Since I fitted my scope with a SMPS based 12v input supply, there has been a noise problem on very low volts/div settings, this noise isn’t present on the mains supply, so I can only think it’s coming from the switching frequencies of the various DC-DC modules I’ve used. Because
Continue readingRigol DS1054Z 12v Power Supply Noise Filtering
In my shack, 99% of my gear is all 12v powered, which is good for a few reasons: Single Power Supply – This increases efficiency, as I’m only getting the losses of a single supply. Safety – Mains voltages are dangerous, I’m not fond of working on such equipment. Portability
I recently posted about a small analog SWR/Power meter I got from eBay, and figured it needed some improvement. After some web searching I located a project by ON7EQ, an Arduino sketch to read SWR & RF power from any SWR bridge. The Arduino code is on the original author’s
After watching a video over at Scullcom Hobby Electronics on YouTube, I figured I’d build one of these precision references to calibrate my multimeters. It’s based around a REF102P 10v precision reference & an INA105P precision unity gain differential amplifier. For full information, check out the video, I won’t go
Here’s another active balancing circuit for large ultracapacitor banks, this one is designed for a series string of 6, at 2.5v per capacitor. Based on the design here, I have transcribed the circuit into Eagle & designed a PCB layout. As can be seen from the circuit diagram above, this
I’ve been doing some tinkering with the RN-52 Bluetooth Audio module from Roving Networks, in prep for building a portable wireless speaker system, & thought I’d share my designs. Initially I was having some issues with RF noise on the audio output from the RN-52, as I was only using