13 replies to this topic

[Bodhiboy]

Has anyone else ever used a Theremin at an investigation? When I was at Fort mifflin, one of our group members was playing on a theremin for several hours. Another group member who was a sensitive said that this was really agitating the spirits. We had ALOT of activity that night from screams to bottles mysteriously breaking. So has anyone else ever experimented with this? It would be interesting to set it up in a room and see if it starts going off by itself.

[Joven76]

This is a very interesting idea... I too would be very interested to see if this, set up, would go off on it's own...

[OMPRDave]

Will have to research this...never even heard of one before. Looks like a basic amplifier head with two varieties of antennae...have to get back to this thread later.

[OMPRDave]

I would have to discount using this because it's introducing sound to the environment and rendering any EVP useless. Has anyone done a written study to explain what they believe is happening to link the use of a Theramin to studying paranormal phenomena? I would guess that a boom box with some weird music would have about the same affect. A hypothesis to suggest why this can induce paranormal experiences would be helpful.

Sorry about the double post...the edit feature locked up again.

[CaveRat2]

An interesting concept, I may have to test it. Certainly it will render any EVP useless while it is being utilized, but that doesn't mean that it should be totally disregarded. It may well prove useful in conjunction with photography for example where sound is not a direct factor.

Since the theremin works on the capacitance loading effect I would also wonder about its use as a detection device. Variations in loading cause a change in frequency, so might this be a means of detection? I would say it is an area for study, it could prove ineffective but until the experiments are done we won't know for sure.

[Joven76]

CaveRat, on Sep 15 2009, 10:32 AM, said:

Since the theremin works on the capacitance loading effect I would also wonder about its use as a detection device. Variations in loading cause a change in frequency, so might this be a means of detection? I would say it is an area for study, it could prove ineffective but until the experiments are done we won't know for sure.

Exactly what I was thinking... After reasearching Theremin's online, I found out they're rather expensive... Time to start saving...

Edited by Joven76, 15 September 2009 - 09:46 AM.

[CaveRat2]

For the technical among us, there are several sites with plans to construct your own therimin. Most don't require a particulary expensive array of components, Most of the components needed are easily salvaged from other electronics devices which technicians usually have laying around in heaps. The few specialized parts are not that expensive, I would say most could put one together for under $40 using stuff you likely already have laying around..

[Joven76]

Well, if you could build me one for that price, I'd gladly pay it... I am technical, but I not as much as you Caverat!!!

[Bodhiboy]

It really did seem to have an effect in that we got pehonomena at the fort, such as hearing "the screaming lady", that hasn't been heard of for two years. The psychic said that it had an agitating effect on the spirits. Later that night a beer bottle exploded with such force that it left powderized glass as if it had been crushed by a rock. I saw this happen 2 feet away from where I was trying to sleep.

[OMPRDave]

found this by accident today

Edited by OMPRDave, 26 September 2009 - 08:06 PM.

[Kelli Chases Ghosts]

Interesting idea but inherently flawed. The Theremin uses two oscillators at a high frequency well above the audio range, the outputs of which are added together to produce a heterodyne, which is then detected and amplified so you can hear it. The tone you hear is the heterodyne, or the difference in frequencies between the two oscillators. For example, if one oscillator is running at 150 kHz and the other at 155 kHz, you will hear a 5 kHz tone. The problem with this is that such free running oscillators are inherently unstable. Any temperature change, fluctuation in power supply voltage, even nearby RF sources will interact with a circuit like this and make it unstable.

There are things that could be done to make it as stable as possible such as making one oscillator crystal oven controlled in the HF range and dividing it down, which would greatly increase stability of that oscillator, possibly down to a few Hertz. However you still have instability in the other oscillator, which *must* be controlled by an R/C or L/C circuit and not crystal controlled. You could add regulation to the power supply, but even a few hundredths of a volt could change the oscillator frequency. It would have to be a VERY stable supply regulator, a 7800 series regulator probably isn't going to do the job.

This is why any device that is worth even experimenting with is very expensive. Even with stable oscillators you still have the problem of eliminating other factors that will affect the frequency of the free-running oscillator. Just turning a light on in another room or people moving around even several feet away could affect it. Strong RF fields will affect it. You have to take all this into account when experimenting with stuff like this. It's like the K2 meter that 99 times out of 100 is used improperly.

~K

[CaveRat2]

Kelli, I agree with what you say, but I see this as a positive rather than a negative. If one oscillator is crystal controlled and held to extreme tolerences, and the other used as a sensing detector, anything that even slightly loads the LC circuit is going to result in a shift of frequency. Since we are using HF frequencies of a 100 kHz or greater , even a .01% shift will result in a shift of 100 Hz in frequency. This will result in increased sensitivity over the use of lower frequencies, since a .01% shift at 1 kHz would only result in a chnge of 1 Hz. This would be difficult to detect compared with the 100 Hz shift.

I agree regarding the use of regulation and stability, the support electronics will need to be extremely well regulated. Possibly the use of DSP would allow for this level of stability in the generation of the reference signal. And certainly EMF and ESF monitoring of the area in question would need to be conducted to detect any sources of false positives. Expensive? Yes, but it is do-able as an experiment.

In this manner the Therimin concept may be considered as a means of testing to determine if such methods may be used to detect paranormal activity. I want to emphasize this use is only as a theory; I am NOT impying that a Therimin will detect spirits, only that the concept be explored and tests run to make that determination.

[Kelli Chases Ghosts]

CaveRat, on Sep 29 2009, 11:35 AM, said:

Kelli, I agree with what you say, but I see this as a positive rather than a negative. If one oscillator is crystal controlled and held to extreme tolerences, and the other used as a sensing detector, anything that even slightly loads the LC circuit is going to result in a shift of frequency. Since we are using HF frequencies of a 100 kHz or greater , even a .01% shift will result in a shift of 100 Hz in frequency. This will result in increased sensitivity over the use of lower frequencies, since a .01% shift at 1 kHz would only result in a chnge of 1 Hz. This would be difficult to detect compared with the 100 Hz shift.

I agree regarding the use of regulation and stability, the support electronics will need to be extremely well regulated. Possibly the use of DSP would allow for this level of stability in the generation of the reference signal. And certainly EMF and ESF monitoring of the area in question would need to be conducted to detect any sources of false positives. Expensive? Yes, but it is do-able as an experiment.

In this manner the Therimin concept may be considered as a means of testing to determine if such methods may be used to detect paranormal activity. I want to emphasize this use is only as a theory; I am NOT impying that a Therimin will detect spirits, only that the concept be explored and tests run to make that determination.

We're very much on the same page, CaveRat. After reading many of your posts I have no doubt you would make it a controlled experiment. My post was mainly geared towards those who are likely to go out and buy a cheap version and proceed to proclaim that every squeal from the box is a ghost -- and you know that some reading this are going to do just that!

This actually goes hand in hand with my own research, which is based on a conclusion I came to a long time ago based on experimentation and observation -- more on that later....

[Kelli Chases Ghosts]

Oh, BTW... I would be more apt to take the output of one of these and graph it than to simply listen to it. I think the result would be much more revealing.