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Palomar 200x horrible input vswrs
- Thread starter Staybolt
- Start date
The coil marked "L1" in the schematic is supposed to match the input of the driver tube to a 50-ohm radio.
Might have a look for that coil and see if someone molested it.
The manual doesn't say anything about the size or inductance of L1. My best guess would be around 1 microhenry, plus or minus.
I would have put a trimmer capacitor on the input side of L1 with the other side to ground. A 463 or 464 compression trimmer cap would be my first guess. Good chance that would improve the amplifier's input match all by itself.
You may also find that replacing L1 with a coil that has more turns will help. This is pretty much a cut-and-try sort of process, to improve the amplifier's input SWR.
Also could be that your driver tube has a problem.
But that's the short list of what I would check first.
I do hope you're using a really small radio. The 200X was designed for the wimpy tube-type base radios of the late 1960s. They would bust a gut to show a 3 Watt carrier and 11 or 12 Watt peaks. A modern base radio will tend to blow away that small driver tube.
73
Might have a look for that coil and see if someone molested it.
The manual doesn't say anything about the size or inductance of L1. My best guess would be around 1 microhenry, plus or minus.
I would have put a trimmer capacitor on the input side of L1 with the other side to ground. A 463 or 464 compression trimmer cap would be my first guess. Good chance that would improve the amplifier's input match all by itself.
You may also find that replacing L1 with a coil that has more turns will help. This is pretty much a cut-and-try sort of process, to improve the amplifier's input SWR.
Also could be that your driver tube has a problem.
But that's the short list of what I would check first.
I do hope you're using a really small radio. The 200X was designed for the wimpy tube-type base radios of the late 1960s. They would bust a gut to show a 3 Watt carrier and 11 or 12 Watt peaks. A modern base radio will tend to blow away that small driver tube.
73