[Moon-net] one-way propagation

[David Anderson GM4JJJ]

The formula is:

The Best TX polarity for your station = the Polarity you are best  
receiving the other station on + (2 x Spacial offset between the  
stations)

So for any station, using any polarisation, the best time to avoid  
the dreaded one-way effect where one station cannot hear the other,  
but the other can hear the first, is to go at MNR=0. Spacial offset =  
0 or 90 degrees.

Conversely MNR is high when spacial is 45 or 135 degrees, meaning you  
have to transmit on the opposite polarity to that which you are  
receiving best.

Hope that helps!


On 4 Mar 2007, at 19:15, Heinz Bordé wrote:

> Hi all
> Last weekend several skeds failed because one-way propagation. W- 
> stn copied every sequence but European stn had nil. Most guys have  
> only H-polarised antennas and have to live with that.
> But I have x-pol and can react on that. But I´m not sure about how  
> to do.
> WSJT tells us the polarisation angel(VIEW-ASTRONOMICAL DATAS-DPOL).  
> As far as I know:  DPOL ~ 45° means = one-way propagation.
> If DPOL is so during a QSO between Stn A and Stn B, one stn will  
> get a H-signal and the other one will get a V signal. But who will  
> get what?
> And because DPOL can be - or + : what does it mean for me?
> Perhaps someone can tell me the law so I can react with my antennas  
> to the values, WSJT (an even other moon tracking programmes as  
> well) tells me.
>      73 Heinz, DM2BHG
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73
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David Anderson, GM4JJJ         E-mail: david at gm4jjj.co.uk
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