Due to demand I have designed an Amplitude Modulated Shortwave Transmitter outputting roughly 4Watts on a desired frequency set by the crystal between 5.5MHz and 10.24MHz. All capacitors are ceramic type. I used fixed mini-presets but you can use external POTS for the Mic/Mixing controls (Use Preset in the emitter circit). The transmitter can be used for AM voice purposes on the HAM band. If you require to use this circuit for music broadcast, the mic pre-amp stage can be missed out and the output from a mixer or tape recorder coupled directly. On the 7MHz Amateur Band over 160 miles have been acheived using a 40mtr Wire Dipole antenna. The 22pF trimmer aligns the frequency and the coils and 47pf trimmer tunes for maximum output. It is Ideal to tune up this circuit using a wave detector meter placed a few inches away from the transmitter. I have a circuit on this site.
This page was updated on 22nd November 2000.