Topband: Run antenna

Tom Rauch w8ji at
Fri Mar 2 13:35:28 EST 2007

Here's how it works:

1.) If multiple antennas with response in different 
directions are directly mixed (at audio or at radio 
frequencies) S/N ratio is always lost and some directions 
will have phase nulling. It is always better to use ONE 
antenna with a broader pattern if you don't every want to 
miss someone from a null or lose contacts from signals 
falling into the noise.

2.) If two antennas are put into both ears in stereo, it 
still deteriorates S/N ratio. There isn't any destructive 
phasing, just a S/N decrease. If the operator has the 
training or ability to focus his hearing only on one ear 
(one antenna) the S/N decrease will be less. If the operator 
can't focus well on each ear independently, it will be more 
weak signals lost. The amount is full of variables but there 
will always be some stations missed. It will always be fewer 
than if the two antennas are simply combined either at audio 
(into mono) or at the receiver input.

3.) If you listen in one direction with good antennas, you 
will always miss quite a few callers from other directions 
in a contest. This is always true. Whether the number you 
pick up in the favored direction offsets the number missed 
just depends on the rates in the different directions and if 
the stations you miss keep trying at other times.

The difference on many of my antennas between listening in a 
favored direction vs. hearing something somewhere else is 
huge, sometimes 40dB. That means an S9 plus signal can get 
missed if the operator depends on hearing something "leak 

I think the best combination would be a low directivity 
antenna in one ear and a directional antenna pointed in the 
primary direction of activity in another ear.

73, Tom

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