Sunday, December 23, 2012

Happy Birthday... the transistor...

...and to myself.. (a little bit younger than the transistor)... taken some years ago on a field day

To celebrate the event and the "end of the world" :) this week I built an VFO with my age...

...from 73 Magazine, December 1972 (p114). It worked first time, although I just built the VFO part (Q1,Q2,Q3) there's no reason the buffer/amp part wouldn't work either. The design in itself is very interesting on the Q1 bias part, which is provided by Q3 to keep a constant output level.
As always I changed things a little bit, used 2n3904 transistor but almost any other transistor would work, with the exception on the one of the first photo in this post :)

Season greetings!


PE4BAS, Bas said...

Congratulation Ricardo with your birthday. Merry Christmas and a happy new year! 73, Bas

Ricardo - CT2GQV said...

Hello Bas,

Thank you!

73, Ricardo