Hard to build wide frequency range SDR kit

I have made many experiments with my DVB-T SDR stick. It can handle frequency range from around 30 MHz up to more than 1 GHz. There are cases, where there is need to receive lower frequencies. To make receiving those low frequencies with such cheap RTL-SDR receiving sticks, there are two approaches: using upconverter or

BG7TBL RF noise source

I have played with software defined radio using cheap DVB-T stick for some time. Receiving radio transmissions is interesting, but it works also for other applications. By reading RTL-SDR Tutorial: Measuring filter characteristics and antenna VSWR with an RTL-SDR and noise source article I understood that I could use my RTL-SDR stick for many RF

DC-4.0GHz RF Fixed Attenuator

RF attenuators are a universal building block within the RF design arena. I neeeded some RF attenuators for my electronics lab. I found this cheap product  DC-4.0GHz RF Fixed Attenuator from Banggood. They seemed to have pretty good specfications and features considering that the price is just slightly over 7 Euros for three attenuators: Frequency

Arduino Sensor Kit 37 In 1

Arduno neeeds sensors.  Geekcreit® 37 In 1 Sensor Module Board Set Kit For Arduino Plastic Bag Package  promises to give many sensors cheaply. That kit says that t contains 37 sensors. Actually it has 37 items, but not all of them are sensors (there are buzzer, relay, LED etc.). It is cheapest kit on the

Tiny Tesla coil tested

Tesla coils and other high voltage equipment that make sparks are always entertaining and potentially dangerous. There are  some portable tesla coils you can buy online that say, “safe, low current”, and yet they still produce lightning and have a high voltage output.700K Mini Coil Tube Neon Glow Coil With Transparent Plate Power Supply For

Small switch mode PSU module MPS MP2307 fail

I  need power supplies for different eletronics circuits. I decided to get some cheap switch mode power supply modules 5Pcs Mini DC Adjustable Power Supply Buck Module Step Down Module (available also as single unit). The ideas was to try to use them instead of power wasting traditional linear regulators. 5Pcs Mini DC Adjustable Power

HB100 microwave radar to Arduino

A Doppler radar is a specialized radar that uses the Doppler effect to produce velocity data about objects at a distance. It does this by bouncing a microwave signal off a desired target and analyzing how the object’s motion has altered the frequency of the returned signal. Doppler radar technology used to be expensive, but

Fiber optics power meter

An optical power meter (OPM) is a device used to measure the power in an optical signal. The term usually refers to a device for testing average power in fiber optic systems. Power meters are part of the toolbox essentials for all technicians installing or maintaining any type of fiber networks. They are used to

DMX-512 decoder for RGB LED

I have earlier written on using DMX-512 controlled dimmer to control mains powered lamps. It works, but is expensive and traditional incandescent lamps are going out of fashion. LEDs are the future, so a cheap easy to use board for controlling low voltage LEDs with DMX-512 signal are needed. To experiment with LED conrolling I