http://elecraft.85.s1.nabble.com/KPA1500-Thermal-problems-tp7656375p7656378.html
What output power did that reduce too ultimately, is 105c the design temp
> " I rode the drive power downward as the power increased to stay below the
> trip point of 105c."
>
> Should have been "as the temperature increased"
>
> jim ab3cv
>
> On Mon, Nov 11, 2019 at 9:03 AM Jim Miller <
[hidden email]> wrote:
>
> > I participated in the WAE RTTY contest this past weekend and was having
> > problems with thermal tripping.
> >
> > I have resonant antennas for 80, 40 and 20m and had SWR between 1:1 and
> > 1.2:1, power nominally set between 1400-1500w.
> >
> > I found that I couldn't repeatedly CQ without temperature creeping up so
> I
> > paused to around 50% duty cycle to stop that.
> >
> > However when sending QTC which amount to about 200 characters the
> > temperature would rapidly increase and eventually thermal trip.
> >
> > I took several actions to try to compensate:
> >
> > I opened the shack windows and bundled up. Shack then stayed at 60f or
> > below.
> > I immediately manually cranked the fan speed to max (5) when started to
> > send QTCs.
> > I rode the drive power downward as the power increased to stay below the
> > trip point of 105c.
> >
> > Upon taking all these actions I was able to eventually send the QTC
> > packets but it was unnerving and unexpected.
> >
> > This is a low serial number KPA1500 but with latest production firmware.
> >
> > What have others seen?
> >
> > 73
> >
> > jim ab3cv
> >
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