Your First Crystal Radio (How to) or building a crystal radio out of household items. The most difficult part of building a crystal radio is building an efficient earphone that can convert the tiny electrical signals into tiny sounds that our ears can hear. Our first radio used a telephone handset for an earphone, and…
One of my favorite ham radio activities is making contacts on satellites. It’s really fun to know that you’re controlling something that’s receiving and sending communications from space. But communicating with satellites means carrying a big Yagi antenna around. So, I decided to use my fashion sewing skills to make a collapsible fabric Yagi antenna…
Most folks think about the earth’s magnetism only when they need to find their way in the wilderness. When we look at a compass, the earth’s magnetic field appears to be a steady guide. But in reality the magnetic field is anything but stable. Ephemeral undulations, called micro-pulsations, ripple about the ionosphere and generate magnetic…
Construction of the weekend Author: PA0FRI Tube: Russian (Svetlana’s GU-43b) RF Power: About 1.5 KWt
This double-sideband (DSB) radiotelephone transmitter is powered entirely by the instantaneous (not stored) energy produced in the operator’s voice. The RF output power in my prototype falls within the range of 5 to 15mW. The circuit is essentially a high-level DSB modulator/crystal-controlled RF oscillator. DX QSO made by author: 10/13/09 W1VZR 57/459 Limerick, ME …