Welcome to DK7IH.de!

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Welcome to my website on “Old School” QRP radios!

These sites deal with “hardware defined” radios. Although I think, that SDRs are a great invention, this website is dedicated to the “old school” style of building ham radio transceivers. In spite of the fact that there are some innovative designs on the market like building a relatively cheap amateur radio transceiver by using a microcontroller as part of the radio frequency circuits, I strongly believe that a “real” radio must have filters, mixers, amplifiers and other “old style” stuff.

Should you have any questions, comments or you would like to buy a radio kit, components or other material, please mail

peter(at)dk7ih.de !

Please keep in mind that the designs are free for non-commercial use and for educational purposes. Any commercial exploitation would violate this copyright. Thank you!

Latest entries:

A 10-band shortwave radio with 10+ watts of output (Sep 2023)

DK7IH multiband SSB transceiver for 10 bands and 10 watts PEP output (C) 2023 by Peter Baier (DK7IH)

Issues and observations using the Si5351 clock oscillator in the VHF range

(Mar 11, 2023 )

VFO/LO for a multiband tranceiver project

Universal VFO with an Si5351 clock generator

Universal AD9951 DDS VFO module for QRP projects

“Walkie-Talkie” SSB transceiver for 14MHz or higher rf bands


Classical QRP Circuits – A collection of tested and proven modules for QRP radios

Module 1: SSB generator using MC1496N

Module 2: Transmit Mixer with the MC1496N IC

Module 3: QRP SSB PA with 10 Watts PEP

Module 4: Si5351 VFO module

Module 5: AD9951 VFO module

Module 6: Crystal controlled local oscillator (LO) (NEW!)

Module 7: LC tuned Colpitts VFO for 5 MHz (NEW!)

More Amateur radio equipment

QRP-Transceivers/Two-way radios for SSB modulation

With analog VFO

With digital VFO



Station transceivers

Test equipment

Antennas and Tuners

Literature by Peter (DK7IH)

Microcontroller related material

Digital radio frequency generation (DDS etc.)

Tutorials, Algorithms etc.

Scuba diving

Remote controlling, telemetry etc.

My code collection on Github (Embedded C for AVR and STM32)