Topband: Small Loop does not receive weak signal on 160m BOUVET RX SPOILER

[Wes]

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