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  1. C

    Variable Capacitor

    Thanks a ton for the response. Just to double check I am thinking of this correctly: A wire goes from A to O. Then a wire from O tp the circuit. ( this is connecting them in parrell, or did you mean in series? ). Then a wire from G to the circuit.  This gives me the 220pf? So I would have...
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    Variable Capacitor

    So is that a wire from O to A and then a wire from A to the circuit and a wire from O to the circuit, and dis-regard G all together? Sorry, I am new to this! In my mind I see a wire from A to the circuit and G to the circuit gives me 160 O to the circuit and G to the circuit gives me 60 A to...
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    Simple AM receiver

    I am using a transistor from a pack of common NPN-Type switching transistors. I do not have the exact model. The are probably like the MPS2222A transistors. I swapped out the transistor for another one and got the same voltage readings and same results to the speaker. I will post more on the...
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    Simple AM receiver

    Hey Guru Plz Help, I built the AM receiver circuit and fed the output to the "'AM Radio Power Amplifier" on the LM386 datasheet. I have everything hooked up except I am not using "ferrite beads" on the output of the LM386. I actually get a Radio Station around 900AM, but the sound is VERY VERY...
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    Variable Capacitor

    Can someone please explain the leads of this variable capacitor and how to hook it up? I have never used one and I want to make sure I get this correct. Thanks -crivoli
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    Simple AM receiver

    My question is if I build this simple AM receiver and feed the output to the LM386 using a gain of 50, should the output to the speaker be good quality audio? I saw the datasheet for the LM386 and it shows an "AM Radio Power Amplifier" schematic, but can I use one of the other setups without...
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    audioguru, question on preamp/amp

    i believe I solved this problem with your help... Thanks a ton. I seperated the mic and speaker and I also changed somve values of what I was using. Please check my other post on a "Simple AM receiver" Thanks again.
  8. C

    audioguru, question on preamp/amp

    Question 1: I built the circuit on the LM386 datasheet with the amp at a gain = 20. Everything works fine. I then adjusted the gain to 50 and it works correctly. When I adjust the gain to 200 the speaker just squeals horribly. I have built this circuit before and used a gain of 200 with no...
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    FM Transmitter

    I was going to use alligator clips :)  Just wanted to make sure this wouldn't throw anything off. Thanks again
  10. C

    FM Transmitter

    The designer of the AM ciruit said he built this on a breadboard. Any idea how to hook up a variable cap on a breadborad since the connectors don't fit?
  11. C

    FM Transmitter

    So am I able to replace the coil and tunning capacitor in the schematic with any coil and tunning capacitor I find that are compatable with each other? Thanks
  12. C

    FM Transmitter

    So, I could be safe in replacing those components of the schematic with those I found on e-Bay. Does that sound right? Also, on the transmitter schematic it is not clear of what L1 is: http://www.electronics-lab.com/projects/rf/011/index.html Is it another ferrite coil, or magnet copper wire...
  13. C

    FM Transmitter

    audioguru, No I didn't realize that. How then on that schematic is the antenna a 220uH and the resistor is a 500pf? Do you have to tune the capacitor until it reaches the matching value?
  14. C

    FM Transmitter

    The AM receiver schematic specifies a 500pf variable capacitor. The one  on E-bay is 60/160pf. Do you think that will work, or will I need to change values of other coponents on the schematic?  Thanks
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    FM Transmitter

    audioguru: I appreciate your patience with me. Would this work for the am receiver as the 220uH component? http://cgi.ebay.com/Ferrite-Loopstick-Antenna-Coil-Crystal-Radio-Radios_W0QQitemZ6619389741QQcategoryZ7275QQssPageNameZWD1VQQrdZ1QQcmdZViewItem also I can not seem to find any good...
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    FM Transmitter

    I agree it does not specify the range, but this 'should' work in my scenario correct? I don't want to try them if they are not useful to me. If you think they will work for my project I will give them a shot. I would builf the receiver first to see if I could get AM stations on it. Why...
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    FM Transmitter

    audioguru: I found an AM transmitter and AM receiver on the project page: http://www.electronics-lab.com/projects/rf/006/index.html  -- Receiver http://www.electronics-lab.com/projects/rf/011/index.html  -- Transmitter Would this work in my scenario to send audio through a mic across my...
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    FM Transmitter

    Well, I guess I set myself up for that one!! I have already made the amplifier circuit I wish to send the audio too. I was looking for a simple transmitter/receiver for this project but I am not finding anything. I guess a 49Mhz walkie talkie schematic may do the trick but they seem impossible...
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    FM Transmitter

    Well, seeing as how I am obviously NOT an expert ( yet :) ), is there any practical solution for sending audio wireless to a receiver that I could either make myself or obtain from some other  reasonable source
  20. C

    FM Transmitter

    I am wanting to transmit voice from a mic to a receiver that would amplify it out of a speaker. I assume this can be done with a 27MHz signal, am I wrong? I found some schematic here, can you tell if they work: http://jap.hu/electronic/rf.html I can't really read them very well...... can you...
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