Sec. 1 - Radio architectures overview Sec. 2 - My recent own homebuilt Radios

1. Regenerative Radio Workshop
by D.C.
2017/03/6 @Ultron

2. about.me
• Born in Kaohsiung, 1994
• FHCRC.102nd
• Studying EE @ FJU
• Joined Arduino.Taipei ( since 2013 )
•
•
• / Maker
My Blog : http://davidchensbase.blogspot.tw

4. Radio Spectrum
• IARU / CTARL / ARRL
• ITU / NCC / FCC
• LF / MF / HF / VHF / UHF / SHF / EHF [wiki]
• Spectrum Analyzer / FFT / Superheterodyne
• Cycle per second ( cps ) / Hertz ( Hz ) [wiki]
• 80 meters / 40 meters  Speed of light [link]
Image via : GWInstek

5. via : Flickr

6. via : NCC

7. Software Defined Radio ( SDR )

8. Shortwave Radio Antenna: Voice of America Delano Transmitting Station. ( via wiki )

9. A collection of early quartz crystal frequency standard units used in crystal oscillators, produced by Bell Labs/AT&T/Vectron International. ( via wiki )

10. A pair of 1968 Heathkit vibrators ( via wiki )

11. Architectures of Radio Receivers
• Crystal Radio ( )
• Tuned radio frequency ( TRF ) –
• Reflex receiver –
• Homodyne ( Direct-Conversion ) –
• ( Super ) regenerative – ( )
• Autodyne –
• ( Super ) heterodyne – ( )
• ( heterodyne / regenerative / autodyne ) detection
• / /
Image : A drawing of an early vacuum tube radio receiver and horn loudspeaker, from an advertisement in a radio magazine around 1922. ( via wiki )

12. Crystal Radio
• Crystal Radio ( )
• Cat's whisker detector ( Galena )
• Germanium transistors
• Crystal earpiece
• Needs well grounding
• Variable L/C
• Easy to make
• Sensitivity : Poor
• Selectivity : Poor
• Signal to noise ratio ( SNR ) : Poor
Image : Sketch of crystal radio set. ( via wiki )

13. Block diagram of a crystal radio receiver . ( via wiki )

14. A circuit of an inductively-coupled crystal radio receiver with impedance matching. ( via wiki )

15. Crystal radio diagram in 1922.
This circuit did not use a tuning capacitor, but used the capacitance of the antenna to form the tuned circuit with the coil. ( via wiki )

16. Ernst Jahnke crystal radio receiver, ca. 1924-1926. ( via wiki )

18. Tuned radio frequency ( TRF ) receiver
• Tuned radio frequency ( TRF ) receiver
• by Ernst Alexanderson, 1916
• RF Amplifiers / Active Filters
• IC ZN414 / MK484 / TA7642
• Neutrodyne receiver –
• by Louis Hazeltine, 1922
• Preventing oscillations
• Reflex receiver –
• by Wilhelm Schloemilch and Otto von Bronk, 1914
• Feedback loop
Image : Top view of the Leutz Transoceanic "Phantom" radio receiver with its cover removed, from 1927. ( via wiki )

19. Tuned radio frequency ( TRF ) receiver
• Pros
• Active band pass filter
• Cons
• Hard tuning, hard to build, large
• Sensitivity : Medium
• Selectivity : Poor
• Signal to noise ratio ( SNR ) : Medium
Image : The first Neutrodyne radio receiver, built by Louis Hazeltine and presented at the March 2, 1923 meeting of the Radio Society of America ( via wiki )

20. Block diagram of TRF receiver ( via wiki )

21. A typical tuned radio frequency ( TRF ) radio receiver circuit from 1924. ( via wiki )

22. Six tube radio receiver from about 1920. ( via wiki )

23. A basic circuit using the ZN414 AM detector transistor . ( via wiki )

24. A hand made matchbox radio using the MK484 IC ( via mds975.co.uk )

25. Tuning stage comparison between common TRF receivers and Neutrodyne receivers. ( via wiki )

26. The first neutrodyne radio receiver, presented by Louis Alan Hazeltine in a lecture on March 2, 1923
titled "Tuned radio frequency amplification with neutralization of capacity coupling" to the Radio Club of America at Columbia University. ( via wiki )

27. Block diagram of a simple single-tube reflex radio receiver ( via wiki )

28. Circuit diagram of a reflex receiver. One transistor amplifies both high frequency and low frequency. ( via wiki )

29. A handmade 2 transistor reflex radio. ( via )

30. Homodyne Receivers
• Homodyne receiver ( Direct-Conversion / Zero-IF )
• Mixer + Local Oscillator
• Low convert to DC
• Regenerative receiver
• by Edwin Armstrong, 1912
• No significant Mixer and LO
• Autodyne mixer ( Mixer / LO 2 in 1 )
• Hartley / Colpitts configuration
• Hysteresis –
• Nearly self-oscillating
• Regenerative control
Image : An early vacuum tube regenerative radio receiver from 1922. ( via wiki )

31. Super-regenerative Receivers
• Super-regenerative
• by Edwin Armstrong, 1922
• Quench oscillator in supersonic ( 30~100kHz )
• Oscillations were interrupted periodically
• Pros
• Simple, easy to make
• Cons
• Oscillator signal propagates through antenna
• Signal interfered by flicker noise
• Sensitivity : Excellent
• Selectivity : Medium
• Signal to noise ratio ( SNR ) : Poor
Image : American radio researcher Edwin H. Armstrong and his new invention, the superregenerative receiver in 1922. ( via wiki )

32. Block diagram of a regenerative radio receiver ( via wiki )

33. Vacuum tube regenerative receiver with Armstrong oscillator schematic. ( via wiki )

34. Homebuilt Armstrong one-tube regenerative shortwave radio with construction characteristic of the 1930s - 40s. ( via wiki )

35. Homebuilt Armstrong one-tube regenerative shortwave radio with construction characteristic of the 1930s - 40s. ( via wiki )

36. Schematic of the simple regen receiver
A Simple Regen Radio for Beginners – ARRL ( via )

37. A High Performance Regenerative Radio - Circuitsalad ( via )

38. Block diagram of a super-regenerative radio receiver ( ref )

39. A High Performance Regenerative Receiver
High Performance Regenerative Receiver Design - ARRL ( via )

40. CK-103 FM ( via )

41. Superheterodyne Receivers
• Heterodyne receiver
• by Reginald Fessenden, 1901
• Failed on the stability of LO ( ppt accuracy ) [wiki]
• Continuous Wave ( CW ) receiver
• Heterodyning Animation [link]
• Super-heterodyne receiver
• by Edwin Armstrong, 1918
• Supersonic IF stage ( 455kHz, 10.7MHz…etc )
• Stable, reliable until the transistor era [wiki]
• Regency TR-1
• Sony TR-52 / TR-55
Image : One of the first prototype superheterodyne radio receivers built by inventor Edwin Armstrong. ( via wiki )

42. Superheterodyne Receivers
• Pros
• Simple / stable enough to commercialize
• Excellent performance
• Cons
• More stages than a regen radio
• Tracking LO and Image filter
• Sensitivity : Excellent
• Selectivity : Excellent
• Signal to noise ratio ( SNR ) : Excellent
Image : American engineer Edwin with his new wife and a portable superheterodyne radio receiver. ( via wiki )

43. Block diagram of a superheterodyne receiver. ( via wiki )

44. Graph showing how a superheterodyne radio receiver receives a radio signal, shifting it down to the IF frequency. ( via wiki )

45. "All American Five" vacuum-tube superheterodyne AM broadcast receiver from 1940s. ( via wiki )

46. "All American Five" vacuum-tube superheterodyne AM broadcast receiver from 1940s. ( via wiki )

47. Vintage Regency TR-1 Transistor Radio, Made in the USA ( via wiki )

48. Vintage Regency TR-1 Transistor Radio. ( via wiki )

49. Inside view of Regency model TR-1 transistor receiver showing layout of components. ( via radiomuseum )

50. A copy of the patent of Regency TR1, by Richard Koch, assigned to I.D.E.A. ( via radiomuseum )

51. The Schematic diagram of the of Regency model TR-1 ( via radiomuseum )

52. S66D ( via )

53. TR-52 Sony ( ) 1955 1 . ( via wiki )

54. Double conversion superheterodyne block diagram ( via wiki )

55. DIY SDR HF Up-Converter forr RTLSDR by WA7JHZ . ( retrovoltage.com )

56. DIY SDR HF Up-Converter forr RTLSDR by WA7JHZ . ( retrovoltage.com )

58. • FM
•
• FM / AM
•
• ( RTL-SDR )
• 60MHz
• Manhattan-style Circuit Construction [Link]
• A Simple Regen Radio for Beginners – ARRL [Link]
Image : IC – CD9088 AM / FM

59. FM SCAN RESET

60. FM Transmitter Bugs

61. Astable Multivibrator Kit

62. ( 2014~2015 ) Buck/Boost/Linear Regulators, more Crystal Radios and FM Txs

63. ( 2015~2016 ) More Radios ( RX ) / Audio Amps & Testing Tool

64. A Simple Regen Radio for Beginners
By Charles Kitchin, N1TEV
• BJT ( 2N2222 )
• LM386
• Hartley : 2L1C
• Fine Tune
• FM !?
•
• 5.6~11.9MHz ( Pi-FM-RDS )

65. 2N2222

69. High Performance JFET Regen
by Ray Charles Ring, circuitsalad.com
• Common Gate Antenna Buffer
• JFET
• LM317 5V
• LM386 ( TDA7052 )
• 50K JFET LM386
• Colpitts :1L2C
• PCB
• Toroid
• [Link1] [Link2]
• 5~18MHz

70. T50-52 ( / ) 5uH

73. T37-6

74. / L

76. Poor man’s solutions
• Calculators
• Toroid coil calculator [Link]
• Air coil calculator [Link]
• LC tank Frequency Calculator [Link]
• Google Search Plot [Link]
• Android APP - ElectroDroid [Link]
• Simulators
• GNURadio [Link]
• Falstad Circuit Simulator [Link]
• Audacity [Link]

77. • Measurements
• Cheap sound card as a signal generator
• Arduino
• Frequency Generator [Link]
• Frequency Counter Library [Link]
• FHT Library [Link]
• Serial Plotter [Link]
• Pi-FM-RDS Project [Link]
• AVR Component Tester [Link]
• RTL-SDR / SDR-Sharp [Link]
• Making
• Self-designed Manhattan Circuit Helper [Link]
Poor man’s solutions

78. References
• Wikipedia
• Radio receiver [Link]
• Crystal Radio [Link]
• Tuned radio frequency receiver [Link]
• Neutrodyne receiver [Link]
• Reflex receiver [Link]
• ZN414 [Link]
• Direct-convertion receiver [Link]
• Regenerative receiver [Link]
• Armstrong oscillator [Link]
• Superheterodyne receiver [Link]
• Edwin Howard Armstrong [Link]
• Regency TR-1 [Link]
• Sony TR-52 [Link]
• Blogs
• “ ” [Link]
• [Link]
• Radio Experimenter's Blog [Link]
• Circuitsalad.com [Link]
• Dave Richards AA7EE [Link]
• YouTube Channels
• W2AEW [Link]
• Mr Carlson's Lab[Link]
• EEVblog [Link]
• Afrotechmods [Link]
• RimstarOrg [Link]

79. The End
Thanks for Listening