Actual parallel line experience: One Field Day we arrived at our usual site to put up a 300 foot around horizontal loop. We usually corner fed the Delta shaped loop at a corner with 450 ohm line we k
As I said in my closing remark in an earlier post: "I realize that we'd like to eak out every dB we can, but in the end, it makes little to no difference on HF." If one can match the load, using what
Bob is right! In the end, propagation will dictate. External conditions have more of an effect than the subtle differences over which we have control. Sure we can increase efficiency, yet the results
We're talking here about reported changes in loss that - if true - would be equivalent to a 5dB change between dry and wet on a 100ft of ladderline feeding a doublet on 10m. Are you folks trying to t
Steve et al: I'm not saying that loss does or does not change with the vinyl type window line between wet and dry. I do agree with your results in that loss does increase with a wet line as opposed t
The other factor that I don't think has been mentioned is ground loss of the transmitted signal. For horizontal antennas, antenna height is the major factor, and for vertical antennas, radials. The i
Bob, Perhaps I had better explain clearly why I am carrying out these ladderline tests. I believe that the "wet" ladderline losses reported by Wes Stewart, and those predicted by at least two of the
I totally agree. Your measurements are "real world" and correct! I've used ladder line of various types for years and very successfully. Even at one time I used it, actually the open wire version, to
How big are the ground losses? Are they the difference between an EZNEC prediction over perfect ground and what it says over average ground assuming average is what you have? Is it the difference bet
It is not just the quality of the ground, but rather the proximity to the ground. Ground losses are present for a low horizontal antenna regardless of the quality of the ground. For a vertical antenn
That's what I've been doing, modeling antennas at different heights over different grounds. But the pattern changes too. Dipoles become more omni directional. That by itself will change the maximum g
Jon, The radiation pattern of a dipole at 1/4 wavelength above ground is circular shaped in both the vertical and horizontal planes. As the dipole is lowered in height, the pattern changes to focus o
Hmmm... I guess I am the odd man out... again. I thought all these little losses are cumulative and can add up. Sorta like getting consecutive sentences, instead of running concurrently -- it is not
This is the quote I've wondered about. It's from Bob Orr, W6SAI's, Antenna Handbook. "Antenna radiation resistance is influenced by antenna height. Assume the antenna is an 80-meter dipole. A common
Now re-run EZNEC with the dipole at 25ft and at 55ft over average ground, and compare the losses reported by EZNEC with your figures; you'll see something very different! Orr's "logic" is way too sim
Steve, Where are you getting losses out of EZNEC? I did re-run the the dipole at 25 and 55. As expected, all sorts of things are different. But where are you reading losses? Jon _____________________
Sri Bob, I disagree with you. It all depends on how you operate. If you hang out on the low bands and have local skeds, then you are right. But if your operations, like mine, are mostly within big co
Run any FF 3D plot and look at the Average Gain figure; it will tell you what fraction of the total input power is reaching the Far Field. If you set the wire losses to zero, you'll be left with just
I hope this does not add to the confusion too much. However... Radials really only apply to quarter-wave verticals. The reason is that the radials allow the field to act as though is is a half wave a