Andrew Moore wrote:
into RX mode -- it took a deliberate keying event to, apparently,
force the firmware to re-evaluate the temp and disable the fan (which
of course causes a transmission and confuses the op on the other
I suspect this is because the AuxBus and peripheral microcontrollers are
Have you calibrated the KPA100 temperature sensor and set the quiescent
bias?
The KPA100 has a self-protection circuit in it that reduces power and
displays the message "PA HOT" if the heat sink temperature exceeds 85C
(185F).
I'm not sure it's possible to get the heat sink that hot in normal us
Wow! Thanks for all your replies. I think I'll take the advice offered by
several responders and set the fan for 'hi/lo' and stop worrying. I can
live with the noise using headphones much of the time anyway. Just thought
it was odd. Next time I open the rig up, I'll recheck the bias to the
Jim,
I run alot of CW contests and with constant CQing/exchanges you could
fry an egg on the heatsink. The existing cooling cannot keep up with
the heat generated. It looks a bit Frankenstein but I mounted (with
double back tape) a 12 volt 2.5" muffin fan on top of the heat sink. It
runs
Jim,
The fan does go on and off by sensing the temperature of the heat sink
(Q3 is the sensing element).
The temperature that the fan transition occurs is fixed, but will
operate at that fixed temperature only if CAL TPA is set correctly. CAL
TPA must be set to the actual temperature of the h
> When operating CW the
> fan turns on high during every transmission and the heat sink gets hot to
> the touch. I'm a ragchewer so my transmissions do run to several minutes
> and, regardless of power setting, the fan will kick on high after several
> minutes of transmitting.
...
> Does anyone ha
I searched the archives and didn't find anything on this, but from what I've
read, I think I may have a problem with my KPA100. When operating CW the
fan turns on high during every transmission and the heat sink gets hot to
the touch. I'm a ragchewer so my transmissions do run to several minut
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