Category Archives: HAM radio transceiver

HF Power-Amplifier MRF101

Post Image

This blog video discusses the power amp design of the DIY transceiver. A single MRF101 LDMOS RF power Mosfet delivers up to 80W in the 20m, 40m and 80m band.

Preamplifier design and test

You can not drive the power amplifier (MFR101A ) directly with the output of the AD831 mixer. 10dBm power ist not enough. So I did design a 14dB voltage gain amplifier to get the needed power to fully get the final 50W output from the power amp.

RF mixers

This video discusses theory, active and passive mixers, simulation with LTSpice and GNU radio. Watch the video here:

Design bandpass and lowpass filter

This is how I did design the bandpass and lowpass filters.

Design a crystal ladder filter

See how I approached the design of a 8 pole crystal ladder filter for SSB @9MHz and with a bandwidth of 2.4 kHz.

Design of the antenna amplifier

Check out how the antenna amplifier got designed, simulated and tested.

Types of Radio Receivers

I did choose to build a super-heterodyne type of receiver. What alternatives do we have?

Introduction Video

Hi all here you find a introduction of the DIY HAM radio transceiver.

DIY HAM radio transceiver

Hi all, I did build my first ham radio transceiver and I thought I let you know how I did it. This might give you ideas about your own HF experiments and give me some feedback from you guys and ideas for new projects. introduction, Types of radio receiver antenna amplifier bandpass and lowpass-filter design […]