Mare published a new build: This is complete project for 1×6 antenna switch. It was bult in more than 50 pieces around the world and performs really good. Even big guns use it for their systems. The project was designed with help from other OMs (S55O, S59MA, S50LD, S51CT, S51ZJ, SM2WMV/SJ2W and others). More details […]
Tag Archives: HF
Adjustable gain LNA
Mare published a new build: Low noise amplifiers are very useful. I built one with single BFG425W transistor with adjustable bias current. Project info at Mare & Gal Electronics homepage.
Mini CW Keyer / QRSS beacon v1.1
Marko Pavlin has designed a PCB for the CW keyer, he writes: I designed dedicated PCB for the CW keyer. The project is very similar to the version made on prototyping board. Here are the updates: – I added relay and optocoupler for PTT control – The “CW melody” selection pins have three jumpers for 8 […]
Programmable CW Morse Keyer / beacon
Marko Pavlin has designed a Mini USB dongle with STM32F0xx , he writes: Mini USB dongle with STM32F0xx is suitable many for simple, mini projects. I attached speaker to Timer14 PWM output (Pin PA6) and LED (or optocoupler connected to PTT) to GPIO pin PA0 The provided software is based on USB Virtual Com Port (VCP) device. […]
Simple small QRO for HF
Marko Pavlin has been working on a HF amplifier project: I followed the ARRL Homberw challenge 50 watt aplifier entry. It is low cost, simple HF linear amplifier designed and built by the author as an entry in the ARRL’s 2009 Homebrew Challenge contest. The requirements of the amplifier were: 40 meter band 50 watt output […]