This starts out as a "what's wrong with this picture" sort of story. If you haven't looked inside of a few Cobra 2000GTL base radios you might miss the large empty space all around this power transformer. The reason is that the factory-original transformer is nearly double the size of this one. It's larger than the ones used in every other Uniden-made 40-channel SSB base radio. Has to be, since the primitive chip technology inside the frequency counter/clock module pulls nearly a third of the radio's total power requirements. And the correct transformer is unique to the Cobra 2000. No other Uniden-made CB base used one that big.
Next question is "what happened to the original power transformer? They don't go bad that often."
Don't know, but the new final transistor and the wiring changes alongside it are a clue.
My suspicion is that the added current demand of the MOSFET final caused the fuse to trip repeatedly. Until a bigger fuse was installed, and the transformer got roached.
Don't know, just a theory.
And maybe lightning hit the utility pole across the street.
So here's the solution this century.
The 50-Watt size just fits. Just. The toggle switch interfered with the new supply's fit and was removed from the rear panel. It served to shut off the clock/counter and reduce power demand.
No need for that now.
And while we're in this radio, here's how to implement the MotorMouthMaul "slide-in" when you key the mike. Bear in mind this won't work if the clarifier has been modified to actually use on sideband. The clarifier HAS to be stock for this trick to work as you see it.
But the radio's owner doesn't care about sideband. The MOSFET final has no fixed bias, just the "companion part" gate bias you get from the carrier in AM mode. His radio is set up to suit how he chooses to use it.
And now it won't groan, squeal and dim the lights when he keys the mike.
73
Next question is "what happened to the original power transformer? They don't go bad that often."
Don't know, but the new final transistor and the wiring changes alongside it are a clue.
My suspicion is that the added current demand of the MOSFET final caused the fuse to trip repeatedly. Until a bigger fuse was installed, and the transformer got roached.
Don't know, just a theory.
And maybe lightning hit the utility pole across the street.
So here's the solution this century.
The 50-Watt size just fits. Just. The toggle switch interfered with the new supply's fit and was removed from the rear panel. It served to shut off the clock/counter and reduce power demand.
No need for that now.
And while we're in this radio, here's how to implement the MotorMouthMaul "slide-in" when you key the mike. Bear in mind this won't work if the clarifier has been modified to actually use on sideband. The clarifier HAS to be stock for this trick to work as you see it.
But the radio's owner doesn't care about sideband. The MOSFET final has no fixed bias, just the "companion part" gate bias you get from the carrier in AM mode. His radio is set up to suit how he chooses to use it.
And now it won't groan, squeal and dim the lights when he keys the mike.
73
