#123 HX-6B AM Receiver Kit
Build and analyse the HX-6B superheterodyne AM MW radio receiver kit.
Notes
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
Parts
| 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
Credits and References
- the kit from a seller on aliexpress
- Superheterodyne Receiver - wikipedia
- Introduction to the Superheterodyne Receiver - by Lloyd Butler VK5BR
- Block Diagram of Superheterodyne Receiver Radio - Ian Pool. A good description of the modules.
- Radio Receivers Book - Chapter 4 Superheterodyne Radio Receivers - Miomir Filipovic
- Superheterodyne: BJT AM receiver - fascinating project notes by He Yong Li