Mak, When the power from the solar panels is less than optimum, the satellite's control system starts to send random code from the memory, which will turn the transponders on or off in a predetermined sequence assuming there is enough voltage to control the circuits properly ... BUT !!! ... several factors can and do change the system parameters.

This is what I've been babbling on about all along for several weeks now. At first, everybody assumed I'd gone round the bend ... (mad) ... with my 'Greyline' theory but now, a few people are actually considering the possibility. Unfortunately, I'm not very coherent so I leave the "explaining" to GM1SXX ... where he can do all the work and I can take all the credit ... a 50/50 division of labour.

We have to distinguish between actual fact, that which is wishful thinking and probability.

We can safely assume that the Old Girl's behaviour and mode selection/power output is (indirectly) determined by the solar array ... (read: amount of sunlight) ... and directly by the onboard electronics.

(That was mistake Nr: 1 ... calling a female !!! an "Old Girl").

Your solar panel and my blue weggie theory (*)... (thanks to GM1SXX for providing the "space" name for the Greyline) ... do seem to fit the facts ... even if we can't prove it.

http://www.observations.biz/Joint_Observations/Observations_14_10_2007.htm

The onboard electroncs *MAY* be explained after GM1SXX and I have got our thieving little fingers on the original schematics ... (which are still in Washington "as we speak")

(*)

Any self-respecting American knows what a "weggie" is but in this case it's Manchester vernacular for "wedge" and has nowt to do with "cheeks" of any kind.

73 John. la2qaa@amsat.org .....................................................................................

From SV1BSX.

Well John, definitely the "Old-girl" is back again very Loud the last 2 days. Last evening I was QRV on Mode/A, the signals was SUPER also on this Mode. Never I heard it too much strong.

So, I wondering why this "drop down" the last days.

Have you any idea about the spin of this Satellite? I was thinking that, the AO-7 is octagonal. So, the Solar panels are numbered No1, No2, No3.... No 8 (each one on each side of octagonal).

If we have ie the No2, No3 & No4 Panels with limited Power output and the Spin is Low, may be here we have the following scenario:

a) when these "limited power Panels"(No2,3,4) are forward to Sun, the Satellite is very weak due to poor Power budget. b) when the rest-good Panels are forward to Sun, the Satellite is stronger. ..................................................................................

That explain partially the mystery, why the Satellite is a bit stronger when the Satellite is approaching to the Daylight. Simply, the rest "good" Panels help a bit the (low) Power bugdet even if not straight-forward to the Sunlight.