New KPA 500 Questions: Idle HV and Info button

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New KPA 500 Questions: Idle HV and Info button

kb7our
Newly assembled AMP. Two quick questions -

1) At 120V using green tap, idle HV is ~87V which is just over the
recommended 85 but not enough to trigger a fault. This setting provides just
over 60V at 500W+. Also keeps the amp hum nice and quiet vs the other 2
louder tap options which do keep idle HV under 85 but < 60V under load. Ok
to operate a little out of the upper V range using the green tap?

2) Also, I found no reference in searches or manual for the INFO button.
Looks like it's not being used for anything - do I have this correct?

Thanks!

Wade



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New KPA 500 Questions: Idle HV and Info button

ANDY DURBIN
1) At 120V using green tap, idle HV is ~87V which is just over the recommended 85 but not enough to trigger a fault.

I don't know if 87 V is OK or not but my unloaded voltage is 79.6 V with mains supply at 120.4 V.  That gives 63 V at 10 A.   PA voltage will vary with current and current depends on efficiency which will vary with frequency and quality of antenna match.

e.g.

             TX freq = 1840500 Hz
              PA voltage = 63.7 V
              PA current = 10.2 A
              PA input = 649 W
              Drv pwr = 027 W
              RF out = 517 W
              PA diss = 132 W
              PA effic = 79%



2) Also, I found no reference in searches or manual for the INFO button.  Looks like it's not being used for anything.

I press INFO to clear any fault that may have tripped.  I initially expected it to display more info on the fault but it doesn't.

73,
Andy, k3wyc

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Re: New KPA 500 Questions: Idle HV and Info button

kb7our
Thanks, Andy. I remembered that I have an unused 240V dryer outlet one room
over from the shack that I will be using which will be ideal for the amp.
After a revisit of the manual I did see where the INFO button displays
errors.

Wade



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