Re: [Elecraft_K3] K3/P3 video display on AM vs SSB


In general, the power level of a voice signal displayed on the P3 will be less than the average power. The reason is that each display point on the P3 is only showing a portion of the total power.

You would see a similar effect on the K3 or other receiver if you monitored an SSB signal with a narrow CW filter. The S meter would read lower since only a portion of the signal is within the passband.

If an AM signal is modulated with a single-tone sine wave at 100% modulation, then each sideband will be -6 dB from the carrier, and it will show that way on the P3. But with voice modulation it will be much lower, both because of the effect I just mentioned and because the average modulation is less than the peak.

Alan N1AL

On 06/30/2015 08:23 AM, farrerfolks@... [Elecraft_K3] wrote:

One other thing Grant is that when a BC station transmits a single tone,
the sidebands at averaging or open should be 6 dB down. It never is?
As a side note, my HP 8920 shows a proper power distribution in the
sidebands? Is what I am observing be some artifact of the DSP in the
K3/P3 algorithm?

Mel, K6KBE

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