I wonder how many people make the mistake of thinking AO-7 is not transmitting (when it is) but the receiving equipment isn't adequate.

An illustration ... on orbit 51203 at 09:32 this morning, 30-11-07 at the start of the orbit I heard nothing at all ... absolutely nothing! from AO-7.

However, switching the polarisation of my aerials to vertical (from horizontal) resulted in a received signal of S3 ... and as the orbit progressed, the signal strength incread and the polarisation changed another two times on that particular orbit.

Remember !!! ... the propagation to all intents and purposes is different at various QTH's ... so the result at one QTH - (for instance, signal report) - is highly likely to be quite different at another QTH.

I would advise using your EARS !!! as a reference because meters are a complete waste of time in this particular situation/application.

I would thoroughly recommend switchable polarisation for LEO's. It doesn't have to be commercial and expensive. Mine doesn't even use coaxial relays - and it's built into an aluminium lunchbox ... don't laugh!, they're cheap and RF tight.

There's a full explanation on OBSERVATIONS ... (http://www.observations.biz) of why I don't bother with circular polarisation on LEO satellites.

73 John. la2qaa@amsat.org