Another option to increase the efficiency is to raise the point of maximum current well above ground, by using a K2LQ double L. http://www.yccc.org/Articles/double_l.htm Whichever is easiest (inverte
I guess the spark plugs might help protect your 1Mohm resistors from lightning, so they can take care of bleeding off the static that would otherwise build up gradually? :) -- All rights reversed. __
You can calculate this the other way around. First, build an antenna (say 1/4 wave vertical) with an exceedingly good ground system (say 120 1/2 wave radials). Assume that system has near zero ground
You may not strictly need radials, but the point of maximum current is still only 1/4 wavelength above ground. This means that: 1) the ground loss due to not having radials is not as ridiculously hig
While I agree that most hams are cheap, I do not believe it makes any economic sense when it comes to connectors. Risking the finals of your $400 radio, in order to save $1.30 per connector (for at t
Someone who sets up a vertical antenna temporarily and only has time, space or material for a couple of radials may be better off by raising the feedpoint way off the ground. This can be done either
I am looking at building a few shortened-with-capacity-hat vertical dipole arrays for the coming winter, and am wondering what kind of relays to use for antenna switching. I am looking at DPDT relays
Thank you Felipe, It looks like the G2RL-24 relays are the DPDT relays that I want. They are available in various coil voltage ratings, but it's easy to find the 12V DC ones. Looks like Mouser has th
I am planning a few vertical arrays (vertical dipoles hanging from trees) for this fall, and am wondering what kind of surge protection people use on the relay control cables. I am looking for someth
I'm hoping that the invisible fence wire is built to last, because it's cheap and easily available :) -- All rights reversed. _______________________________________________ _________________________
Some people apparently have noticed a lot of difference. However, in this thread the person who noticed the most difference, also had the tallest & widest trees... I imagine a wider tree not only cap
I think I get it now... 1) If the element is very low resistance, the RF will induce a lot of current, but it will get re-radiated. 2) If the element is medium low resistance, the RF will induce a fa
Indeed. The way to protect your house, is to ensure that everything in your house is at the same potential. Normally this is easy, since stuff only comes into the house in one spot, and every ground
Apparently the government, at least MITRE, has been building frequency-independent directional phased arrays for quite a while now, with voltage probe antennas, an amp at each antenna and coax delay
Thank you for that schematic. How can you aim your array east or west, when the west element has reversed polarity on its transformer? Am I missing something? -- All rights reversed. ________________
Alternatively, if you do not have space for radials, you can reduce your ground losses by elevating the center of current above ground. You can do this by building a double L antenna: http://www.yccc
If so, is there anything special about feeding the array? The feed point impedance for inverted Ls with FCPs (and double Ls, for that matter) will be different than for ground mounted verticals with
On 08/13/2013 10:31 AM, Dan Schaaf wrote: The HiZ clearly outperforms the K9AY loop and coax mag loop. Probably will also outperform the SAL. The HiZ 4 square and 4-8 Pro is a phased array and so rem
There is another reason. Sound frequencies are really low, so speakers that are run out of phase (and in the same room) are close to zero wavelengths apart, and can actually cancel out the bulk of ea
Yes, the frequency at which the choke works best changes with inductance. G3TXQ has a nice page on that: http://www.karinya.net/g3txq/chokes/ I suppose the second one can take the strike if the first