Does anyone have the correct bias setting for this radio. I have all the other alignment info.
Thanks GT
Thanks GT
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RCI 69 Base Plus V2 bias setting
- Thread starter Green Tiger
- Start date
40ma for all three adjustments points. I was under the impression that mosfets were set by voltage
NEVER set bias by voltage. The service manuals suggesting that method are wrong because mosfets with the same part number can have very different drain currents for a given gate voltage. ALWAYS set mosfet bias by drain current.
Bias setting is all about device current draw with no drive. Manufacturing tolerances cause the exact gate voltage needed to differ from one part to the next. That's why there is a trimmer pot, to compensate for the gate-voltage difference from one MOSFET to the next. Yeah, measuring gate voltage is easier than breaking the drain circuit to measure current, but it won't deliver an accurate result.
73
73
I usually adjust bias by measuring the current going to the radio. With the mic keyed in ssb with no audio, watch the current to see when it starts to conduct. Then turn it down until it doesn't conduct. You want it right on the edge of turning on.