I review the Sinometer VC2000 Frequency Counter. You can buy one on Amazon for less than a hundred bucks.
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RGB Rotary Encoder on a Raspberry Pi
The video in this blog entry shows how to connect a rotary encoder to the Raspberry Pi. The particular encoder is from SparkFun and contains a pushbutton switch as well as a tri-color LED.
Read MorePolaroid 312 LED Camera Light – Teardown and Repair
People may have noticed my Camera Light shut down unexpectedly during the Pilotuner video. I finally got around to tearing the camera light apart and fixing it.
Read MoreDIY Variable AC Power Supply
I build a 0-30V adjustable AC power supply for the bench using a Variac, 28 VAC transformer, a digital panel meter, and a handful of other support components.
Read MorePilotuner T601 FM Tube Tuner Restoration
I restore a Pilotuner T601 FM tuner. This is an interesting piece of history, as it’s one of the earliest FM tuners. It doesn’t even have an amplifier and is designed to be attached to an existing radio or receiver.
Read MoreHantek T3100 scope probes unboxing and review
I evaluate some Hantek T3100 oscilloscope probes. These are x100 probes, that I bought for using on high-voltage projects, such as tube radios.
Read MoreEbay VCO module evaluation
I ordered some cheap VCO modules from eBay. Only $20, using an MC1648 VCO oscillator chip, and they work from 70Mhz to 200Mhz.
Read MoreLM2576 constant voltage / constant current switching power supply
I design an adjustable voltage / adjustable current limit power supply using an LM2576 buck converter. For the current limit function, I use an op-amp to measure the current from a sense resistor, a second op-amp to compare that to a pot, and then feed that signal back into the feedback pin.
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