[Elecraft] P3 S meter variance

[Al Lorona]

An SSB signal that is S9 on the K3's S-meter is not going to measure S9 on the 
P3.

The reason is that an SSB signal has bandwidth, and the sum of all of the signal 
within that bandwidth is what the K3's S-meter reads.

You would have to add up all of the power of the SSB signal on the P3's display 
to equal S9. This mathematical operation is called integration. The P3 does not 
do integration.

Therefore, make all of your calibrations with CW signals, and live with the 
apparent discrepancy on SSB.

Al  W6LX


 



________________________________
From: Roy Morris <w4wfb at carolina.rr.com>
To: elecraft at mailman.qth.net
Sent: Sun, January 16, 2011 3:28:53 PM
Subject: Re: [Elecraft] P3 S meter variance

I have found that -8.9 LVL CAL (transfer gain) is the setting for an S9 reading 
on my P3 using my XG-1.  The readings track right well as long as they are not 
stronger than S9+20.  Signals over this on the K3 S meter are just not correct 
on my P3.  If I change the LVL CAL (transfer gain) to around -27, the strong 
signals are then correct.  This tells me there are no absolute settings that 
will make the P3 correct at all SSB signal strength levels.  YMMV - Your LVL CAL 
settings will no doubt be different from mine.  Roy Morris  W4WFB