Re: [amsat-bb] Gene's spreadsheet and K-band

[Mike73@xxxxxxx]

In a message dated 5/8/2003 8:55:27 AM Eastern Daylight Time, nx7u@cox.net 
writes:

> I noticed in going thru Gene's link budget 
> spreadsheet that when you enter circular polarization for the K-band 
downlink 
> you get an advantage...I thought the K-band downlink was linear polarized?  

K Band horn on AO-40 is linear, 23 dBi

> Shouldn't you actually take a 3dB hit using circular on K downlink?

Yup.

> (and of  course a potentially infinite hit using linear--but we'll think 
positive for 
> now).

If your downlink antenna is linear, you will see fades due to polarity miss 
match due to the bird being spin stabilized. How severe? On my 0.5 meter 
linear dish, it's essentially 100% loss. However, it doesn't last very long.