QCX assembly Rev 1.08
25
3.18
Install 1N5819 diode
This diode D3 is the larger diode with a black body, and a white stripe. It is installed horizontally.
Again, it must be orientated correctly, with the white stripe on the diode matching the white stripe
on the PCB.
This diode protects the radio against reverse polarity. So that if you connect the power to the
board the wrong way around, you do not destroy it. A Schottky diode is used because the forward
conducting voltage drop is less than an ordinary diode. However, on transmit, the voltage drop
across this diode can still be up to 400mV. This reduction in voltage does slightly decrease the
output power.
IF you want to squeeze every last milliwatt of output power out of the radio, and IF you trust
yourself NEVER to connect the power supply in reverse by mistake, then if you just install a
jumper wire instead of D3, it would give you a little higher RF power output.
Summary of Contents for QCX 5W CW
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Page 10: ...QCX assembly Rev 1 08 10...
Page 12: ...QCX assembly Rev 1 08 12...
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Page 105: ...QCX assembly Rev 1 08 105...
