Schematic of the 4 tube radio, experimentally built in a way of the radio-pioneers (1910-1945). The radio acts as a cascade type receiver when the antenna coil has a high self-inductance, with lower self-inductances of the antenna coil you can put in a mixing process with the oscillator. Perhaps...

Experimental receiver for VLF. I received electromagnetic (radio) signals between 14 and 22 KHz with a capacitor of 4,7 NF over the showed coil. The schematic is identical to that of the storm detector IV (with the 6088 Tube), the coil is differently constructed. There is one more transistor...

The X-Band microwave motion detector was moved to 10.25GHz. We explore the output of the HP x421A detector diode attached to the HP x532A X-Band wavemeter, and verify the frequency of operation.

Observations of electromagnetic (radio) signals on very low frequencies, 0 KHz - 10 KHz. Observed 10 may 2008, approx. 23.00 hour on 4,5. KHz: next to the original radio resonance of 4,5 KHz there is another resonance (spectrum on approx. 10 KHz), that comes in and fades away after 30 minutes....

Since 1923, NIST radio station WWV has provided round-the-clock shortwave broadcasts of time and frequency signals. WWV\'s audio signal is also offered by telephone: dial (303) 499-7111 (not toll-free). A sister station, WWVH, was established in 1948 in Hawaii, and its signal can be heard by...

A tour of the home built AM transmitter racks 771fd6292de1efd4.flv 771fd6292de1efd4.flv 771fd6292de1efd4.mp4 4b767bdd2c8d1.jpg