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Project Notes

#123 HX-6B AM Receiver Kit

Build and analyse the HX-6B superheterodyne AM MW radio receiver kit.

The Build


Just my notes on a build of a HX-6B kit from a seller on aliexpress.

A superheterodyne receiver (often shortened to superhet) uses frequency mixing to convert a received signal (at a variable frequency) to a fixed intermediate frequency (IF) which can be more conveniently processed with known gain and selectivity.

Tutorials and Resources

Building and Aligning HX 6B AM Kit Radio by shango066



Ref Part Notes
V1,2,3 9018 NPN transistor
V4 9014 NPN transistor
V5,6 9013H NPN transistor
LED 3mm LED  
T1 transformer  
T2,3,4 transformer  
T5 transformer  
BL 8Ω speaker  
R6,8,10 100Ω resistor  
R7,9 120Ω resistor  
R11 330Ω resistor  
R2 1.8kΩ resistor  
R4 30kΩ resistor  
R5 100kΩ resistor  
R3 120kΩ resistor  
R1 200kΩ resistor  
RP 5kΩ pot  
C6 0.47µF electrolytic cap  
C3 10µF electrolytic cap  
C8,9,10 100µF electrolytic cap  
C2 682 6.8nF ceramic cap  
C1 103 10nF ceramic cap  
C4,5,7,11 223 22nF ceramic cap  
Ca,Cb CBM-223P variable capacitor  




Circuit Design

The HX6B is a superheterodyne design with a single IF stage. The design basically maps out as follows:

  • RF Filter: T1, Ca antenna tuner
  • RF amp: V1
  • Local oscillator and Mixer: T2, Cb
  • IF Filter and Amp: T3, V2
  • Demodulator: T4, V3
  • Audio amp: T5, V5, V6 push-pull class B

The Schematic

Credits and References

Project Source on GitHub Project Gallery Return to the LEAP Catalog

This page is a web-friendly rendering of my project notes shared in the LEAP GitHub repository.

LEAP is just my personal collection of projects. Two main themes have emerged in recent years, sometimes combined:

  • electronics - usually involving an Arduino or other microprocessor in one way or another. Some are full-blown projects, while many are trivial breadboard experiments, intended to learn and explore something interesting
  • scale modelling - I caught the bug after deciding to build a Harrier during covid to demonstrate an electronic jet engine simulation. Let the fun begin..
To be honest, I haven't quite figured out if these two interests belong in the same GitHub repo or not. But for now - they are all here!

Projects are often inspired by things found wild on the net, or ideas from the many great electronics and scale modelling podcasts and YouTube channels. Feel free to borrow liberally, and if you spot any issues do let me know (or send a PR!). See the individual projects for credits where due.