College Papers

What the farther the radio was moved from

What is the Range of a Crystal Radio?Julia LardinSkinner North Abstract 2What is the Range of a Crystal Radio 3Method 3Participants 3Assessments and MeasuresProcedure 3Results 5Outcome 1 5Outcome 2 6Conclusion 6ReflectionApplicationAcknowledgements 7Bibliography                                                                                                                                   8AbstractI am trying to find what the range of a crystal radio is.  The problem was that crystal radios cannot be transported well because of the ground circuit.  To test this, I built the radio and drove to different places trying to find out when the signal would disappear.  I found that it only takes about 20 miles to lose the signals.  Overall, my hypothesis was correct. Radios are some of the oldest electronic devices.  The simplest form of a radio is the crystal radio, an AM radio with only a few parts.  Crystal radios were used in the early 1900s, working better than any other radios at the time.  They were used for family entertainment, a type of modern T.V., but crystal radios have no amplifiers and weak signals, so they were kind of hard to use.  The goal of my project was to test how far the range of a crystal radio is.  I guessed that the farther the radio was moved from the transmitter, the weaker the signal would be because of many pieces of background knowledge that I thought of.  For example, transmitters and crystal radios are like say, phones and wifi.  If one moves too far away from the wifi transmitter, you will lose the signal.  I thought of it like that, but in a grander scheme because AM radio can  My hypothesis was that the crystal radio can only get about 100, maybe 140 miles away from the transmitter withoutMethodParticipantsI did not have actual test subjects for this, seeing as that is unnecessary, but my father did help me.  He gave me advice for how to place the pieces together to make the radio, but other than that, no one else participated.Assessments and MeasuresTo measure the distance, I used a GPS to tell me how far I was from the transmitter.  I also used a multimeter to measure the energy from the capacitor and the ground energy.  To actually go somewhere, we used a car and drove far away to see how far the radio could go without disconnecting from that station.To do this project, I only needed a few materials.  I needed a wooden board to put my radio on, a capacitor to search for a station, a diode that makes the electrons go in one direction, but still lets some go through to reach the erbud, a piezoelectric crystal earbud, a lot of wires, alligator clips, an antenna, an outlet, and a tuning coil with an iron rod in the center.To do this, there were piece. This is a schematic of a simple crystal radio and how everything fits together. ResultsWe got a couple of results from our various test spots.  Most of them were about 1 or fewer miles away, so I am assuming that their radios signal as extremely weak because our second destination was barely hearable from the radio.Outcome 1 At my house, I could hear many channels and only one of them I could hear from skokie.  There were a lot of stations and almost all of them I could hear clearly and identify.  Some of them were ESPN, WGN, andOutcome 2 From skokie I could hear three stations and could identify only one.  I heard the radio say WGN, and that was one I could hear from Chicago.Outcome 3 At a church on Division street, I could hear multiple stations, almost better than from my home.  I heard ESPN, and a few other stations I was unable to identify because some were in other languages or I could not hear it well. Conclusion My science fair project was about the range of crystal radios and how far it can go from the transmitter without losing the signal.  I hypothesised that the crystal radio could not get more than about 100 miles away from the transmitter without falling out.  My hypothesis was sort of correct because I could not get ones had the sameReflectionI think my test was mostly fair.  To improve my test, I could have added another capacitor to make the signal smoother, I could have found a better way to measure the distance, I could have spent more time on trying to find a signal and trying to identify the station and go through every station available in the Chicago area and try to match those with what I heard on the radio.  Now like to try just driving around and seeing how good the signal is and finding the exact point at which the signal fades.  Another thing I would like to further investigate is how this thingApplicationThis experiment could the electromagnets and other electric things like diodes and piezoelectric crystals work.   Acknowledgements Thank you to my dad who helped by build this, to my mom, who bought the materials, to the people at Peapod for letting me get in their building, and to the people at HTOC for letting me test in their building.BibliographyCrystal Radio Schematic Crystal Radio Schematic. (n.d.). Retrieved November 20, 2017, from (Director). (2012, February 17). How to build a crystal radioVideo file. Retrieved November 11, 2017, from cU9 ULAlARimstarorg (Director). (2012, August 30). How a crystal radio worksVideo file. Retrieved November 11, 2017, from matEE. (n.d.). How Does a Crystal Radio Work. Retrieved November 20, 2017, from, October 23). Retrieved November 20, 2017, from crystal radio circuit Basic crystal radio circuit. (n.d.). Retrieved November 13, 2017, from vs FM. (n.d.). Retrieved November 20, 2017, from and FM Radio Frequencies. (n.d.). Retrieved November 20, 2017, from (n.d.). Is AM Radio Still Relevant? Retrieved November 20, 2017, from Retrieved November 20, 2017, from