
I have three Buckmaster OCF dipoles. I run 1500 watts, so use RF chokes (Palomar MC-1-3000) under the antenna balun and inside the shack at the amplifier. This results in the auto tuner (Palstar HF
Most of them. I've used OCFD on multiple bands for years and not noticed any more noise than on similar single-band dipoles. Did those resonant dipoles have effective chokes at their feedpoint? Admit
If you didn't do side-by-side A-B comparisons then your comment is merely another anecdote. Dave AB7E On 5/27/2021 10:55 AM, John Kemker wrote: I've used OCFD on multiple bands for years and not no
You have been suckered by two incompetent companies. This results in the auto tuner (Palstar HF Auto) being able to tune all bands to close to 1:1 VSWR, allowing full 1500 watts output. Great result
I don't know what to expect in performance from this type of antenna. A nanoVNA screen shot of sweeping the antenna from 7-30MHz is available at The SWR/Impedance values you report are typical of a 4
Here is my 2-cents opinion based on currently using both an OCF and two fan dipoles. 1. Kevin's available mounting situation may favor an OCF over a true dipole. It doesn't appear that he can effecti
40 OCFD: What most of the comments you've received probably (or should) mean is that you don't have a symmetrical/center-fed antenna, so you're more likely to have feed problems and common-mode probl
Joe, you are of course correct, but I think maybe he said 576 mohms, as in 576 milliohms, although he didn't type it very clearly. He couldn't ever have had a VSWR of 1.012 with j576 ohms. 73, Dave
Except that 50.1-j0.576 Ohms at 6.68 MHz and 33+j7.11 Ohms at 7.15 MHz do not make sense. Generally, the real part of impedance *rises* above "resonance" (along with the inductive reactance). On the
These can be easily dealt with, with a good balun and good common-mode choke. However, some people will aim for perfection and may ridicule nearly anything else... No, they can NOT be "cured" with a
For a number of years while I lived in a townhouse I used an inverted-V fan in the trees behind the house with 10M, 20M and 40M elements. The 40M elements had W9INN coils near the ends to permit 80-