Archive for the ‘Audio’ Category:

2025-02-01 Morse Code Text Encoder, Translator, Converts Into Audio File.

https://morsecode.world/international/translator.html

2024-12-15 Hot Arcs From Flyback Transformers Play “Take On Me” by Ah-hah

Hot Arcs From Flyback Transformers Play “Take On Me” by Ah-hah. The flybacks are driven by a power amp made for driving these flyback transformers.  Looks like just a few turns of 18 AWG wire are wrapped around the bare ferrite cores.   A highly effective plasma speaker, better sounding than a Tesla coil. https://www.facebook.com/franzolielectronics/videos/272985324667136/?mibextid=9drbnH&s=yWDuG2&fs=e

2024-11-08 RF Amp Using BD139 Power Transistors

He has a strong Aussie accent, a bit hard to understand.  It’s a 28 min. YouTube video.  He says BD139s have a fT of 250 MHz, but the datasheet I have does not specify any fT because the D in BD139 means they are a low frequency device, not meant for VHFs or RFs in

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2024-10-08 Transistor History – Raytheon, CK722, etc.

Long article https://sites.google.com/site/transistorhistory/Home/us-semiconductor-manufacturers/raytheon-part-one-2 A comprehensive history of the Raytheon corporation.  Also information about other companies.

Delia Derbyshire, Creator Of Dr Who Theme

Unrecognized early creator of electronic music. https://www.facebook.com/reel/1778652559335515?mibextid=9drbnH

2024-05-26 Researchers Invent Mini Tuneable YIG Filter 3.4 to 11 GHz for 6G Datacomm

This is an interesting article: mainly about a miniature Tuneable YIG – yttrium-iron-garnet – filter that could replace many fixed filters. Quote “”Wireless devices use different filters for different frequencies, with the effect that covering all frequencies or bands requires large numbers of filters that take up substantial space. (The typical smartphone includes upwards of

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2024-05-08 Steve Gibson’s Validrive checks fake drives for total storage space

Have you got a USB disk drive or flash drive that was sold at a price so low it was “too good to be true”?  Steve Gibson’s Validrive will do spot checks to see if the SSD or flash drive is really what it claims to be.  Fake drives are sold for cheap and the

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2024-04-10 FM Regenerative Receiver Using MPF102 JFET

A basic one transistor regen receiver uses an MPF102 JFET to give the regenerative gain.  Also uses two transistors to amplify the audio to drive an earphone.  https://www.circuitbasics.com/what-are-fm-receivers/

2024-03-29 FM Crystal Set Uses Helical Resonator For Tuning

This is a long article but a very interesting project.  It uses HSMS-2850 Schottky detector diodes in a discriminator.  He uses WE 1200 ohm sound powered headphones.  He’s Canadian. https://electronbunker.ca/eb/FMCrystalSet.html

2024-03-24 Signal Distortion From High-K Ceramic Capacitors

A good article about signal distortion in a Butterworth low pass opamp filter using C0G and X7R MLCCs.  https://www.edn.com/signal-distortion-from-high-k-ceramic-capacitors/

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