John,
Were you able to set the bias on the KPA100 with the pot set to about
1/3 rotation? (yes it is related).
The tpa value seen in the K2 CAL menu follows the temperature variation
of the heatsink as sensed by the base to emitter junction of Q3.
Measure the voltage for TSENSE at KPA100 U1 pin 5. It should be
somewhere close to 0.6 volts at normal heatsink temperatures. If it is
wildly different, check R5, R6 and Q3 to be certain they are properly
placed and well soldered.
73,
Don W3FPR
NQ3RP wrote:
> I've checked out the KPA100, have it operating on the hi Amp power supply and
> it works great except for these two items:
>
> 1. In Fan Menu, going to LoHi setting - the fan doesn't run. If I go
> to the high it kicks in and runs.
> When I first turned on the K2 (back when I was using the normal
> 12v supply it ran but after
> awhile it quit.
> 2. In the TPA for the temperature will not change from 0 c. turning
> the encoder.
>
> Can't for the life of me figure out what might be causing this. Is it some
> other parameter I have to change before doing these. Anyone experience
> this?
>
>
> John
> NQ3RP
>
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