  The preflare phase of the flare SOL2011-08-09T03:52 is unique in its long
duration, its coverage by the Reuven Ramaty High Energy Solar Spectroscopic
Imager (RHESSI) and the Nobeyama Radioheliograph, and the presence of three
well-developed soft X-ray (SXR) peaks. No hard X-rays (HXR) are observed in the
preflare phase. Here we report that also no associated radio emission at 17 GHz
was found despite the higher sensitivity of the radio instrument. The ratio
between the SXR peaks and the upper limit of the radio peaks is larger by more
than one order of magnitude compared to regular flares. The result suggests
that the ratio between acceleration and heating in the preflare phase was
different than in regular flares. Acceleration to relativistic energies, if
any, occurred with lower efficiency.
