Yes, Mailbag Monday is back! Weekly mailbag videos to come. Perhaps the worst schematic ever seen? SPOILERS: Only two items for today’s Mailbag, and I had a lot to say on each. The WIHA SpeedE Electric Screwdriver 16:10 Will the HaasoScope 4CH 60MHz 200MS/s change Dave’s mind on USB oscilloscopes: https://www.crowdsupply.com/andy-haas/haasoscope https://github.com/drandyhaas/Haasoscope/ Forum HERE

What’s is this obscure 1970’s bit of kit from a big name manufacturer? AliExpress Affiliate Forum HERE

This sub US$500 Eakins microscope from Aliexpress seems identical to the new AU$1800 Suba Engineering microscope for 1/3 the cost. And Dave shows how it can out perform the $4500 Tagarno! http://s.click.aliexpress.com/e/b7ycSav2 http://s.click.aliexpress.com/e/eN3Ec5a http://s.click.aliexpress.com/e/bHSXalzm http://s.click.aliexpress.com/e/cMimkzYc Forum HERE

Inside the new Rigol 7000 Series oscilloscope with custom ASIC’s. Also a look at the bootloader code for potential hacks. Forum HERE Hi-res photos:

The new official Power Over Ethernet (PoE) hat for the Raspberry Pi 3 B+ has been reported to fail with an overcurrent error when powering USB devices. Dave investigates and narrows it down until, well, something goes horribly wrong… Rpi forum Forum HERE

Who saw it coming?, Fontus have filed for bankruptcy! The infamous “self-filling water bottle” that raised $340k on Indiegogo has gone bankrupt and delivered nothing. You ‘canna beat the laws of physics Captain! https://www.ksv.at/insolvenzfaelle/insolvenz-fontus-water-technology-gmbh-1030-wien http://www.fontus.at/fontus-update.pdf https://www.indiegogo.com/projects/fontus-the-self-filling-water-bottles#/ Forum HERE

Gav “The Mechatronics Guy” explains circular polarised light and demonstrates his physical laser cut models to help understand this concept in his quest to make a pixel mapped polarised light camera. How do 3D shutter glasses work? https://tinkerings.org/

Bart Schroder from Cleverscope talks about the challenges in designing the world’s highest performance isolated oscilloscope. Measurement demo on a 500V MOSFET H-Bridge and how to accurately probe it. Then a teardown and walk through of the design of the new CS448 1kV 4CH 200MHz 14bit isolated oscilloscope and the custom probes, power supplies and ...

Why do many powered studio monitor speakers have a low level audible background noise? This is an issue with many big and popular brand monitors like KRK, Yamaha, JBL, Alesis and many others Time for some investigation on the KRK Rokit 6 studio monitor speakers to track down where the noise is coming from. NOTE: ...

Are power planes in a 4 layer PCB any good as a capacitor? Can it work as one big bypass capacitor? A look at an discussion on PCB layer stackups, and some measurements on 4 and 8 layer PCB power planes with different prepreg thicknesses and how well they work as a capacitor. https://www.xilinx.com/support/documentation/application_notes/xapp623.pdf https://www.researchgate.net/publication/242415439_High_Performance_FPGA_Bypass_Networks ...