Sun Partial Eclipse Feb/20th/2015

The following diagrams show the change in sun flux during the sun eclipse as seen from my place. The recording was suggested by Franck (F5SE) with the goal of comparing the drop in UHF sun flux with the theoretical sun flux in the optical portion of the spectrum:
Latitude 45 27 45 N Longitude 8 00 00 E
The sun flux was observed at 23cm (1296 Mhz), the effect of the moon was a drop in solar flux close to 5db (to less than 1 third compared with normal)

The first diagram include the samples taken from a fixed antenna position starting when off target (pointing to a cold sky spot) end ending when sun was no more visble by the antenna while the second is the whole duration of the eclipse but when already pointing at the sun.

From cold sky

Pointing to sun

F5SE data analisys

The collected data where then sent to F5SE to do the analysis and the followig graph was produced as result by Franck.

From the graph is easily visible how the variation in the optical is much deeper than what observed in the UHF spectrum.
The explanation is the Sun's corona which is not visible but extends millions of kilometres into space around the sun and radiating at radio frequencies so making the sun much larger.