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.
https://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
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.
https://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