Archive for the Category


15W Fm-transmitter

Tuesday, January 22nd, 2008


It was five years ago when I did an attempt to build my first fm-transmitter. It ended in a giant faillure. The only thing it did was interferring with our tv-set. Looking back it was due to the lack of information I had. A schematic was my only help. Now, five years later, I know [...]

V7 VHF FM Transmitter by 2N3866

Tuesday, January 22nd, 2008


The circuit is identical to the V7 VHF FM Transmitter but with a few small additions. TR1 (BC547) is an inverted Hartley oscillator which based upon an inductor fabricated on the PCB. This makes it megga-stable, and setable anywhere in the VHF FM band (76MHz to 119MHz) and the BB105 varicap makes it voltage tuneable [...]

FM TRANSMITTER one Transistor by 2N3564, 2N5225

Monday, January 21st, 2008


A truly minimalist circuit. Performance is relatively poor and stability is a problem. Q1 modulates the signal and acts as an oscillator. L1 and C5 determine the frequency. Decrease C5 for a higher frequency and vice-versa.
You won’t get a long range transmission with this one. The author claims 50-500 feet. A lot depends on the [...]