ARRL HB CHP25 FIG.51 (88-91) AND CHP25 FIG.39(>93)
Description: The project is designed to supply two tones of equal amplitude for linearity testing of an SSB transmitter. The frequency of the tones are set at 700 Hz and 1900 Hz. Two Wein bridge oscillators using LF353N dual J-FET op-amps generate the tones. Three op-amps are used.
Description: The project controls one relay from a 3 digit DTMF code that is programmed into a 27C64 EPROM. The programming is simple and only uses the first few bytes. The three digit code plus * closes the relay and then the # opens the relay. Project uses an MT8870 DTMF Decoder, a 27C64, 74LS08, 74LS04, AND 2-74LS74's.
PROGRAMMED EPROM AND PC BOARD
Description. Complete information at www.alblas.demon.nl/wsat/hardware/dec_pcb.html Project uses two XC3042P84-70 processors 514256 and 27C512(supplied with the board programmed) For additional information contact Rob at email@example.com