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 !

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Latest entries:

• The “SCR”-Transceiver – A Simple and Compact Radio

 

 

 

 

• A trashy radio: Trying to get a BAOFENG BF-17H VHF/UHF working.

 

 

 

• An updated handheld SSB transceiver for 14MHz (2024-04-04)

 

 

 

 

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Older Articles

Transceivers/Two-way radios for SSB modulation

With analog VFO

• • • • A mid-power portable/handheld SSB transceiver for 14MHz
      • Going back in time: “Old school” transceiver for 20 meters with 20 watts of output
      • A “lean design” SSB-Transceiver for 14 MHz 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”

• • • • A “Walkie-Talkie” SSB transceiver for 14MHz or higher rf bands
      • A compact handheld QRP SSB transceiver for 14 MHz

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

• • • • A simple 2-tone-generator for testing the linearity of SSB transmitters
      • A Dual Audio Frequency Generator with 2 DDS modules
      • Cheap and dirty measurement of filter response curves

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

• • • • Das QRP-Baubuch (3rd edition, German language only, 1993)

Microcontroller related material

• • • • My website on AVR and ARM microcontrollers: micromaker.de

Digital radio frequency generation (DDS etc.)

• • • • Programming the AD9834 DDS chip
      • A simple software to control the Si5351A clock generator chip (Version for STM32F4)

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

Scuba diving

• • • • An open source dive Computer (Buhlmann ZH-16 algorithm)

Remote controlling, telemetry etc.

• • • • A 433MHz RC unit for large scale model train locos (RFM12B)
      • Telemetry data transmission from stratosphere to ground control

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

• • • • https://github.com/DK7IH

Misc

• • • • Fake components – and how to recognize them
      • Issues and observations using the Si5351 clock oscillator in the VHF range