[Antennas] How can I tell if my signal is getting out?

2002年4月11日 11:39:39 -0500

While all this reciprocity discussion is still interesting - although it
has been beaten to death for some months now - I really think that no one
has answered his question yet: "why am I not making contacts?"
There are three aspects to making a QSO:
1. radiating a workable signal on a desired frequency
2. someone hearing that signal and responding with a call on an appropriate
frequency and time
3. hearing the response on the proper frequency and reacting to it in the
proper manner at the proper time
All this supposes that there are no confusions about who is on what
frequency and the time sequence in which things are happening.
I suspect thatJoe's problem is not so much in the signal level area or in
the absence of stations calling, but rather I wonder if he is (a) calling
on the proper frequency either to CQ or to answer a call and/or (b) is
tuning his receiver to the proper frequency with regard to his actual
transmitting frequency and the frequency a responding station is using. CW
frequency offsets being the seemingly complex topic that they are, there is
every prospect that a frequency mixup could be the source of the problem.
Not to put down the talent or ability of our questioner, but unless he
either has the experience or has had someone to instruct him in actually
using the radio to make contacts, I really do suspect "cockpit problems"
here as the reason for no contacts.
It is all too easy to call CQ on one frequency and actually be listening
for replies on another, and vice versa. Not understanding or using the
offset capabilities of the radio, or unintentionally using RIT or XIT can
result in sending in one place and listening in another with the result
being "no QSOs."
If at all possible, I would recommend that Joe find an experienced local
ham and get some hands-on cockpit drill. Even a reliable old war-horse like
the FT-101 - which is and was a great radio - can play tricks especially if
the CW offset (BFO injection frequency) is improperly adjusted, etc.
Joe, if you read this, find a local guy to work with you and then let us
know how you do. You should be able to work at least a few stations every
time you get on the air, even with your patio antenna.
Just a parting shot at the "reciprocity" business: don't forget that the
general concept was borrowed from circuit theory and extended to
electromagnetic propagation. In doing so, a lot of simplifying assumptions
and necessary conditions were introduced. One thing that is usually omitted
in the real world application is the effect of local noise at one terminal
of the circuit. The antennas, path, power levels, etc. can all meet the
requirements, but if Station A has a vacuum cleaner running next door with
an S9+20 dB local noise level and Station B does not, then all bets are
off. 
There are other flies in the honey, such as stochastic variation in path
properties, multi-path propagation, variations in antenna pattern effects
relative to time of day and ionospheric layer activity, and on and on.
It is unfortunate that reality intrudes so impolitely upon our beautiful
theoretical constructs! <:}
73/72/oo, George W5YR - the Yellow Rose of Texas 
Fairview, TX 30 mi NE of Dallas in Collin county EM13qe 
Amateur Radio W5YR, in the 56th year and it just keeps getting better!
QRP-L 1373 NETXQRP 6 SOC 262 COG 8 FPQRP 404 TEN-X 11771 I-LINK 11735
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Pat W wrote:
>> This principle of reciprocity is something new for me too. IT makes a lot of sense however. In essence, the received signal strength is dependant on BOTH antennas, not just the poorest one. Increasing the efficiency of either antenna will increase the received signal strength. This web site from G4FGQ is where I got the information. I highly suggest this to all. http://www.btinternet.com/~g4fgq.regp/