Pocket-sized VLF antenna keeps comms open where conventional radios fail
Pocket-sized VLF antenna keeps comms open where conventional radios fail
A high Q piezoelectric resonator as a portable VLF transmitter
A high Q piezoelectric resonator as a portable VLF transmitter
Pocket-sized VLF antenna keeps comms open where conventional radios fail
A high Q piezoelectric resonator as a portable VLF transmitter
A high Q piezoelectric resonator as a portable VLF transmitter