I've not seen any love here at the site for crystal radio sets. Before you roll your eyes, crystal radios were THE only radio most folks had, and were considered good enough for both the Navy and Army - for WWI. Many use no power, offer fantastic selectivity and sensitivity (compared to some of the cheap Chinese crank 'sw' radios). Some radio kits offer audio amplifiers vice RF amps. The same applies, more technical kits offer both RF and audio amplifiers. NONE have so-called local-oscillators (LO). A LO emits measurable RF energy and can be detected and DF'd. For the truly paranoid, crystal sets offer an opportunity to have a sophisticated receiver - covering AM and short wave that is 'dead' -- something that emits no energy. On the other hand, you can build a crystal set - yourself -from junk or from a kit, learn a bit about tuned circuits and radio in the process. So? So, here are some links that offer both finished radios, and kits that go from simple to wild. Couple of years back when my son was in the Cubs, we took a den out out the desert and gather all the needed materials for a radio (except headphones) from wire & diode (busted TV) wooden base (orange crate) coil forms (PVC pipe). Each made a working radio in two sessions. SO - if you have kids, grand kids or just want to have fun, check out these inks. Kits THE DUNWOODY HIGH PERFORMANCE CRYSTAL RADIO KIT!! (AM thru 12 Mhz) Borden Radio Company - Radio Kits and Designs for Old and New Styles For the DIY type with some background https://antiqueradio.org/econoceanic.htm (DIY radio) From junk The Creative Science Centre - by Dr Jonathan P. Hare Examples of what can be done with a bit of time and care Dave's Homemade Crystal Radios Main Page. Ready made radios Shortwave Crystal Radio Receiver Kits can run from 8 to 10 USD all the way to 100S of USD. IF you are looking to combine your woodworking,metal, and radio skils, this is one way to have fun. SO or You get to chose. Have fun.
The bottom one is the one I built as a cub scout. Used it for years, long wire antenna from the house to the garage, about 100 feet, grounded to the radiator. (I don't see the whisker, tho', must be a diode.)
There was an old Ham when I was young that a room full of the wound Crystals for all kinds of wave lengths . I wish I had paid more attention to what he was trying to tell me .Opportunities lost !!!!!
In 1960 I spent a year in the hospital, and the only radio I was able to get was a red plastic rocket shaped one that only had a ground wire ( alligator clip) and an earphone. Last I saw one was on ebay for well over $100.!
I got my start with a crystal set At 8 I built a crystal set from a Cub Scout kit (major dollars if you can find them today), then a 3 transistor regen, fixed old radios in high school. Joined the service, got a commercial phone, then later, an extra class ticket. Made my living for 20+ years working with radios. LOtta fun. Today, it's all digital, and card swapping. Good radios, no real need for a tech - a card swapper will keep them running. Better radios, less 'fun'. Crystal sets are just fun.
I can't believe $24 or $26 for variable capacitors! I haven't thought of those in years; thank you for the post DKR.
I It built my first crystal set in 1958 and I clearly remember how shocked I was when it worked. All I remember is that is had a multi-tap hand wound coil. It was so much fun! Great memories. Thanks for the good post!
My daughter and I built one about 5 years back. It was great fun for a school science fair. We used the diode instead of the old "cat's whisker" like I had when I was a boy scout. It was really cool to see her eyes light up when it worked with NO BATTERIES!
I've updated the links on the OP and posted this as a PING rather than start a new thread. Winter, with long cold nights, is a good time to build an old timey crystal set and have some fun. No batteries included as they are not needed!
I had other electricians at work call me a liar when I said I could build a radio that didn't need power. They were awful young.
Sould have made them a Bet, Say a hundred Bucks.... Just enough to hurt their pocket book at the tavern...
My big brother built a crystal set and we enjoyed it listening to it and knowing nothing about why it worked. Magic
Great post & links. My first radio was a x-tal set, have built many over the years, and still have my favorite one set aside as a backup. You will discover that some layouts work better than others, and coil winding is a science unto itself. Those expensive and no longer salvageable big metal plate variable capacitors can be substituted with newer plastic ones out of old boom boxes or pocket radios, or aluminum foil separated by wax paper. High impedence earphones, also on the endangered list, can be replaced with crystal ear pieces available now, put some back as they are cheap and hard to build. Salvaged copper wire from transformers wound on varnished dry toilet roll tubes work pretty well for the inductor coils, and provide wire for antennas, circuits, and grounds. Lots of ways to go, educational, fun, and could be an essential piece of gear, along with the skill to build one from scratch.