If the onboard meter _thought_ the K3 was making the requested
power, that would be one thing. But in this case the onboard
meter thinks it's putting out 2x the power, which it is.
It depends on what part of the system thinks what. In this
case the MCU is reading a given value but
Joe Subich, W4TV-4 wrote:
Perhaps
the power metering should be derived from a DSP based spectrum
analyzer?
Accept the fact that the power level control is relative. If
Wayne and Lyle can improve on it that's great. However, trying
to hold .1 dB or even 1 dB accuracy from 1
Joe
Thank you for pointing out the difficulties in setting average power
across a range of modulation types.
Whatever the peak/average ratio of the modulation, the output power from
the PA is peak limited - so wouldn't the answer be a K3 power meter and
power control that shows/sets peak
Setting a power control calibrated for CW and expecting that level to be
accurate for PSK31 or any other arbitrary digital modulation is complete
folly and utter hubris.
I also read another post that the K3 watt meter is an average power
responding device and there in lies a problem of setting
One way to resolve the confusion over interpreting the K3's power output
display would be to implement a peak reading/average reading feature, like
that in the s-meter. The S-meter can show both peak and average signal
strength simultaneously. Perhaps something like that could be done with the
Peter Connors, F5VNB wrote:
Joe
Thank you for pointing out the difficulties in setting average power
across a range of modulation types.
Whatever the peak/average ratio of the modulation, the output power from
the PA is peak limited - so wouldn't the answer be a K3 power meter and
If what Joe claims is true then this is a more serious issue
than even I imagined, since it affects SSB operation as well
as data modes. It would be so serious that I suspect he is
wrong about it.
If I dial up 100W in SSB or data I expect the power to be
limited to 100W PEP, not 100W
Whatever the peak/average ratio of the modulation, the output
power from the PA is peak limited - so wouldn't the answer be
a K3 power meter and power control that shows/sets peak rather
than average power?
While that might be a solution, it causes other problems. The
wattmeter is used
Joe Subich, W4TV-4 wrote:
Since the K3 power control is based on average power and not
instantaneous (absolute) peak power, the power level (both
requested and reported) can not be relied on as a gauge of
proper operation unless the user knows with certainty how much
headroom is
While that might be a solution, it causes other...
Why should the firmware not be able to both? Assuming that there are no
hardware limitations, I would think it should fairly easily be possible
to do peak readings and average readings as needed by the firmware, in
the firmware, for the
AD6XY wrote:
Joe Subich, W4TV-4 wrote:
Since the K3 power control is based on average power and not
instantaneous (absolute) peak power, the power level (both
requested and reported) can not be relied on as a gauge of
proper operation unless the user knows with certainty how
Peter Connors, F5VNB wrote:
To assert that every K3 owner needs an oscilliscope or laboratory grade
peak reading meter in order to ensure that they never exceed a given peak
power because the K3 internal circuits are incapable of doing so is a very
serious criticism indeed.
I'm not
G4LNA wrote:
I'm not asserting anything, what I said applies to any rig you care to
mention, I don't believe meters. No matter what magic wizardry circuits or
software is contained in the rig to deceive to meter into reading power,
you can't beat seeing the peak power reading on an
I can report the identical problem to that which Julian describes. I don't
remember the firmware version where this started but it was certainly not
always the case that the actual power output in Data A mode was so much
greater than the requested power. I can set for 5W and get a displayed (K3
I can report the identical problem to that which Julian
describes. I don't remember the firmware version where this
started but it was certainly not always the case that the
actual power output in Data A mode was so much greater than
the requested power. I can set for 5W and get a
So? Reduce the power you request to get the required output.
What other radio has a calibrated power output control?
The wattmeter in the K3 is relative ... there is a documented
power vs. frequency slope. Testing seems to indicate there
are also nonlinearities with changes in peak to
There's a thread on a related topic (PSK TX IMD) on the Elecraft K3 list
at Yahoo Groups.
Rich VE3KI posted some measurements done with the PSKMeter that show
poor IMD above about 50W.
I've suggested he re-run the tests with a 3dB pad to compare
apples-to-apples and reduce the effect of
Joe Subich, W4TV-4 wrote:
So? Reduce the power you request to get the required output.
What other radio has a calibrated power output control?
If you want a bloody laboratory grade meter, buy a laboratory
grade power meter.
Er, my K2 has always been able to do this. My FT-817
Leigh L. Klotz Jr WA5ZNU wrote:
There's a thread on a related topic (PSK TX IMD) on the Elecraft K3 list
at Yahoo Groups.
Rich VE3KI posted some measurements done with the PSKMeter that show
poor IMD above about 50W.
I've suggested he re-run the tests with a 3dB pad to compare
The point is it was providing the correct power output levels
before the last couple of firmware revisions. Something
changed that made it go from putting out approximately the
right power level, to putting out WAY TOO MUCH (i.e. causing
splatter) power.
Not true ... in spite of
Rich VE3KI posted some measurements done with the PSKMeter
that show poor IMD above about 50W.
The K3 wattmeter is essentially an average responding device.
PSK31 has a relatively high peak to average ratio ... as much
as 6 dB or more depending on the particular data but generally
running
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