Thanks for this George.
When I posted earlier I said: "Looking at my chances of working 3Y the optimum
time is their sunrise (~3:30Z) when I am in complete darkness and straight
across the terminator. They will have the sunlit ocean to their rear and the S.
American landmass toward me. Maybe someone can enlighten me, but I fail to see
how a directional antenna will improve the SNR of my signal at their end. "
What George says is the point I was less eloquently trying to make. Of course
this doesn't account for local conditions, rain and snow static, etc.
Wes N7WS
On 12/25/2022 8:36 AM, GEORGE WALLNER wrote:
In my experience, a DXpedition does not need an RX antenna on 160 for the
first two to three days. During that time they are working the big guns with
strong signals. The RX antenna is needed to give the weaker stations a chance
once the big guns are out of the way.
In case of Bouvet, most of the signals will be coming from the NE or NW
direction. Their "back" will be towards Antarctica, which is not a major
source of noise. The F/B of an RX antenna will contribute little (but not zero).
The bigger problem will be that Bouvet Island is in the southern hemisphere,
where it is summer this time of the year. Late-afternoon or evening
thunderstorms taking place south of the Equator will generate a lot of noise
(think of Africa, Amazon). Most of that noise will be coming from the same
direction as the the NA and EU signals, in which case an RX antenna may not
help (much). Their biggest challenge will be working the Far East (JA
especially). That is where a good RX antenna, pointed in the right direction,
could help because most of the noise would be coming from its side. With
marginal TB QSO-s even a fraction of a dB in S/N can make the difference .
Also, they wont have much darkness to work with. It will be tough. I would
make the loop bigger to improve the S/N ratio and improve the JA-s' chances.
73,
George,
AA7JV/C6AGU
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