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Eric's "Crystal Radio Initiative" Challenge

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  • Jeff Pearson
    replied
    ground here is dry sandy clay. I pounded a 4ft piece of rebar for a ground to start with. Then I tried my roof. I am building a concrete dome on top of rammed earth walls. There is a 3ft piece of rebar every 30 inches driven into the rammed earth walls to connect the bond beam to the metal skeleton of the roof. The CRI coil and the crystal radio both work better using this for ground than a standard ground rod. I have not made an actual ground plane yet but I do have the room to do so. the rammed earth walls are a 20ft diameter on the inside circle and the walls are about 30inches thick so the connection to earth is good as far as surface area goes

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  • Jeff Pearson
    replied
    CKLW is a 50,000 watt, Class B, AM radio station . Is this the station your trying to pick up and have you done any receiving yet LeeBob. The local station I built for only puts out a thousand watts. I think maybe I could do pretty good by taking it to town and connecting to a fire hydrant for ground.
    Attached Files

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  • LeeBob84
    replied
    Originally posted by Jeff Pearson View Post
    Also, there is about a thousand foot deep rift in the earth between here and town "Rio Grande Gorge" I wonder what that does to the ground signal. I'm gonna have to take it to the other side of the Gorge and do testing there also
    What is your ground?

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  • LeeBob84
    replied
    CRI Update

    Woo Hoo I won the CRI

    Just want to throw out a special thanks to Aaron and Eric for the "Crystal Radio Initiative". It has been a time consuming build but very educational for me. Also a shout out to the annonymous donor of funds for the CRI Challenge. The funds are going to good use on the build.

    I have now finished the extra coilIMG_0719.jpg and have added a precision adjustor to my capacitorIMG_0717.jpg IMG_0718.jpg Lol. Crude but effective. This is the beast with the extra coil and new toploadIMG_0716.jpg. I have pounded my holes in the grounding and am just waiting to receive funds for the aluminum to fill themIMG_0720.jpg. I have also decided that instead of using the 4awg copper, i am going to dig a thin trench about 12" deep and pour aluminum between all holes. I will also be pouring an extra eight holes in addition to these in the same pattern only 10 feet out. Also connected the same way. I am hoping i can get about 200lbs+ of aluminum in the ground. This should be effective as a good grounding system for now.

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  • Jeff Pearson
    replied
    Also, there is about a thousand foot deep rift in the earth between here and town "Rio Grande Gorge" I wonder what that does to the ground signal. I'm gonna have to take it to the other side of the Gorge and do testing there also

    Leave a comment:


  • Jeff Pearson
    replied
    CRI coil for 1340Khz Kvot

    Corrected 1/4 wavelength= 142.25 ft.
    using .7752 correction factor. 102% velocity factor X 76% burden factor.
    I avoided all rounding till the end
    Length per turn= 85.35 inches
    At this point I figured for an octagon instead of a circle since my coil form is an octagon and I'm trying to be as accurate as possible so I calculated 10.67 inches per facet of octagon
    Diameter of circle would be 27.18 inches
    Height= 5.44 inches

    The tuning seems to be right on. With topload and ground connected I can hear the radio station clearly through a regular crystal detector consisting of a germanium diode, demodulation capacitor, load resistor and crystal earpiece. It makes noise but unintelligable with no ground or top load.
    At the moment the detector is connected across the secondary. I put together a simple amplifier using a LM386 IC driving a piezo element.
    With the amplifier 1340Khz comes in clear with the secondary connected to nothing. When I add the top load the signal gets a little bit stronger and when I connect the ground the signal gets a lot stronger. I have tuned it up to 1510Khz by tapping the top load at the 16th or 17th turn. And I have accidentally tuned it down to 950Khz by adding a long ground wire one day when I didn't want to carry it out to the ground rod.
    That's what I have done for testing so far. Oh and I did put a temporary primary on it with variable capacitor. There is a sweet spot where it raises the power of the secondary. Getting ready to rewind the whole thing. I am happy with the frame. More appropriate wire for the secondary and some 4 inch wide copper flashing for the primary coming soon.

    Great Looking coil Leebob.

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  • LeeBob84
    replied
    CRI Update

    Did some calculating for my capacitor and have built a fairly crude looking but hopefully effective capacitor.IMG_0705.jpgIMG_0706.jpgIMG_0707.jpgIMG_0708.jpg The size of plates and how many is based on surface area of the secondary coil windings surface area. I calculated the surface area of the entire coil and adjusted my primary as well IMG_0709.jpgIMG_0710.jpg so that the surface area of all 3 components is within 100sq/in of eachother. This hopefully will cause the coil to resonate better. Also I have got the material now for the extra coil so I will be starting work on it next. This coil will be 1'6" tall and wide, it is a 1:1 ratio coil. Coil will be 90 turns with a wire length of 439'4" and close to 10awg so that is what i am going to use. Also I am changing my topload, The copper hemisphere I have built could possibly cause what looks like a dead short in the coil so i will be replacing it with 2 Toroids made from 6" aluminum foil ducting which will be capped with an insulator on each end to prevent this dead short in the coil.The big toroid will be around 3 ft in diameter and the smaller will be around 2 ft.

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  • LeeBob84
    replied
    Originally posted by Jeff Pearson View Post
    Did the calculations for this in January finally building it. 1340Khz. 3/4 inch tubing would be close to the ideal conductor but winding it with what I got right now. I think its 20awg
    Nice work

    So i guess there is someone else out there who is doing this.. I was beginning to think I was the only person working on this

    Best part is the way my neighbors look at this 5ft tall 4 ft diameter coil in my back yard. Some think its a chicken coop, some think its a fort for my kids, and I'm sure there are a few who think its some sort of ufo landing pad lol ... So far I have only met one person (in person, not on the net) who actually appreciates what this is actually designed for, and kinda understands what I'm talking about when I try to explain it, and he is an old military guy.

    Hope u keep posting updates here. Will be nice to have someone to bounce ideas off of who is building one too.

    Leave a comment:


  • Jeff Pearson
    replied
    Did the calculations for this in January finally building it. 1340Khz. 1/8 inch tubing would be close to the ideal conductor but winding it with what I got right now. I think its 20awg
    Attached Files
    Last edited by Jeff Pearson; 07-07-2016, 06:05 PM.

    Leave a comment:


  • Aaron
    replied
    cri

    Originally posted by LeeBob84 View Post
    Wow that is awesome thanks Aaron.I have the primary and secondary windings wound, and have been trying to get a good ground system put in. I am living in a rental house at the moment so my original idea of digging four large holes with radiators buried in the yard is a no go. So i have come up with the idea of pounding holes about 4 to 6 feet deep with a 1 inch piece if pipe then removing the pipe, feeding a piece of 4 gauge copper wire to the bottom and pouring molten aluminum down the holes till they are full. I have finally completed mt foundry and poured about 3 pounds of aluminum in the first hole. My biggest hold up now is trying to come up with funds to buy scrap aluminum and fuel for my foundry. I figure that i will need a total of about 75 pounds of aluminum and probably 100lbs of propane to finish. Any Help with that would be more than appreciated. Also I am in need of a good adjustable capacitor for this project to.
    [ATTACH]17235[/ATTACH][ATTACH]17236[/ATTACH][ATTACH]17237[/ATTACH][ATTACH]17238[/ATTACH][ATTACH]17239[/ATTACH][ATTACH]17240[/ATTACH]
    Thanks again
    Let me know
    Please email me at info at emediapress dot com and copy and paste your message here to me - I can help.

    Leave a comment:


  • LeeBob84
    replied
    Originally posted by Aaron View Post
    The recording is on his site embedded as a youtube video.

    What do you need to finish your project in terms of parts and funds?
    Wow that is awesome thanks Aaron.I have the primary and secondary windings wound, and have been trying to get a good ground system put in. I am living in a rental house at the moment so my original idea of digging four large holes with radiators buried in the yard is a no go. So i have come up with the idea of pounding holes about 4 to 6 feet deep with a 1 inch piece if pipe then removing the pipe, feeding a piece of 4 gauge copper wire to the bottom and pouring molten aluminum down the holes till they are full. I have finally completed mt foundry and poured about 3 pounds of aluminum in the first hole. My biggest hold up now is trying to come up with funds to buy scrap aluminum and fuel for my foundry. I figure that i will need a total of about 75 pounds of aluminum and probably 100lbs of propane to finish. Any Help with that would be more than appreciated. Also I am in need of a good adjustable capacitor for this project to.
    IMG_3886.jpgIMG_3887.jpgIMG_3888.jpgIMG_3895.jpgIMG_3889.jpgIMG_3890.jpg
    Thanks again
    Let me know

    Leave a comment:


  • Aaron
    replied
    Crystal Radio Initiative

    Originally posted by LeeBob84 View Post
    Thanks Aaron,
    Unfortunatlly I missed that call with Eric, Where would I be able to listen to the recording of the call?

    One question I did want to ask him was about using a ribbon conductor supposed to the traditional round wire conductor and if there were significant differences calculating for it?
    The recording is on his site embedded as a youtube video.

    What do you need to finish your project in terms of parts and funds?

    Leave a comment:


  • LeeBob84
    replied
    Originally posted by Aaron View Post
    That's great LeeBob!

    If you have any questions for Eric, we have a live call tomorrow:
    This coming Sunday the 27th at 11AM Pacific Daylight Savings Time, we will be having a LIVE Q & A call with Eric Dollard.
    Conference Dial-in: 1-857-232-0155 and Conference Code: 582590 – It will be recorded in case you cannot make the call.
    Thanks Aaron,
    Unfortunatlly I missed that call with Eric, Where would I be able to listen to the recording of the call?

    One question I did want to ask him was about using a ribbon conductor supposed to the traditional round wire conductor and if there were significant differences calculating for it?

    Leave a comment:


  • Aaron
    replied
    Live call with Eric

    That's great LeeBob!

    If you have any questions for Eric, we have a live call tomorrow:
    This coming Sunday the 27th at 11AM Pacific Daylight Savings Time, we will be having a LIVE Q & A call with Eric Dollard.
    Conference Dial-in: 1-857-232-0155 and Conference Code: 582590 – It will be recorded in case you cannot make the call.


    Originally posted by LeeBob84 View Post
    I have been working on a large coil for the crystal radio initiative. This is a few pics of it
    [ATTACH]16937[/ATTACH]

    [ATTACH]16938[/ATTACH]

    Frequency : 800khz
    Coil diameter:4'10"
    Number of turns: 18
    Wire length : 247'
    Coil height:14.4"
    Wire diameter : 0.5"

    I made a hemisphere from copper pipe, with a 16 point aluminum star as my top load. All that is left is to bury my 4 a/c radiators as my ground, wrap a 12" by 2 turn secondary coil on the bottom and build my resonant capacitor. Hopefully I can tune it up to receive some usable energy. U can follow me https://youtu.be/HyRhUStqzt4 , https://youtu.be/jncwulYUpV4

    Leave a comment:


  • LeeBob84
    replied
    Crystal radio initiative

    I have been working on a large coil for the crystal radio initiative. This is a few pics of it
    image.jpg

    image.png

    Frequency : 800khz
    Coil diameter:4'10"
    Number of turns: 18
    Wire length : 247'
    Coil height:14.4"
    Wire diameter : 0.5"

    I made a hemisphere from copper pipe, with a 16 point aluminum star as my top load. All that is left is to bury my 4 a/c radiators as my ground, wrap a 12" by 2 turn secondary coil on the bottom and build my resonant capacitor. Hopefully I can tune it up to receive some usable energy. U can follow me https://youtu.be/HyRhUStqzt4 , https://youtu.be/jncwulYUpV4
    Last edited by LeeBob84; 03-27-2016, 01:57 AM.

    Leave a comment:

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