Hi All,
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I went through the power optimization exercise on my QMX+ last night.
At first power on, I was only getting near 5W on 160m and 80m.
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160m ? ?5.85
80m ? ?4.39
60m ? ?2.00
40m ? ?3.28
30m ? ?1.78
20m ? ?2.91
17m ? ?3.06
15m ? ?3.03
12m ? ?2.33
10m ? ?2.23
6m ? ?1.70
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After looking at the LPF sweeps it seemed obvious that the cutoff was too low on all the upper bands.
This seems to imply that the inductance of coils in the low pass filters was too high.
Sure enough, after spreading the turns on those inductors the output power increased on most bands.
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160m ? ?5.89
80m ? ?4.90
60m ? ?3.76
40m ? ?3.69
30m ? ?4.36
20m ? ?3.21
17m ? ?2.71
15m ? ?4.81
12m ? ?2.92
10m ? ?4.01
6m ? ?2.35
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The passbands on 20m and 17m are not flat making it rather tricky to adjust.
Sadly, on 17m I seem to have hit a tiny notch in the passband after adjusting the turn spacing.
I don't yet understand why the passband is not flat.
These results may be good enough.
More fiddling may help but...
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It looks like there would be more room for adjustment if I removed turns from almost all the LPF inductors.
Is that consistent with the findings of others?
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73, Mike KK7ER
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