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Eric's "Crystal Radio Initiative" Challenge

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  • Sebacid
    replied
    Would you agree that the smaller the acrylic clear and hollow tubes the better?

    Leave a comment:


  • dR-Green
    replied
    "Total number of turns = 20" means exactly what it says. 20 turns in total on the coil.

    The 20% is in reference to the height/length to diameter ratio of the coil. The coil is 20% high as it is wide. If diameter = 100cm then height = 20cm.

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  • parkham
    replied
    I hope this isn't a completely question - When he says "Total number of turns", Given 20 - what does he mean by 20? Would that be 20 turns per inch?

    The same for the next formula, "Given 20%" What exactly does that mean as well?

    Please pardon my ignorance. I've got all the components together to start on a crystal radio - I want to fully understand before proceeding though.

    Thanks,

    Leave a comment:


  • Jeff Pearson
    replied
    I was experimenting with crystal sets last year
    Was listening to clear channel stations 2 states away at night with crappy antenna. Powered piezo headset i made. no power source for radio except radio waves. I learned a lot doing this. was gonna try ground antenna next Harris Rogers style.
    Attached Files
    Last edited by Jeff Pearson; 08-01-2014, 07:07 PM. Reason: fix picture

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  • orgonaut314
    replied
    Originally posted by Sebacid View Post
    Does it matter if I use insulated wire for the winding? Or is it better if it was copper?
    Every insulation will increase the self capacitance. Now I think it was better to keep that one low as possible.

    Apart from that be careful with the material you use. If there is Orgon than organic materials like wood or materials like coper are preferable. In another type of research we found out that Orgon does become sickening if you use the wrong materials that your body does not like when you would eat or drink them. I would be careful with pvc that contains chlore. Even the thin insulation on the coper wire might be wrong. But this is only important if you want to make a coil that does not make people get an head-age.

    Leave a comment:


  • Sebacid
    replied
    Wire?

    Does it matter if I use insulated wire for the winding? Or is it better if it was copper?

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  • Sebacid
    replied
    Originally posted by wayne.ct View Post
    Correcting my error and still using 750 KHz as my center frequency, this is what I get...

    Calculation #1

    L = Total length of coiled wire

    L = c/w = 299,792,458 (meter / second) / 2 * PI * 750,000 (/second)

    = 299,792,458 / 2 * 3.14159 * 750,000 (meters) = 63.62 meters = 63.62 meters / .3048 (meter / ft)

    = 208.7 feet

    Calculation #2

    L = Length of each turn = 208.7 feet / 20 = 10.44 feet = 10 feet 5.23 inches

    Calculation #3

    Circumference C = L; Diameter = Circumference / PI = 3.32 feet = 3 feet 3.86 inches

    H = Coil height = 0.2 * Diameter = 0.2 * (10.44 feet / PI)

    = 7.97 inches

    Calculation #4

    Max diameter of wire. Space between strands of wire is 62 percent of wire diameter.

    20 turns take 7.97 inches ===> 1 turn takes 7.97 inches / 20 = 0.4 inches

    0.4 inches = 162 percent of wire diameter ===> 100 percent of wire diameter = 0.4 / 1.62

    Wire diameter = 0.246 inches (max.)

    AWG 3 has a diameter of 0.2294 inches / 5.83 mm.

    AWG 3 has resistance of 0.646 ohms / Km. which is 0.197 mOhms / ft.

    For 208.7 ft, the coil will have 395 mOhms or 0.4111 Ohms resistance.

    Now we have a manly sized inductor! 'Sorry to say I will not be building that any time soon! Thanks for the ride!

    At the same time, my intuition was telling me this was going to be a large coil. So, I feel a bit better knowing my gut was in the ballpark.
    You can always use another frequency (higher), then the coil, wire etc. size will be smaller. Try for something in between 2000-3000Kc/sec? As Dr. Green said earlier, the idea is to magnify the chosen frequency to the max!

    Don't give up, build a smaller one first, experiment on it and if succesfull, upscale it on the next one!

    Cheers,

    -Seb

    Leave a comment:


  • wayne.ct
    replied
    This is out of my league

    Correcting my error and still using 750 KHz as my center frequency, this is what I get...

    Calculation #1

    L = Total length of coiled wire

    L = c/w = 299,792,458 (meter / second) / 2 * PI * 750,000 (/second)

    = 299,792,458 / 2 * 3.14159 * 750,000 (meters) = 63.62 meters = 63.62 meters / .3048 (meter / ft)

    = 208.7 feet

    Calculation #2

    L = Length of each turn = 208.7 feet / 20 = 10.44 feet = 10 feet 5.23 inches

    Calculation #3

    Circumference C = L; Diameter = Circumference / PI = 3.32 feet = 3 feet 3.86 inches

    H = Coil height = 0.2 * Diameter = 0.2 * (10.44 feet / PI)

    = 7.97 inches

    Calculation #4

    Max diameter of wire. Space between strands of wire is 62 percent of wire diameter.

    20 turns take 7.97 inches ===> 1 turn takes 7.97 inches / 20 = 0.4 inches

    0.4 inches = 162 percent of wire diameter ===> 100 percent of wire diameter = 0.4 / 1.62

    Wire diameter = 0.246 inches (max.)

    AWG 3 has a diameter of 0.2294 inches / 5.83 mm.

    AWG 3 has resistance of 0.646 ohms / Km. which is 0.197 mOhms / ft.

    For 208.7 ft, the coil will have 395 mOhms or 0.4111 Ohms resistance.

    Now we have a manly sized inductor! 'Sorry to say I will not be building that any time soon! Thanks for the ride!

    At the same time, my intuition was telling me this was going to be a large coil. So, I feel a bit better knowing my gut was in the ballpark.

    Leave a comment:


  • dR-Green
    replied
    Originally posted by Kokomoj0 View Post
    for accurate time comparison how do you compensate and adjust for delay differences that result from the inherent design differences between the telluric and atmospheric versions?
    Use an oscillator and tune both receivers to be in phase.

    Originally posted by Kokomoj0 View Post
    how do we calculate the maximum theoretical (ideal conditions) power that can be drawn from a transmitter with a particular receiver design/situation
    Beats me. How's your geological skills?

    Leave a comment:


  • Kokomoj0
    replied
    for accurate time comparison how do you compensate and adjust for delay differences that result from the inherent design differences between the telluric and atmospheric versions?

    and one more....

    how do we calculate the maximum theoretical (ideal conditions) power that can be drawn from a transmitter with a particular receiver design/situation
    Last edited by Kokomoj0; 08-30-2013, 05:48 PM.

    Leave a comment:


  • dR-Green
    replied
    I forgot to mention, use white or clear etc plastic rods. Apparently to make black and grey they put carbon in it, so that won't be good.

    Eric's design is different to Tesla's. Eric's theory involves concatenated resonance with the extra coil as a distributed network, whereas Tesla's is lumped. So it's completely experimental. I've tried 3 different extra coil variations, and Eric's latest comments on it was that the secondary might need to be of a lower inductance, so my latest design is a bit different. I have 17 turns secondary with 15% height to diameter ratio, and the extra coil, when calculating wavelength from frequency and speed of light, has 1.19 times longer wire length because of the "faster than light" propagation, wire length is extended to bring the frequency back down.

    [edit] Probably the easiest way to find whether a radio station is operational and suitable or not is to use a radio. When you find one then you can find info on it on the internet.
    Last edited by dR-Green; 08-30-2013, 01:57 PM.

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  • Sebacid
    replied
    Originally posted by dR-Green View Post
    Hi Sebastian. Yes PVC tubing will be better than wood. Also ideally you should design the coil for a specific frequency/radio station, 1000 kc is a general example. When tuned to different frequencies the magnification factor will alter, the goal is to have highest magnification factor at the intended frequency so different tuning will work against this. Although you will need to experiment to find the highest magnification factor with a given design anyway.

    For the overground wave reception you should use a normal crystal radio or a normal radio receiver. You need to receive the signal as normal and then measure the difference.
    Hi Dr. Green,

    Thank you for your insight, I will have to do some searching on a AM radio station near me (Finland). The problem here is that almost all of the broadcasting stations have ceased using the AM frequencys. I think the nearest one is in Holland?! Not sure on this, must check.

    In the calculations for the extra coil, I get a totally different total lenght of coil if I use the formulae by Eric to calculate it?

    Tesla's Colorado extra coil had the same amount of wire as the secondary (800m). Should I go with this or trust the formulae?

    Thanks again,

    -Seb

    Post edit:

    Found a radio station from Sweden, Stockholm radio that broadcasts at 1710Khz AM frequency. I think it is still operational, so I will try working with this frequency. The last AM radiostation in Finland ceased to operate in 2007. Any other known operational frequencys are welcome!
    Time to do the calculations again!
    Last edited by Sebacid; 08-30-2013, 12:55 PM. Reason: Adding information

    Leave a comment:


  • dR-Green
    replied
    Hi Sebastian. Yes PVC tubing will be better than wood. Also ideally you should design the coil for a specific frequency/radio station, 1000 kc is a general example. When tuned to different frequencies the magnification factor will alter, the goal is to have highest magnification factor at the intended frequency so different tuning will work against this. Although you will need to experiment to find the highest magnification factor with a given design anyway.

    For the overground wave reception you should use a normal crystal radio or a normal radio receiver. You need to receive the signal as normal and then measure the difference.

    Leave a comment:


  • Sebacid
    replied
    Originally posted by Sebacid View Post
    Just finished my calculations for my secondary coil and it will be a whopping 76cm in diameter! I am going with 1000Kc/sec Frequency.

    I finished the work on the wooden bases and supports, all that is left is to bake and laquer them before assembling.

    My extra coil's diameter/height is going to be 30cm.

    Some calculations with other stuff is still going on, but I'm going to build two identical coils of the exact same size, one for overground Hertzian wave reception and the other for underground Tellurical wave reception.

    The coils will be identical but the setup will be different as the goal is to light a 100W lightbulb with the other coil.

    We'll see how things go once I have built them.

    -Seb
    Thinking of replacing solid wooden supports, with hollow pvc tubing (thin) to minimize stray inductance? Any thoughts on this?

    Leave a comment:


  • Sebacid
    replied
    Just finished my calculations for my secondary coil and it will be a whopping 76cm in diameter! I am going with 1000Kc/sec Frequency.

    I finished the work on the wooden bases and supports, all that is left is to bake and laquer them before assembling.

    My extra coil's diameter/height is going to be 30cm.

    Some calculations with other stuff is still going on, but I'm going to build two identical coils of the exact same size, one for overground Hertzian wave reception and the other for underground Tellurical wave reception.

    The coils will be identical but the setup will be different as the goal is to light a 100W lightbulb with the other coil.

    We'll see how things go once I have built them.

    -Seb

    Leave a comment:

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