Static and crackling

Hi Luthier,
can you give a sound sample to us? Continuously increasing or decreasing pitch, not too fast? Crackling should not be typical for interferences from a nearby AM station or airport. Do you get distorted undefined signals in a AM receiver (long wave, middle wave)? That could be from home installations and electronic devices. 

What theremin is it? Thanks for a sound file if that's possible.

It was typical noise that sounded like grounding issues. It increased with the height off of the volume antenna.
It was not distortion of signal, but the crackles and noise typical of a short or bad ground. I returned it, and was told it was working perfectly when the builder received it back from me. The weird thing is it worked the first day just fine! Then on day two... static. Three amps,in two buildings, two different cables, no appliances or dimmers on, where I run all kinds of electrified musical instruments with no issues, even a cheaper beginner/toy theremin worked fine here.

The builder suggested radio interference and retuning it to a different frequency, but it made no sense as it had been working fine the first day. I believe there may have been an intermittent short of a component, or a micro-crack on a circuit board or something that may have been nudged back into place during my shipping it back. Rather than risk the builder’s retuning of the frequency not solving the problem I got a refund because I was told if it did not solve it, I would be responsible for the return shipping yet again. At $29 a pop, the shipping was not cheap.

So, I no longer have the instrument I wanted, have no theremin, and am very sad about it.

No hard feelings, though! The builder is a great guy, the theremin was lovely, and I’m sure this was a fluke, and just bad luck.