This presentation is about “hardware defined” radios. Although I think that SDRs (i. e. Software defined radios) 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 highly innovative designs on the market like building a relatively cheap amateur radio transceiver by using an 8-bit microcontroller as part of the radio frequency circuits, In my opinion a “real” radio must have filters, mixers, low-level amplifiers and other “old style” stuff. So let me invite you on a trip back to the 1970s and 80s, when engineering a radio was more about the knowledge of circuits than about computers.
Should you have any questions or comments please mail
peter(at)dk7ih.de !
Latest entries:
25 Watts 8 Band SSB Transceiver for outdoor operation (SOTA/POTA etc.)
(April 2026)
50 Watts and 5 Bands SSB mobile transceiver for short wave
(September 2025)
The “SCR”-Transceiver – A Simple and Compact Radio
(March 2025)
An updated handheld SSB transceiver for 14MHz
(April 2024)
Older Articles
Transceivers/Two-way radios for SSB modulation
With analog VFO
With digital VFO
Multiband
-
-
-
- “Gimme Five” reloaded – A compact 5 band QRP SSB transceiver for 1.8, 3.5. 7, 14 and 18MHz
- An experimental HF 6-band SSB transceiver for 1.8, 3.5, 7, 14, 21, 28 MHz
- QRP SSB multiband transceiver (5 bands/10 Watts PEP) for 3.5, 7, 14, 21 and 28 MHz
- A 10-band shortwave radio with 10+ watts of output (Sep 2023)
-
-
Monoband
Handheld/”Walkie-Talkie”
Station transceivers
-
-
-
- High performance transceiver for voice communication on 14MHz
- The “Cigarette Pack” Transceiver (14MHz, SSB, 4Watts PEP)
- The “Micro42” – Another “shirt pocket” SSB transceiver.
- The „Micro20 III“ – A Simplified Pocket Size SSB Transceiver for 14 MHz
- My 1st “Shirt-pocket” transceiver (re-engineered)
- An ultra compact QRO transceiver for 40 Meters
-
-
Classical Circuits – A collection of tested and proven modules
-
-
-
- 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)
- Module 7: LC tuned Colpitts VFO for 5 MHz
-
-
Test equipment
Antennas and Tuners
-
-
-
- A semi-automatic antenna tuner for QRP use
- Reviewing and improving the semi-automatic antenna tuner
- The semi-automatic antenna tuner – Version 1b
- Improved matching for 20-meter-band rod antenna
- Mounting a rod antenna to a homemade handheld QRP transceiver
- An easy-to-build rod antenna for 14 MHz (20 meter band)
-
-
Book
Microcontroller related material
-
-
-
- My website on AVR and ARM microcontrollers: micromaker.de
-
-
Digital radio frequency generation (DDS etc.)
Tutorials, Algorithms etc.
-
-
-
- Simple GPS-Decoder (NMEA) with STM32F4 using USART
- Tutorial: Register Programming of the STM32F4/ARM-Cortex-M4 Microcontroller
- Direct FM generation with fast MCU and parallel DDS
- Decoding time station signals (DCF77 etc.) with a microcontroller
- Interfacing colored LCD ILI9341 with 8-bit Microcontroller
- Decoding NMEA data from a GPS module with a microcontroller
- Interfacing an LCD12864 (ST7920 controller) to a microcontroller
- Interfacing an analog temperature sensor to an AVR microcontroller
- Simple GPS-Decoder (NMEA) with STM32F4 using USART
-
-
Scuba diving
Remote controlling, telemetry etc.
My code collection on Github (Embedded C for AVR and STM32)
Misc