Day: December 16, 2015

Rubber Tanks And Sonic Trucks: The Ghost Army Of World War II

December 16, 2015 by 43 Comments

Winston Churchill once told Joseph Stalin “In wartime, truth is so precious that she should always be attended by a bodyguard of lies”. During World War II, the power of these bodyguards, in the form of military deception, became strikingly apparent. The German military was the most technologically advanced force ever encountered. The Germans were the first to use jet-powered aircraft on the battlefield. They created the enigma machine, which proved to be an extremely difficult system to break. How could the Allies possibly fool them? The answer was a mix of technology and some incredibly talented soldiers.

The men were the 23rd Headquarters Special Troops, better known as the Ghost Army. This unit was the first of its kind specifically created to deceive the enemy. Through multiple operations, they did exactly that. These 1100 soldiers created a diversion that drew German attention and gunfire to them, instead of the thousands of Allied troops they were impersonating.

The Ghost Army consisted of 4 distinct groups:

  • The 406th Engineer Combat Company Special were 166 “regular” soldiers – these men handled security, construction, and demolition.
  • 603rd Camouflage Engineers were the largest group at 379. As the name implies, the 603rd was created to engineer camouflage. 
  • 3132 Signal Service Company consisted of 145 men in charge of half-tracks loaded down with massive 500 watt speakers which could be heard for 15 miles. 
  • The Signal Company Special Formerly the 244th signal company, The 296 men of the Signal Company Special handled spoof radio communications.  The Germans heavily relied on captured and decoded radio messages to determine the Allies’ next move.

Continue reading “Rubber Tanks And Sonic Trucks: The Ghost Army Of World War II” →

TI Releases New Edition Analog Engineer’s Pocket Reference

December 16, 2015 by 25 Comments

We aren’t sure that a PDF with 100 pages in it qualifies as a pocket reference, but TI’s Analog Engineer’s Pocket Reference is certainly a good read. You do have to register with TI (use a disposable address if you are too paranoid to do that), but the free download is well worth the effort. The document’s been around for awhile, but TI recently released a new 4th edition.

The first few pages might underwhelm you. You probably know the standard decimal prefixes and are more likely to ask Google to convert circular mils to square millimeters, for example. The second part, though, gets more into electronics. There’s standard values for resistors and quick reminders about the difference between X7R and Y5V ceramic in capacitors, for example.

Things get progressively more interesting, covering measurements and phase shifts, and then amplifiers. The little circuits are pithy but cover the bases including things like frequency response.

Continue reading “TI Releases New Edition Analog Engineer’s Pocket Reference” →

RC Mini Flame Thrower Brings The Burn

December 16, 2015 by 17 Comments

It goes without saying that a radio controlled mini flame thrower can be nothing but a bad idea and you should never, ever build one. But once you watch the video below, you’ll be tempted to try. But don’t do it – you’ve been warned.

That said, the video below shows that [Make-log]’s remarkably compact build is chock full of safety interlocks and sports a thoughtful and informative user interface. It’s fueled by a small can of spray deodorant whose valve is actuated by a servo and ignited by a spark-gap igniter. Alas, this final critical component is no longer available from SparkFun, so if you choose to roll your own – which you shouldn’t – you’ll need to find a substitute.

We’ve featured an unreasonable number of flame thrower projects before, including a ton of wrist–mounted units. Of course if you’re a musically inclined pyromaniac, you’ll also want to check out this mini Doof Warrior setup too.

Continue reading “RC Mini Flame Thrower Brings The Burn” →