Hi Barry, Much of this is at: http://www.w8ji.com/radiation&fields.htm and at http://www.w8ji.com/radiation_resistance.htm With any monopole antenna radiation resistance carrying uniform current radi
To do that we would have to have a coil that is either very large in terms of wavelength, has considerable distributed capacitance to "ground", or that violates basic laws of physics and electronic
about PVC Hi Larry and all, No matter hat the shape of the coil or what the mutual coupling from end-to-end, the only way current can taper is if current has a second path to ground other than the o
No one could accurately predict this Les, becuase there are far too many unknowns. Ground losses most likely dominante the system, since it sounds like you are forced to use a small ground system. T
Greg, That is a common perception but unfortunately it is not correct. We can NOT multiply voltage times current to obtain true or effective power in a system with reactance, unless we also know the
Hi Les, There is something on my web site about a Slinky Beverage. I even almost forgot it was buried in there! http://www.w8ji.com/slinky_and_loaded_beverages.htm There is a model you can download.
I've been copying a very wide and moderately strong spurious signal from the northwest (I'm near Macon) on 160 every morning. I can't quite identify the call sign but I'm very sure the station is fro
Woops. I forgot the 160 frequency. The frequency on 160m is 1852kHz approx. with light splatter from 1820-1880kHz. The AM frequency and station I **think** I have a match on is WTJS in Jackson, Tn on
By catching a clear callsign and city name, I've positively identified the strong BC station buzzy broken carrier on 1853 that is splattering and spitting from 1810 to 1880. (The broken-up carrier on
The cause really didn't matter to me, but the end-effects and who was causing it sure did! That thing was wiping out JA's and other weaker signals to the NW of me even down on 1820kHz. The carrier o
As general information, I just learned the spurious signal was caused by an unknown problem in one of several power output modules in a brand new transmitter. The only indication there was a problem,
W4RNL also points out how much poorer our soils generally are than we think they are. We also have to be careful because a lot of his data is unverified except through models which are also not verif
Hi Rick, My point was we should be more careful in saying something is "accurate", or that some entirely unrelated trend "verifies" a entirely different measurement parameter. It certainly is not tha
The important thing is we understand the limitations, especially that everything has some tolerance, and close calls (within a few dB) won't always rank things correctly. If we all lived by propagat
Since people seem to ask about amplifiers, I have added a new page to my web site with some preamplifier measurements. http://www.w8ji.com/pre-amplifers.htm Also a link to actual measurements of the
That is an overstatement of what actually occurs. Even a deep ground (say a foot or two deep) helps, it's just that closer to the surface is better. The skin depth on 160 is several feet to perhaps
You are trying for an absolutely unobtainable system noise figure if the receiver has any sensitivity to speak of. For example, a 250Hz selectivity receiver at -150dBm sensitivity would require a 0d
readings on useable If you have a problem with RFI, it is antenna size (system) related....it is not related at all to the dial setting of the analyzer. The problem centers around the fact virtually
The same voltage rating rule applies in a gamma match capacitor. http://www.w8ji.com/omega_and_gama_matching.htm Just read the gamma capacitor part. It works the same.