Uploaded April 2025 | Updated September 2026, 1 week ago
Only $5 for 10 PCBs and every new member get $5 bonus. + Express 24 hour / 48 hour service on pcbway.com ➠ ➠ ➠ After building the first version of this DIY AM transmitter (which you may have seen in a previous video, linked below), I knew I could do better. That build worked well enough, but I wasn’t fully satisfied with the performance or flexibility — especially when it came to tuning and modulation.
This updated version is a huge step forward. It still uses Charles Wenzel’s excellent low-power AM transmitter circuit as its core, but I’ve added several enhancements that make it far more practical and enjoyable to use:
- Bluetooth audio input, so you can stream music wirelessly from your phone or computer;
- Adjustable transmit frequency, ideal for avoiding interference on the MW band;
- Adjustable modulation depth to fine-tune sound quality and prevent distortion;
- Antenna tuning, allowing you to match a short wire antenna for best range;
- 3-meter wire antenna, chosen to comply with legal low-power transmission limits.
The result is a compact AM transmitter with surprisingly good audio and enough range to fill the house — even with a simple wire antenna and battery power. It’s the perfect companion for vintage radios, audio testing, and a touch of retro broadcasting fun.
I’m now much happier with the design, and as promised, I have made the PCB available on PCBWay for anyone who wants to build one. I have also added a link to a Google Drive Folder that has the Schematic and the 3D print files for the enclosure that I used in the video. Links below.
Enjoy the build, but … CHECK THE LEGAL REQUIREMENTS AND LIMITS IN YOUR COUNTRY. IN MANY COUNTRIES YOU ARE NOT PERMITTED TO TRANSMIT ANYTHING ON AM WITHOUT A RADIO OPERATOR LICENSE.
🎥 First version video:
youtu.be/m06D2XC9nwQ
🔗 PCBWay Shared project:
pcbway.com/project/shareproject/Low_Power_AM_Transmitter_with_Bluetooth_9476bba8.html
🔗 Google Drive Folder:
drive.google.com/drive/folders/1PZ2bq2ye7zLTtz9gByvMRhFt14ShbGX9?usp=sharing
🔗 Charles Wenzel’s original project: techlib.com/electronics/amxmit.htm
🔗 Variable oscillator inspiration: geojohn.org/Radios/MyRadios/AMXmitr/AMXmtr.html
🙏 Want to support the channel? ●●●●●●
patreon.com/mcaldeira
paypal.me/macaldeira
#AMTransmitter #BluetoothToAM #VintageRadio
______HUNDREDS OF OTHER VIDEOS TO CHOOSE FROM_____
DIY TEST GEAR: The title says it all:
youtube.com/watch?v=7buNHf6HoDw&list=PLy5M_tA9ux7KkjmWX0I0zNocg6NF33EfL
RESTORATION BUILDING BLOCKS: A series of videos showing detailed steps used the restoration process of tube equipment:
youtube.com/watch?v=7xvTGd4ysRE&list=PLy5M_tA9ux7JSYx8z2mw303vx287LHpzf
HowTo's: Various videos on some simple techniques and projects:
youtube.com/watch?v=lgr-J_D6pSU&list=PLy5M_tA9ux7K3B77iUGyLPai3RIvJOrkO
See also playlists on some other completed restoration projects.
PHILIPS BX750A:
youtube.com/watch?v=i8U9Lteja5o&list=PLy5M_tA9ux7IG6XgctidGO0u0DeT3_CxF
TELEFUNKEN OPUS 2114:
youtube.com/watch?v=_HO2bjY5vuw&list=PLy5M_tA9ux7LhcZ9h9plfTFmjaM1mcifu
SABA UW-175-Z 3D:
youtube.com/watch?v=cca4i60ZLw4&list=PLy5M_tA9ux7IWL18nsrSf4RnjsuPjHC-p
GRUNDIG 1070:
youtube.com/watch?v=i4J5l0fwhko&list=PLy5M_tA9ux7JgnyYPRWOK763aJ8bg3iCI
SCHAUB-LORENZ GOLDY 58 type 3020:
youtube.com/watch?v=RSbt7qVed78&list=PLy5M_tA9ux7IBse5G--Kl89SPS9sATXfZ
BUSH VHF64:
youtube.com/watch?v=U--6JymkQ1M&list=PLy5M_tA9ux7KsvN5M48cX6cxN4jSz0s3X
GRUNDIG 3060A:
youtube.com/watch?v=7x2sK2GSYeE&list=PLy5M_tA9ux7L8e9h8lrHGREPqcgWO-YQm
TELEFUNKEN OPERETTE 8:
youtube.com/watch?v=5IsACM0mPzs&list=PLy5M_tA9ux7K3SXDv8Hu4uAyl1O7NE5dc
GRAETZ SUPER 171W:
youtube.com/watch?v=MhG-CH0gqm4&list=PLy5M_tA9ux7IjUykGE8neJSI6GUxMl2YG
LOEWE-OPTA MAGNET 3737W:
youtube.com/watch?v=ZSZBJ5sKQm8&list=PLy5M_tA9ux7J_hzDhnF8rs2c7wmgGfRlK
BRAUN ATELIER 3:
youtube.com/playlist?list=PLy5M_tA9ux7L3k5nPRvrk1aH764QRCTqE
LOEWE-OPTA TRUXA STEREO 4741W:
youtube.com/playlist?list=PLy5M_tA9ux7KhVk0KqPx0Wkh2KO_5f2fQ
GRAETZ COMEDIA 616:
youtube.com/watch?v=fwmW9k3TwNE&list=PLy5M_tA9ux7L5sAApLzV6xoYzmRNJpMW5
SABA FREIBURG W2:
youtube.com/playlist?list=PLy5M_tA9ux7IqvS-LshUGpE1D_WY6mrZe
GRAETZ MUSICA 4R417:
youtube.com/playlist?list=PLy5M_tA9ux7Ios98E59dWjwc2SRJyxwIn
You may also be interested in ...
CAPACITOR LEAKAGE TESTER:
youtube.com/watch?v=0pySErvzUIY&list=PLy5M_tA9ux7KWexvEjLB0SANSxQXi0zTS
Only $5 for 10 PCBs and every new member get $5 bonus. + Express 24 hour / 48 hour service on pcbway.com ➠ ➠ ➠ After building the first version of this DIY AM transmitter (which you may have seen in a previous video, linked below), I knew I could do better. That build worked well enough, but I wasn’t fully satisfied with the performance or flexibility — especially when it came to tuning and modulation.
This updated version is a huge step forward. It still uses Charles Wenzel’s excellent low-power AM transmitter circuit as its core, but I’ve added several enhancements that make it far more practical and enjoyable to use:
- Bluetooth audio input, so you can stream music wirelessly from your phone or computer;
- Adjustable transmit frequency, ideal for avoiding interference on the MW band;
- Adjustable modulation depth to fine-tune sound quality and prevent distortion;
- Antenna tuning, allowing you to match a short wire antenna for best range;
- 3-meter wire antenna, chosen to comply with legal low-power transmission limits.
The result is a compact AM transmitter with surprisingly good audio and enough range to fill the house — even with a simple wire antenna and battery power. It’s the perfect companion for vintage radios, audio testing, and a touch of retro broadcasting fun.
I’m now much happier with the design, and as promised, I have made the PCB available on PCBWay for anyone who wants to build one. I have also added a link to a Google Drive Folder that has the Schematic and the 3D print files for the enclosure that I used in the video. Links below.
Enjoy the build, but … CHECK THE LEGAL REQUIREMENTS AND LIMITS IN YOUR COUNTRY. IN MANY COUNTRIES YOU ARE NOT PERMITTED TO TRANSMIT ANYTHING ON AM WITHOUT A RADIO OPERATOR LICENSE.
🎥 First version video:
youtu.be/m06D2XC9nwQ
🔗 PCBWay Shared project:
pcbway.com/project/shareproject/Low_Power_AM_Transmitter_with_Bluetooth_9476bba8.html
🔗 Google Drive Folder:
drive.google.com/drive/folders/1PZ2bq2ye7zLTtz9gByvMRhFt14ShbGX9?usp=sharing
🔗 Charles Wenzel’s original project: techlib.com/electronics/amxmit.htm
🔗 Variable oscillator inspiration: geojohn.org/Radios/MyRadios/AMXmitr/AMXmtr.html
🙏 Want to support the channel? ●●●●●●
patreon.com/mcaldeira
paypal.me/macaldeira
#AMTransmitter #BluetoothToAM #VintageRadio
______HUNDREDS OF OTHER VIDEOS TO CHOOSE FROM_____
DIY TEST GEAR: The title says it all:
youtube.com/watch?v=7buNHf6HoDw&list=PLy5M_tA9ux7KkjmWX0I0zNocg6NF33EfL
RESTORATION BUILDING BLOCKS: A series of videos showing detailed steps used the restoration process of tube equipment:
youtube.com/watch?v=7xvTGd4ysRE&list=PLy5M_tA9ux7JSYx8z2mw303vx287LHpzf
HowTo's: Various videos on some simple techniques and projects:
youtube.com/watch?v=lgr-J_D6pSU&list=PLy5M_tA9ux7K3B77iUGyLPai3RIvJOrkO
See also playlists on some other completed restoration projects.
PHILIPS BX750A:
youtube.com/watch?v=i8U9Lteja5o&list=PLy5M_tA9ux7IG6XgctidGO0u0DeT3_CxF
TELEFUNKEN OPUS 2114:
youtube.com/watch?v=_HO2bjY5vuw&list=PLy5M_tA9ux7LhcZ9h9plfTFmjaM1mcifu
SABA UW-175-Z 3D:
youtube.com/watch?v=cca4i60ZLw4&list=PLy5M_tA9ux7IWL18nsrSf4RnjsuPjHC-p
GRUNDIG 1070:
youtube.com/watch?v=i4J5l0fwhko&list=PLy5M_tA9ux7JgnyYPRWOK763aJ8bg3iCI
SCHAUB-LORENZ GOLDY 58 type 3020:
youtube.com/watch?v=RSbt7qVed78&list=PLy5M_tA9ux7IBse5G--Kl89SPS9sATXfZ
BUSH VHF64:
youtube.com/watch?v=U--6JymkQ1M&list=PLy5M_tA9ux7KsvN5M48cX6cxN4jSz0s3X
GRUNDIG 3060A:
youtube.com/watch?v=7x2sK2GSYeE&list=PLy5M_tA9ux7L8e9h8lrHGREPqcgWO-YQm
TELEFUNKEN OPERETTE 8:
youtube.com/watch?v=5IsACM0mPzs&list=PLy5M_tA9ux7K3SXDv8Hu4uAyl1O7NE5dc
GRAETZ SUPER 171W:
youtube.com/watch?v=MhG-CH0gqm4&list=PLy5M_tA9ux7IjUykGE8neJSI6GUxMl2YG
LOEWE-OPTA MAGNET 3737W:
youtube.com/watch?v=ZSZBJ5sKQm8&list=PLy5M_tA9ux7J_hzDhnF8rs2c7wmgGfRlK
BRAUN ATELIER 3:
youtube.com/playlist?list=PLy5M_tA9ux7L3k5nPRvrk1aH764QRCTqE
LOEWE-OPTA TRUXA STEREO 4741W:
youtube.com/playlist?list=PLy5M_tA9ux7KhVk0KqPx0Wkh2KO_5f2fQ
GRAETZ COMEDIA 616:
youtube.com/watch?v=fwmW9k3TwNE&list=PLy5M_tA9ux7L5sAApLzV6xoYzmRNJpMW5
SABA FREIBURG W2:
youtube.com/playlist?list=PLy5M_tA9ux7IqvS-LshUGpE1D_WY6mrZe
GRAETZ MUSICA 4R417:
youtube.com/playlist?list=PLy5M_tA9ux7Ios98E59dWjwc2SRJyxwIn
You may also be interested in ...
CAPACITOR LEAKAGE TESTER:
youtube.com/watch?v=0pySErvzUIY&list=PLy5M_tA9ux7KWexvEjLB0SANSxQXi0zTS
