### Just report

I tried to excite the drumhead mode of ETMX and to receive the beacon from the mode with Moku:Lab remotely during FPMI lock.

When I sent an excitation signal whose amplitude is 2 Vpp and whose frequency is 23.6911 kHz to ETMX from nearby the OMC rack, I found the peak in the demodulated signal of AS RFPD (Fig. 1).

The red line in the figure is the signal demodulated by I-phase, and the blue line is the one demodulated by Q-phase.

When I turned off the excitation, the peak disappeared. I swept the excitation frequency from 23.6911 kHz to 23.6915 kHz, I found the peak got maximum at 23.6913 kHz. (Fig.3)

I think this peak is the beacon signal by ETMX drumhead mode probably, but I will examine it in detail later.