Leader RedBaird Posted October 4, 2021 Leader Posted October 4, 2021 11 hours ago, Wolf said: Dude laughing my ass off That made mentally picture a very strange police BOLO: "Be On the Look Out for" Quote
Leader RedBaird Posted October 4, 2021 Leader Posted October 4, 2021 20 hours ago, DJ aka GDR DJ said: The British built very large parabolic audio reflectors/amplifiers out of concrete in WW2. ACK! I was wrong! They had them in WW ONE, listening for the sound of Zeppelins! The pic below is a collection of them from the World Wars, In ww2, they had a method of using two or more of such 'listening ears' to get more accurate distance-estimations. That helped with the much faster aircraft. Part of that Dutch device looks like it came from a medical stethoscope. Quote
ajnl Posted October 4, 2021 Posted October 4, 2021 1 hour ago, RedBaird said: Part of that Dutch device looks like it came from a medical stethoscope. I read that you could pump those sides up with the 'stethoscope' looking thing so that the 'ears' can fit multiple people. 1 Quote
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