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"3 Transistor" NON reflexed TRF receiver

Discussion in 'Electronic Projects Design/Ideas/Reviews' started by wcirco, Apr 29, 2010.

  1. wcirco

    wcirco New Member

    Joined:
    Apr 29, 2010
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    Location:
    Just outside of Annapolis MD
    Hello everyone,

    Im a vacuum tube guy but I decided to design and build a transistor radio for once. I didnt want to reflex and I really didnt want a regenerative set so I went for a TRF set. I came up with a high gain RF stage using a 2N3904 and I used the classic TL431 variable shunt regulator amplifier. It can be used for any wave band from 100khz to about 50mhz just with a change of the front end. I call it the "3 transistor" radio even though it only has 2 is because the TL431 looks like a transistor in its TO92 package.

    http://i770.photobucket.com/albums/xx347/wcirco/wcirco-2tran-1.png

    The 330pF cap is way too large, 33pF works better.

    Oh and the 1K pot is a screw driver adjust type, for setting the gain of the second RF stage to keep it from squealing.

    I built the radio with great success, Im listening to it as I type! I actually used a 1N270 instead of a 1N34A. Pretty much any small signal Germanium diode will work.

    I just wanted to see what you guys over at the electro-tech forums thought of it.

    Thanks,
    Wyatt
     
  2. Michael Justin

    Michael Justin New Member

    Joined:
    Aug 28, 2011
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    3 transistor radio

    I am very interested in building your transistor radio and would like to know the construction details of the tuning coil Gauge of wire and number of turns.

    Your help would be appreciated.

    Best regards michael
     
  3. TULLIO

    TULLIO New Member

    Joined:
    Aug 18, 2008
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    Regenerative receiver

    Hello Michael Justin: see: neo teo receptor regenerativo,with pcb .
     

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