Fig3. RATAN-600 power aberration curves.

C-Zenith mode(H=90 deg.) with 400 meter aperture.
B-Zenith mode(H=89 deg.) with 400 meter aperture.
D-Radio-Schmidt mode with 100 meter aperture (H=45 deg).
E-Ordinary mode with 100 meter aperture (H=45 deg).
Red or blue curve  and 2 channels per feed may be used