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Old 12th Jan 2017, 11:48 pm   #36
Radio Wrangler
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Join Date: Mar 2012
Location: Fife, Scotland, UK.
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Default Re: 2N3819 Junction gate field-effect transistor (JFET)

There are soe designs of HF transceiver where the same IF and IF filters and diode-ring mixers are used in one direction for receiving, and in the other direction for transmitting. These need 'bilateral' amplifiers which can be switched to amplify in one direction or the other. One design used for this, and which avoids lots of RF switches is to use a carefully chosen symmetric J-Fet and to switch the DC power feed from one end to the other.

David
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