Hi, Alberto Why do I smell a strong scent of EH-antenna ??? Poor Maxwell is turning in his grave... It seems funy EH-"antenna" realy works. But surface curent of a coax realy radiate, not "antenna" i
Hi, Jim and Group If we describe this inductance as inductance of shorted piece of guid line we can easy get a formula: L/l = (Zw/Zo)*mu0 where Zw is impedance of line, Zo is impedance of space (377
For those that do not know. Research around Europe has shown that VERTICALS are the only antennas suitable for Transmitting on LF. Loops are fine for Receiving, little or large but the bigger the bet
However anomolous results can also be of interest. For example, it is not uncommon for researchers to sweep minor, irritating, results under the table. Any anomalous results are of grate interest! Bu
Dear J, Elnec shows the radiation resistance of the antenna with all resistances set to zero, to be about 0.02053 Ohms. It seems to be very strange. Simple formula for top loaded vertical R=1600(H/la
Elnec was correct, but I made a typographical error. The decimal was one place off. It is 0.2053 Ohms, not 0.02053 Ohms, and is close to the 0.16 figure you had for an antenna height of 20 meters. O!
7.6 Ohm of coil resistence is reasonable. But it can be decreased if increase a diameter of a coil. Very aproximative coil Q-factor is about coil diameter in milimeters if step of wireing is optimal
7.6 Ohm of coil resistence is reasonable. But it can be decreased if increase a diameter of a coil. Very aproximative coil Q-factor is about coil diameter in milimeters if step of wireing is optimal
Alexander, how much topload on your vertical? Mine is 22m high with 300pF top. R at feedpoint is 24 Ohm. After some tests (compared with DCF39) and calculations the radiating restistance seems to be
The antenna is in a flat mountain valley far from any trees, but it has a long low house running from about 7 meters to about 27 meters from the base of the vertical tower. Other buildings and wiring
Certanly may be it is more easy to build more powerful TX not such a complex antenna because You have ERP restriction. All of this can be more interesting fo Russians where there is no ERP restrictio
Dear Alberto, I think this is a joke only: The new Super Power Positive Feedback Antenna (SPFA) is an advanced developed antenna to CFA antenna , it is the antenna for the century. ..................
Dear J, Alex, Thank you for your continuing help. I am retired and live on a fixed, small income. Litz (sp?) wire in not being considered. Solid coper wire yelds Q-factor about 1/2 of Q-factor with L
Dear J, Since optimum Q in an inductor with solid wire requires an air space between adjacent conductors equal to conductor diameter, would it make sense to wind a coil with two varnished conductors
Though it is a good idea. May be I understand Your idea not right. Two (or more) wires connected in paralel on the ends can be used if wire is too thin to acive coil length of 1/2 of a coil diameter
On Thu, 13 Jan 2005, Alexander S. Yurkov wrote: years ago. Unfortunely I have forgot where is my writings with this formulas. Somewere they are but it is dificult to find them in my 'pile up' of diff
Dear J, I was thinking of reducing the solenoid loss by paralleling two or more #17 wires and close-winding them. If I parallel wind three #17 wires will it be worth the effort in reducing coil loss
...About 1.2mm, according to my ARRL handbook. Acording to estimation done number of turns to get about 700 Ohms is 55 if former diameter is 320 mm. Optimal length of solinoid is about 160 mm. If wir
I will monitor freq from 137690 to 137750 next night (18-00 to 02-00 Z 24 Jan). Frequency resolution will be 0.13 Hz (best resolution permited by my old computer). This means abt 8 sec FFT. Also aver
