[Elecraft] Evaluating Antennas...

[Ron D'Eau Claire]

Last night I happened to be reading the accounts of an early radio
engineer and came across what was perhaps the first example of the
dilemma every one of us face when trying to decide whether our antennas
are doing as well as they might. 

In November of 1902, Guglielmo Marconi had already proved that the
Atlantic could be spanned with transmission of the single letter "S".
Now he was desperately working on a system that would provide reliable
communications across that span from the station at Podhu in England to
Glace Bay in Canada. His chief engineer at Glace Bay, Vyvyan, kept
careful notes of the experiments. Here are a few of his comments:

"The first transmitting experiment was started..using a cone aerial of
200 wires. but no signals were received at Podhu. Various changes were
made, day by day, and transmission effected every night without success
until the 20th, when Podhu  reported signals received for the first time
although they were not readable. The aerial was then changed. and a
further series of experiments carried out with practically no results
from Podhu. On 5th December.for the first time some readable signals got
through. This was by far the best results obtained yet. The next night
during the same hours the programme was repeated with exactly the same
arrangements but nothing was received, and again on the following night.
It became evident that the great variation in reception must be due to
extraneous causes, probably variations in the conductive quality of the
medium. It was very difficult to determine whether one transmitting
arrangement (of the aerial) was better than another under these
constantly varying conditions."

("Marconi" by Giancarlo Masini, ISBN 1-56886-057-9)

So things have not changed one whit in 100 years. As we throw up our sky
wires and experiment with new "arrangements" we still find that the
"variations in the .medium" obscure our attempts to know for certain
which aerial works best. 

And every one of you who tinker and try and test are in excellent
historical company.

73

Ron AC7AC
K2 # 1289