[amsat-bb] Re: AO-7 Mode C? (Or other reason for varying signal strength?)

[Andrew Glasbrenner]

As far as I know the 24 hour timer can only toggle between A and B, not 
C. Either way, the power output is likely to be more dependent on the 
particular illumination angle and total power generated by the panels 
rather than rather it's in B or C. Take antenna polarization and squint 
into account too.

Then again, you may be perfectly correct :-)

73, Drew KO4MA

Bill Dzurilla wrote:
> So, folks, does anyone have any thoughts or comments about this issue?
> 73, Bill NZ5N
>
> --- On Sun, 4/4/10, Bill Dzurilla <billdz.geo at yahoo.com> wrote:
>
> From: Bill Dzurilla <billdz.geo at yahoo.com>
> Subject: AO-7 Mode C?  (Or other reason for varying signal strength?)
> To: amsat-bb at amsat.org
> Date: Sunday, April 4, 2010, 10:52 PM
>
> Hi folks,
>
> Since starting my effort to work Europe on AO-7, I've found that the very low elevation sigs vary significantly on different 
> passes.  Some mornings I can easily hear my downlink and start working 
> Europe at 0.7 degrees elevation, while other days I can't hear myself 
> until 5 degrees elevation, after the window to Europe has closed.  Not 
> sure if this is due to band conditions, satellite polarization, 
> obstructions at certain positions, operator error, local noise, or what.
>
> Today I spoke with another experienced AO-7 op and he had an interesting theory: on the bad days (when I don't hear my downlink until 5 degress), the sat is in Mode C (lower power).  This seems to make sense, because there does not seem to be any middle ground -- I start hearing my downlink at either 0.7 degrees or 5 degrees, never at 2-4 degrees.
>
> Anyone have any thoughts on this?  Are we able to predict when the sat will be in one mode or another?  Or any other explanation for the signal strength variations?
>
> 73, Bill NZ5N 
>
>
>
>       
>
>
>       
> _______________________________________________
> Sent via AMSAT-BB at amsat.org. Opinions expressed are those of the author.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>
>