Crystal Radio Magic

[madhatter]

I wanted to post a comment.
I realize that we can twist and fiddle fart all we want with the mathematics to get results we want. the math in reality should be the theory and the experimental lab work is testing that theory, when it doesn't match or the results are different its back to the drawing board to re-do or re-calculate the math again.

Math is a VERY powerful tool in setting up a theory and testing it. If there is a pattern where experimental results fit the mathematics used then expanding on the mathematical theory gets a bit easier however one still has to be careful that we don't start to effect the results by manipulating the results thru the mathematics used.

Thankfully a lot of the base math is known and results are predictable, we are though when getting to the extra coil moving into the unknown. coil winding and manipulation of fields thru various winding designs is nothing new, this is not what Eric or Tesla was doing though. instead of trying to force or manipulate the fields Tesla was using the base parameters of the fields to manipulate them. Steinmetz covers this with the J operator in hyperbolic form, Clifford algebra is another useful tool though it's basis was quaternions - another story for another day

The goal is to get to L&C to match in harmony, nondestructive resonance. once achieved there should be a rotation of the B field to where the conjugate pair is no more, this will give rise to velocity of the wave faster than C. simple in theory but highly complicated in practice due to the sheer number of parameters involved and that the mathematics for engineering this are not finished.

Now here's the 64 trillion dollar question (inflation ), when the B field is longitudinal to the E field, is the extra coil still inductively coupled to the secondary? or is it now in electrostatic phase coupling? it needs both to achieve resonance, but once there what happens? is it the elusive sink and radiator Steinmetz theorized?

[madhatter]

@ jake

Is this what your circuit looks like?

you don't need a full bridge rectifier or capacitor for the LED, or at least I don't. single diode and led with leads shunting top and ground will light the LED nicely.

[xee2]

@ madhatter

Thanks for the info. How far are you away from the transmitter? I would try this but the nearest transmitter to me is about 50 miles away.

I know nothing about this antenna design, but as an ex-ham the top coil looks like an inductive matching coil that is used on ham whip antennas that are shorter than 1/4 wavelength. When the whip is less than 1/4 wavelength it looks like a large capacitive reactance. Putting an inductor in series with the capacitance cancels out the reactive components and makes the whip look like a small real impedance instead of a large reactive impedance. This makes it easier to get power into and out of the whip.

[madhatter]

@ madhatter

Thanks for the info. How far are you away from the transmitter? I would try this but the nearest transmitter to me is about 50 miles away.

I know nothing about this antenna design, but as an ex-ham the top coil looks like an inductive matching coil that is used on ham whip antennas that are shorter than 1/4 wavelength. When the whip is less than 1/4 wavelength it looks like a large capacitive reactance. Putting an inductor in series with the capacitance cancels out the reactive components and makes the whip look like a small real impedance instead of a large reactive impedance. This makes it easier to get power into and out of the whip.

Ahh, well the radio setup was too problomatic and that transmitter is roughly 36miles away.

I turned my attention to smaller scale and built two sets CW and CCW coil sets at 4Mhz.

This is a bit different from std radio reception, the secondary is in radian length. but the extra is very different. It's basic design is based on the propagation velocity increased by 157.08% over C. which increases the length to fit the increased wave length.

the secondary is 1.570 radians in length or 90*, the extra is also the same 90* but at the increased velocity of C by 157%. the spacing and wire ga are designed to create a self resonance within a 1:1 H/D ratio. As you can imagine nearbody capacitance becomes an issue as it's highly sensitive. The extra coil calcs seem to confuse many as well, there is a fair amount of information by Eric Dollard on the reasons and research behind the equations.

It starts from the point that the speed of light is due to the conjugate pair of E & B fields, now by rotating the B field by theta degrees it is possible to increase the velocity by cos(theta).

[jake]

@ jake

Is this what your circuit looks like?

I started with something very similar to that schematic. But then the ground line from the FWBR came off and it still worked fine with little to no difference. It actually worked better if I held the ground line instead of attaching it to the bottom of the secondary. That reminded me of an AV plug so I tried one and it worked, so I stopped using the FWBR.

The secondary has nothing attached to it except the soda can terminal and the ground. The soda can terminal is optional and the size can be changed to for more or less capacitance. I don't know exactly Eric recommends the can.

The primary has almost 2nF of capacitance attached to it. (6 silver mica in parallel) This will be replaced with a 2 plate capacitor. The LED and Piezo earpiece are both attached to the same AV plug. The piezo is in parallel with the LED on the AV plug. This can be touched to almost any part of the secondary or primary for a listen. It will start to pick up audio about 1" away from the coil.

If there is not enough capacitance on the secondary (not across), hand and body capacitance plague the system. You need to be near it to for it to work. Once I had enough capacitance I could approach without much issue but if I get with 1" it shuts down.

I went with the soda can on the secondary which gave me an SRF of ~2000kHz for the secondary alone. Adding the primary brought that down. Adding capacitance to the primary keeps bringing it lower. But there is a cost in efficiency.

Adding capacitors across the secondary was difficult because I needed so little capacitance. One lead from the top and one from the bottom laid close together was about as good as I could get. Or I could just hold my hand about 1 inch from the coil.

What did you use to draw the schematic?? I need something like that.

The question remains is this all related to TEM?

[xee2]

@ jake

Thanks for the update.

What did you use to draw the schematic?? I need something like that.

Download Serif DrawPlus

This is a free version.

[jake]

Uploaded with ImageShack.us

I'll get better at the schematics.

Thats what it looks like today. Replacing the can with 1 turn 1/2" copper tube made very little change. All of which could be offset by tube hight or capacitance on the primary.

[madhatter]

I finally finished the extra coil for the other set. So now I have two sets, one CW and one CCW.

Setting them up in series so that the two primaries are back to back and axial the entire series will resonate at 4Mhz, that took some fiddling.

disconnecting the extra coils and leaving them inductively coupled, and the two primaries inductive as well. setting about to tune the extras has been strange, the CW extra tuned easily enough, the CCW extra, nope. I've removed 3 turns got it as far as 3.5Mhz adding capacitance lowers it and I don't feel comfortable removing more turns. something odd with this setup.

For an experiment I fed the two primaries the same signal from the generator, so that signal goes to outer turn of CW and inner turn of CCW, opposite for ground lead. the secondaries are in series with a small capacitor and the free end has 7sq/in of aluminum foil as capacitance on it.

the extras are sitting horizontal so that the axis is vertical, they are sitting 45* off plane of the primary secondary axis at roughly 1.5" from the secondaries edge. top of each extra has 2sq/in of foil. the top of the CW extra is an LED with two diodes. The led lights brightly at 4.1Mhz, placing my hand anywhere near the secondary kills the light, near the extra has no effect. taking the LED circuit and placing it on a wooden dowel and moving about the entire arrangement the LED lights only when touched to the extra or secondary foil end. If I take the circuit and hold it via a plastic clip and move it about it will light when near the secondary free end or extra coils, my body capacitance seems to enable it to light wireless.

I'm only feeding it a 0dbm signal at .5vdc. CW extra coil measures ~3vdc wirelessly.

strange indeed. Oh and the magnetic field near the extra coils is lower then background field! very very weird.

[jake]

I finally finished the extra coil for the other set. So now I have two sets, one CW and one CCW.



Setting them up in series so that the two primaries are back to back and axial the entire series will resonate at 4Mhz, that took some fiddling.

disconnecting the extra coils and leaving them inductively coupled, and the two primaries inductive as well. setting about to tune the extras has been strange, the CW extra tuned easily enough, the CCW extra, nope. I've removed 3 turns got it as far as 3.5Mhz adding capacitance lowers it and I don't feel comfortable removing more turns. something odd with this setup.

Is there anything different about the coil form?

Is there any change in resonant frequency when you change the orientation?



For an experiment I fed the two primaries the same signal from the generator, so that signal goes to outer turn of CW and inner turn of CCW, opposite for ground lead. the secondaries are in series with a small capacitor and the free end has 7sq/in of aluminum foil as capacitance on it.

the extras are sitting horizontal so that the axis is vertical, they are sitting 45* off plane of the primary secondary axis at roughly 1.5" from the secondaries edge. top of each extra has 2sq/in of foil. the top of the CW extra is an LED with two diodes. The led lights brightly at 4.1Mhz, placing my hand anywhere near the secondary kills the light, near the extra has no effect. taking the LED circuit and placing it on a wooden dowel and moving about the entire arrangement the LED lights only when touched to the extra or secondary foil end. If I take the circuit and hold it via a plastic clip and move it about it will light when near the secondary free end or extra coils, my body capacitance seems to enable it to light wireless.

I see this happen as well. I am working on in.

I'm only feeding it a 0dbm signal at .5vdc. CW extra coil measures ~3vdc wirelessly.



How are you feeding it?

strange indeed. Oh and the magnetic field near the extra coils is lower then background field! very very weird.

Thats why you have to type words here without meaning

[xee2]

@ jake

The following test would provide a good measure of how well your crystal radio is performing. Find highest output voltage you can get with a specified antenna length.

[jake]

@ jake

The following test would provide a good measure of how well your crystal radio is performing. Find highest output voltage you can get with a specified antenna length.

It will show 2-3v avg. or 5-6v peak to peak if I set it up like that. No antenna. The digital multimeter and DSO nano average values are close.

BUT it needs to be grounded to something in my house or attached to my house, or "virtual grounded" to a copper plate on the counter. The entire electrical system including the mains ground and water pipes all are contaminated with the signal. i.e. I can faintly hear the station with just a diode and no coils..

Outside with a wire stuck into the ground away from the house I just get a signal of ~50mv. Without the wire in the ground I get nada.. ( I need to work on a good ground)

[jake]

Primary capacitor plate and lead

Its going to be dificult to solder this to the primary. I have two of these. The other is the mirror image.



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[xee2]

Its going to be dificult to solder this to the primary. I have two of these. The other is the mirror image.

Soldering is best, but just fastening with screws should work.

[xee2]

Outside with a wire stuck into the ground away from the house I just get a signal of ~50mv. Without the wire in the ground I get nada.. ( I need to work on a good ground)

Is this 50 mV with the resonator?

[dR-Green]

I think the secondary should be mostly left alone. It can be tuned for best signal by using adjustable condenser plates across it, and the primary also tuned using variable capacitors. One affects the other. This can all be seen on an oscilloscope across the primary. The plate connecting to the diodes "sucks" energy out of it and the voltage in the primary is lowered, also the plate itself affects the tuning so the condenser plates need to be adjusted to compensate. Using a simplified "power" setup with no load makes all this easily visible.

I also get a higher voltage in the primary at 1.4-2.something MHz when the station I'm tuning to is 882kHz, there's only noise at the higher frequencies/higher voltage, so I don't think just measuring the voltage is an accurate way of tuning it or any reliable way of determining what's going on. The signal should be in the primary otherwise there'll be no possibility of powering anything. The radio setup isn't arranged across the primary as a regular Tesla type receiver, rather in this case the primary is just having a resonant effect to maximise the "radiated" signal at the top of the secondary for reception through the plate antenna. In my opinion So I'd say the place to be looking is mostly at the primary.