[Lowfer] 160m vs 1600m

[Ed Phillips]

Bill Ashlock wrote:
> 
> Ed and all,
> 
> Let's list what is similar between 160m and 1600m and what is not similar.
> 
> Similar:
> 1. Same formula for resonant frequency
> 2. Same formula for radiation resistance
> 3. Same Maxwell equations for E and H field formation
> 4. Same surface wave 1/d signal falloff (Not accounting for Attenuation
> Factors)
> 
> Not similar:
> 1. Effect of the soil immediately surrounding the antenna
> 2. Surface wave Attenuation Factors are much less at 1600m. (This is the
> additional signal attenuation with distance that must be added to the 1/d
> signal falloff)
> 3. Space wave propagation is grossly different
> 4. Efficiency for a typical backyard-sized antenna is much less at 1600m
> 
> It looks like the similarities all have to do with the antenna itself while
> the dissimilarities relate to the environment in which the antenna is
> placed.
> 
> Bill A

	No arguement, although I thought this discussion was about the antenna
systems and not propagation effects.  I think 1. and 4. are the issues
that count.  Almost all of us have lousy grounds.  The radiation
resistance of an antenna depends on the height in wavelengths, so a 50
foot antenna at 180 kHz would have similar properties to a 5 foot
antenna in the 160 meter band, where lousy ground resistance would be
just as hurtful.  The only difference at 160 meters would be the fact
that a suitable counterpoise system would be much more convenient to
build and install.  Too bad we don't live on salt marshes which somehow
still permit us to have grass, etc.

Ed