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Build Your Own Transistor Radios by Ronald Quan

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Chapter 5Low-Power Tuned Radio-Frequency Radios

The very first radios were tuned radio-frequency (TRF) radios back in the early twentieth century. TRF radios were made commercially from the beginning of amplitude-modulation (AM) radio to the twenty-first century. As of 2012, there are still commercially made TRF radios for the AM section of an AM/FM radio, such as the Kaide Model KK-205 radio that sells for about $5 to $6 on eBay. Also the Kaide Model KK-9 AM/FM/SW (shortwave) radio that sells for about $7 on eBay has a TRF AM radio section while having a superheterodyne circuit for the FM and SW bands. This chapter will explore TRF radios that drain very little power, and a number of designs will be presented.

Design Considerations for TRF Radios ...

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