Build Your Own Working Bino-Scope Unit


Something wehave always wondered regarding UFO sightings. Say its night, and you see a light in the distant sky. Is it really an airplane? Or suppose it's behaving oddly, performing maneuvers impossible for an aircraft, etc. Could the optical emissions coming from that object be identical to an ordinary 120V AC lightbulb? Specifically, is the LIGHT AMPLITUDE of that object pure and smooth DC? Or is it some kind of AC white noise or signal?

After all, nearly all manmade light sources are modulated as a result of their AC power supplies, so their brightness is vibrating with 120Hz audio frequency. Connect a solar cell to an audio amplifier, hold it under an incandescent bulb, and you'll hear MMMMMMMMMM at 120Hz (two flashes per 60Hz cycle.) Therefor we should ask: what sort of vibration might be imposed on those distant and mysterious lights in the sky?


UFO BINO-SCOPE SHOPPING LIST 1-A good pair of Binoculars. 2-A Small Solar Cell. 3-An Audio Amplifier. 4-A pair of Headphones. UFO BINO-SCOPE SHOPPING LIST 1-A good pair of Binoculars. 2-A Small Solar Cell. 3-An Audio Amplifier. 4-A pair of Headphones.

We taped a selenium solar cell to the eyepiece of a small 50X telescope, routed it to an audio amplifier, then pointed it at distant light sources at night while listening to the signal.

Incandescent streetlights give a deep hum, their AC light output is a pure 120hz sine wave.
Mercury and sodium vapor bulbs are nonlinear, they give a complex 120hz waveform.
Neon signs sound different, with a squealy high frequency buzz component to their 120hz fundamental.
Automobile headlights are DC, so we never tried viewing them.

Headlights are modulated by car vibrations, so we checked it out and yes, car headlights give off a continuous soft gonging sound even on smooth highways. Their filaments vibrate, and different types of headlights give different pitches of "bell" sounds.

Aircraft strobes are easy to detect as a loud clicking. Other aircraft lights *may* have a standard 800Hz modulation (from their 400Hz supplies), but we found that it wasn't loud enough to hear from distant aircraft lights. Perhaps the thermal inertia of their filaments tends to filter out all the high frequencies, whereas 60Hz is slow enough to be "broadcast" by light bulb filaments. Maybe with a low-noise detector and some bandpass filtering, the 800Hz of aircraft lights could be sensed.

Rather than using a telescope and a solar cell, we put together a better viewer recently. Binoculars can provide a parallel "sighting scope," even when one eyepiece is occupied by a photocell. A Seimens BPW33 P.I.N. photodiode and a low-noise opamp front end gives a bit more gain than a selenium cell. Headphones give much better low frequency response than a speaker. And the whole thing can be battery-powered and duct-taped onto a set of large-aperature nighttime binoculars. Any light source seen by your eye through one side of the binocs will be heard as optically demodulated audio picked up by the other side!

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