PW-1 and ALC

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  • Updated 2 years ago
I have my Flex 6300 bandswitching with my PW-1 Amplifier using Ed W2PH's bandswitching box. But now I have a question about the ALC from the Flex to the amplifier.

It's very easy to get a full Kilowatt out of the amplifier, but I'm doing it with only 22 Watts on 40 meters.  The amplifiers ALC is fully counterclockwise. I'd much prefer running 100 Watts in if I could for protection of the amplifier.

The amp tunes and adjusts the Amplifer's AGC normally with an Icom. Set at 100 Watts and adjust for full power out.

The question I have is should I connect the ALC out from the amp to ALC in on the radio?Some folks have, but I'm concerned because the Hardware manual says the Radio's ALC can be damaged if ALC goes below -4 Volts, and the PW-1 manual says it goes between 0 and -10 Volts. 

Or is DDUtil in my future?
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Michael Coslo

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  • Just don't want to release the sacred smoke

Posted 2 years ago

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NX6D Dave

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I'm in no position to know if you should or should not be using ALC, but a simple solution to the problem of the two max voltages would be to put a little voltage divider between the two units.  Map the 0 to -10V generated by the amp to 0 to -4V expected by the radio.
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David Decoons wo2x, Elmer

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If 22 watts gives you 1000 watts out on that band, why would you want to run 100 watts and ALC to cut it back to 22 watts? You would be depending on the radio to cut back power based on feedback from the amp. That is a disaster waiting to happen.

If you are concerned about overdriving the amp why not just run DDUtil and use the Auto Drive feature to set power on each band to the level needed to drive the amp. You can also enable DDUtil to toggle the TX1 out of the radio to the amp key in on the amp to follow DDUtil operate/standby button.

That way when you click operate the radio will key the amp and set drive to maximum you set for that band. When you click standby it disables the keying line and sets radio to 100 watts out.

Dave wo2x
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Michael Coslo

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It isn't a matter of wanting to cut it back with alc. The idea of running the radio at max output is to avoid having a condition where the radio is putting out more than the amplifier will handle. So it looks like I just throttle it via external software, and live with that.
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I use the CT-17 to connect amp to computer. Then set the ALC(pre instructions PW-1 manual)   by adding drive till the out put is 1000 and the ALC on the PW-1 is in the center on the meter like is suppose to be. Then set the Amp drive on DDUTIL so as not to over drive. You will fine it does not take as much to drive from the Flex as say a Icom radio. My drive is 40 watts for 900 to 1000.