Tag: electronics
-
Evolution of Radio Receivers Part 3: Build a Classic 6-Transistor Superhet Pocket Radio
In Part 3 of the Evolution of Radio Receivers series, we build and align a classic 6-transistor AM superhet pocket radio. Complete schematic, parts list, construction tips, step-by-step alignment, and real-world listening test results. Perfect hands-on project for electronics hobbyists and students.
-
Tektronix 494P Spectrum Analyzer Repair – Display blank
Several months ago I fixed the video offset problem of my HP8562A. (See the post: HP8562A Spectrum Analyzer Repair: Fixing Video Offset / Display Issues. ) Last week my Tek 494P refused to work – the display was blank after power on. A quick diagnosis revealed the following: Troubleshooting I remove the instrument cover to…
-
Evolution of Radio Receivers – Part 1: The 2-Transistor Reflex TRF Receiver
In the late 1950, transistor pocket radios emerged. The best performers employed superheterodyne architecture and were expensive. This resulted in another market for lower cost radios using the Tuned Radio Frequency (TRF) architecture which used fewer transistors. Perhaps the most ingenious TRF design was the 2-transistor reflex circuit which had sufficient gain to drive a…