has anybody ever experimented with 73khz?
we need a NOV to allow us the permission to do it properly but i have played with it a little years back,
i used my sig gen dialed to 73khz and modulated the vco with a cd player, feeding that into a car amplifier that produced way less than its 100w per ch rating on 73khz,
i never used anything larger than a piece of wire draped around the furnature as an antenna because 73khz fm is naughty to say the least and i wanted to ensure nobody else would hear what i was doing
i set deviation low and managed to transmit crystal clear mono audio from the house to the car in the yard about 40-50yards away,
im sure i was transmitting further but i did not think an inverter would be any good to power a 73khz receiver away from the mains due to the rf garbage switchmode psu's and inverters spew out over the lf through hf bands, the fields were wet and i was not gonna risk getting stuck in a muddy field to see how far it was working,
i ran a mains extension to the car from the tractor shed and used my yaesu ft767 as the receiver ( the only hf set i had that would receive right down to the 50hz mains hum ).
the idea of 73khz fascinated me from the day i saw a pic of a ham with a coil wrapped on a 60 gallon plastic drum with wooden spacing lats and hundreds of feet of longwire antenna complaining that his antenna was so small its efficiency was extremely low,
his dream was to have several thousand meters of wire strung out over the fields behind his house.
we need a NOV to allow us the permission to do it properly but i have played with it a little years back,
i used my sig gen dialed to 73khz and modulated the vco with a cd player, feeding that into a car amplifier that produced way less than its 100w per ch rating on 73khz,
i never used anything larger than a piece of wire draped around the furnature as an antenna because 73khz fm is naughty to say the least and i wanted to ensure nobody else would hear what i was doing
i set deviation low and managed to transmit crystal clear mono audio from the house to the car in the yard about 40-50yards away,
im sure i was transmitting further but i did not think an inverter would be any good to power a 73khz receiver away from the mains due to the rf garbage switchmode psu's and inverters spew out over the lf through hf bands, the fields were wet and i was not gonna risk getting stuck in a muddy field to see how far it was working,
i ran a mains extension to the car from the tractor shed and used my yaesu ft767 as the receiver ( the only hf set i had that would receive right down to the 50hz mains hum ).
the idea of 73khz fascinated me from the day i saw a pic of a ham with a coil wrapped on a 60 gallon plastic drum with wooden spacing lats and hundreds of feet of longwire antenna complaining that his antenna was so small its efficiency was extremely low,
his dream was to have several thousand meters of wire strung out over the fields behind his house.
