Our monthly group brings in interesting finds from online. Here's a few r ecent ones still on sale.
Cheap 90V 2HP DC PM motor $39. Not $300!! Finally get around to putting v ariable speed on your drillpress or small lathe. Coilwinding, circle cutti ng, or entry-level wind turbine. (drive it with an old Dart 125-type speed ctrl module, perhaps a footpedal pot.)
At last I can stock up on NE-2s again. My giant bag was depleted.
Giant toroid cheap. Make a tiny science-fair Tesla induction motor? Power chokes for kilowatt triac dimmers, diy classroom transformers and crackpot vector-potential experiments. #26 powder iron code yellow/white, 1.4mH, ha lf a KG. $3.50
The $1.00/g price for liquid Gallium plummeted! Six bucks for a 30g vial! DOH, it immediately went back up to $15. Ah, back down to $7 again. The g allium-sellers all suddenly vanished off eBay? It's on Amazon. Make liquid metal sliding contacts, Faraday HPG motor or kilo-amp dynamos, submarine M HD engines. Meters-wide spun-epoxy solar furnace or Newtonian scope? A bi g mess, stains skin and clothing. Squeeze it together with a chilled indiu m ingot to self-mix some eutectic room-temp liquid alloy.
Cheap wideband power-RF: 1, 7, 20 watt linear amps for 0-200MHz, 144, 1290 MHz, 23cm ham band. These are Motorola cable-tv network amplifier modules, on eBay as MHW612, MHW607-1, CA2830C, CA2818C, CA5800C, MHW1815, MHW1915
-mhw1815-1915-mods-23cm
Silver ink for half price. Should be $30/8g, not $15/8g (two pens.) To ac cess the ink, backwards-unscrew the blue pen body, pry out the white plasti c/spring assy. Shake well first (steel shaker-balls inside.) Ink dilutes with xylene. Use for attaching leads to platinum surfaces or PZT transduce rs or ITO electrodes, pcb repairs, add shielding to pcb, draw antennas or e lectrodes on plastic and glass, etc. Broken car-window heaters live once m ore. Hidden conductors along the edges of your Daedalus Dreadco fake perpe tual motion machines.
$8 Strobe-droplets fluid pump at Goldmine. Usually the famous "strobe fou ntain" device with backwards-falling water droplets employs a Goreman-Rupp oscillating chemical-pump for $150 each. Produces 60Hz falling droplets. These pumps below are $8 (or, sometimes on sale.) But they're 230VAC, not
120VAC. They stop working if below 140VAC or so. Also, the internal part s on some are stuck, so disassemble and free up the spring-valve and moving core (don't lose the tiny spring!)"Desert Glass" is all the rage. Ancient impactor: a light so bright that a portion of the Sahara desert melted inches deep and flowed downhill. It's greenish like non-radioactive Trinitite fragments, King Tut's breastplate scarab. "Libyan obsidian," used for ancient knapped tools. Tiny hunks on eBay for about five bucks. Now waiting for someone to fake it with electri c furnace and Libyan sand, sell some for $500/KG.
Thermal camera experiments, germanium lenses way too expensive. Try ZnSe le nses, amazingly cheap from the CO2 laser industry. They don't block sunlig ht; just add a piece of vis-opaque silicon wafer.
Attain a DC megavolt? Microwave oven rectifiers now at $0.20 cents! Perha ps a volt-multiplier ladder, 20KV per stage, inside an oil-filled pipe. Als o find 100nS fast rectifiers, if you want 100KHz high-watts drive instead o f feeble 60Hz. HVM-12 12KV 350mA
To go with voltage multipler, here's a source of large N. Tesla posters (It aly)
But the giant 6ft cardboard Nikola Tesla is out of stock! Darn.
(((((((((((((((( ( ( ( ( (O) ) ) ) ) )))))))))))))))) William J. Beaty