[Elecraft] Data mode and filters

[Joe Subich, W4TV]

 > No, but they/we can put a calibrated peak-reading wattmeter like the
 > LP-100A in line with the feed to our antennas.

While a peak reading wattmeter like the LPA-100 is a good step, it
still does not respond to instantaneous peaks.  Most "peak reading"
wattmeters will show peak values that vary depending on the PSK31
datastream and never show the true instantaneous peak.

 > And last I looked, few hams run much power with PSK-31.

They have to do that or they would be clipping terribly in the final
amplifier stage (or in the transmit IF of some poorly aligned rigs).
They certainly can't push the rigs to 100W as your tests would imply.

73,

    ... Joe, W4TV


On 2015-05-15 12:44 PM, Jim Brown wrote:
> On Fri,5/15/2015 9:10 AM, Joe Subich, W4TV wrote:
>> The vast majority of amateurs do not have calibrated scopes on the
>> output of their transmitter/amplifier to keep the instantaneous peak
>> output below the onset of compression in the final stage of power
>> amplification.
>
> No, but they/we can put a calibrated peak-reading wattmeter like the
> LP-100A in line with the feed to our antennas.
>
> And last I looked, few hams run much power with PSK-31. As both my
> measurements and K6XX measurements clearly show, IMD in the K3 drops
> significantly below full power.
>
> 73, Jim K9YC
>
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