Just finished an acoustic test of the EMDrive V3 and got interesting results:

Neither my milligram scale nor the interferometer with its relatively heavy table was able to detect any force due to noise.

I tried to pick up some force by attaching an electret capsule to the cavity, modulating the output power with a low frequency and looking into the acoustic spectrum (with HDSDR) - and voilà, there are some results.

Of course, this quick test doesn´t prove that the force is directional and not just a vibration.

But it shows that the peak only occurs around the resonant frequency of 24100 MHz for which the cavity was designed - and stops when no modulation is applied or the frequency is too much off the center frequency.

What I didn´t check yet is if the picked up signal is just the EMI of the transceiver. I´ll check it later of course - anyway to avoid trolls to call my science "bad" - more tests will follow

Additional information: The peak is not at the modulation frequency (76 Hz) but in the kHz range - it changes when I change the modulation frequency. Is it an alias effect or maybe a harmonic on the mechanical resonance frequency - I´ll have to take a closer look. The HDSDR software is usually used with an radio receiver so the frequency display under the waterfall was wrong (so I blacked it out). I´ll need to make the correct settings to see the correct audio frequency of a peak - I´ll do it in the next post.

Anyway this result is just preliminary, I posted quickly what I just did - I´ll check if it´s also happening when the electret capsule is not attached to the cavity but just nearby.