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IC-746 PRO Repair - Low TX Power on all Bands [message #1236] Tue, 17 January 2012 00:23
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Registered: December 2004
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On Checking an IC-746PRO with low output power, it was found that the pre-predriver transistor tr Q1 (2SK2973)had overheated because of insufficient heatsinking (this has been covered many times before). The transistor was replaced only to find no improvement. Further investigation proved that the small choke L2 100uh had gone open circuit.

I replaced the choke and all has been well with 100w output on all bands. Check the standing current of this transistor as the specs per the w/manual is incorrect. The standing current of 500ma as per another published article has proved perfect.

The IC746-PRO is again functioning perfect - better than before!

Author: zS2ACP
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