At 10:35 AM 2004-06-05, Dan Levin wrote: Here is what I know. 1) I will build a 74' vertical out of ~46' of Rohn pushup mast topped with ~28' of aluminum stinger. 2) Add three our four top hat wires
At 05:14 PM 2004-09-01, W5UN wrote: I have a question for any of you who have experience with adding radials and making measurements of the changing impedance on a 1/4 wl ground plane. Another view i
At 05:29 AM 2004-12-22, Peter PA3AUC wrote: Now take as an example an open-ended, 10m long piece of RG-58 with an assumed attenuation of ~2 dB/100m at f = 1.8 MHz, and a velocity factor of 0.66. Inse
At 11:26 AM 2005-01-13, Joe Wilkowski wrote: I have built a couple but have no way to verify the integrity of my work. I am phasing two Pennants and I swear I see no difference in gain or rejection v
At 12:52 PM 2005-02-08, Rick Darwicki N6PE wrote: A full size 1/4 wave 160 vertical shows a 1.41 db max 3D gain and an average gain of -3.63. Used Mininec/medium ground. All of the bent, twisted and
Not to defend the horizontal loop as a great antenna, but there isn't much of a tendency to null on the horizon compared to a dipole at the same height. Mounted at 1 wavelength high, the signal at a
I'll forwarded some of the EZNEC models I've used to Tod. The Flag is very easy to model, since no ground connection is involved. The Pennant version is a bit more difficult, since the feedpoint is b
Kevin, This antenna should perform well for DX on 160m. With 65 foot vertical and 95 feet horizontal wire, the feed impedance is about 30 ohms plus ground loss R in series with about 189 ohms of indu
When I was a young engineer, fresh out of college, designing and breadboarding wideband amplifiers, my experienced mentors always had me check for UHF or higher self-oscillation when there were stran
If the feed impedance of an antenna isn't 50 ohms and the feedline length isn't a multiple of 1/4 wavelength, the resonance (zero reactance) at the antenna and the resonance looking into the feedline
One alternative is to use a hairpin (beta) match. Add enough series inductance to the bottom of the vertical wire to give 21-j25 ohms (j71 - j25 = j46 ohms or 4 uH), then add a j42.5 ohm coil (3.7 uH
You can get a fairly good idea how this works using EZNEC. - [If you aren't an idiot and in a hurry and make several errors like N6RY did! I erroneously used a 20' radius hat, not a 20' diameter, plu
Tim, I ran these in EZNEC with #14 copper wire over Mininec ground with 17 ohms in the ground lead. Note that "Z" includes the 17 ohms. Lengths are resonant at 1.83 MHz. 1:1 SWR referenced to feedpoi
You didn't say what was supporting the vertical part of your Inverted L (tower? Yagi?), nor what type of wire you used, but it's likely that your antenna is resonant just under 2 MHz. With your modes
While I largely agree with Tom's point, its also true that before models were widely available, the amateur literature was full of broad and exaggerated claims about antenna performance, even if you
The carrier is just audible here at 8:50 am local time near San Diego, just above my abysmally high S7 noise floor (in the 250 Hz filter). It was much stronger on Saturday night during the Stew, maki
Ford, This may seem like an intuitive way to estimate TOI, but it most likely isn't related to the TOI at all. For example, an amplifier that will produce no more than 0 dBm output no matter how hard
It would probably be difficult to detect much difference in low angle signal between your current configuration and a shorter version. The signal for close-in stations via high angle paths could drop
I sent Neil a version of this with 5 pattern plots, so sorry if it is a little cryptic. I was surprised that the pattern for the beverage with the angled end section wasn't all that bad. If anyone is
For an inverted-L with approximately equal vertical and horizontal wires like yours, with a very good ground, the resistance should be lower than 36 ohms. My NEC-2 based model shows about 29 ohms of