It used to be a major rite of passage for a hardware hacker to acquire an oscilloscope. Until recently, new instruments were rarely in normal people’s budgets, so you probably made do with a used scope. Now, there are lots of inexpensive options, especially if you include low-end PC scopes and “scope meters.” Digital meters are also now inexpensive (often free at some major stores), along with signal generators, frequency counters, and even logic analyzers.
But there is one piece of test equipment you don’t see as often as you used to and its a shame, because it is a very versatile piece of kit. Admittedly, if you aren’t doing wireless work, it might not be high on your wish list, but if you do anything with RF, it is not only a versatile tool, but a good value, too. What’s it called? That depends. Historically, they went by the name “Grid Dip Oscillator” or GDO. Sometimes you’d hear it called a “Grid Dip Meter” instead. However, modern versions don’t have tubes (and, thus, no grid) so sometimes you hear them now called dip meters or maybe just dippers.
The controller was a mashup of the existing oven’s keypad and an add-on LCD display (see right). One thing we didn’t see was a schematic. Of course, you can read the code and figure out how it is all connected and (unless you use the exact same oven) you are probably going to need to modify things to suit your particular setup, anyway.
The tablet is based upon an off-the-shelf embedded PC motherboard and touchscreen controller. [Dave] took some offense at the hacked up USB connector on the touchscreen. We have to disagree with [Dave] a bit here, as the video seems to show that a standard mini-b connector wouldn’t have fit inside the tablet’s case. There’s no excuse for the USB cable shield draped over the bare touch controller board though. Things go downhill from there. The tablet’s power supply is best described as a bizarre mess. Rather than use a premade DC to DC converter, whoever built this spun their own switch mode power supply on a home etched board. The etching job looks good, but everything else, including the solder job, is beyond terrible. All the jumps and oddly placed components make it look like a random board from the junk bin was used to build this supply.
