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IC-7300 USING EXTERNAL ANTENNA TUNER JC-4
Inside a clip-on choke/suppressor was plenty room for installing resistor and diode, so they are well protected .
IC-7300 IN LINE WITH ATU AND PA
When one use the TUNE button (or PTT) of an IC-7300 in line with a linear amplifier and automatic antenna tuner, the amplifier is activated and overload the ATU. Often the ATU goes faulty one has experienced.
If IC-7300 is "ON" pin "Key" of Tuner Control Socket is "high" and Rly is closed so that the amplifier can be operated via pen "SEND" of the Send Control Jack. The moment that "TUNER" buton is pressed, pin "Key" goes low, Rly disconnect "SEND" and IC-7300 activates the ATU a couple of seconds with about 10 W. Then "Key" goes "high", Rly closes and the PA can be used.
SYSTEM 2 is in progress!