[Elecraft] K3 power output on SSB

[Joe Subich, W4TV]

> No, please, this is not a power calibration issue!

Bull ... I have seen it and can recreate it at will. 

If the wattmeter is not properly calibrated and the 
transmit gains are off, the bower setting routines 
do not act correctly.  With the transmitter properly 
calibrated I see less than .5dB "undershoot" (more 
than 95 W when commanded for 100W) when changing bands. 

If I intentionally miscalibrate the wattmeter (as I 
did by accident when building the unit) and then do 
the transmit gain calibration with an  inaccurate 
wattmeter, the radio will display a 2 to 3 dB undershoot 
(50 to 60 watts) when first changing bands.  

73, 

   ... Joe, W4TV 
 


> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net 
> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of ab2tc
> Sent: Monday, March 29, 2010 7:00 PM
> To: elecraft at mailman.qth.net
> Subject: Re: [Elecraft] K3 power output on SSB
> 
> 
> 
> Hi,
> 
> No, please, this is not a power calibration issue! A huge 
> number of K3 users have complained about this propensity of 
> the SSB power to aim "conservatively" for 50-80% of the 
> requested peak power and then slowly, very slowly climbing up 
> to the requested power. Once reaching 100% it stays there 
> until you perform some kind of QSY operation other than just 
> turning the wheel. It is not a huge irritant to me, but an 
> irritant nonetheless. If I am in a big rush to have full 
> power on SSB after a QSY, I switch mode to TX data FSK D, do 
> a quick squirt of TX and I have instant full SSB peak power.
> 
> AB2TC - Knut
> 
> 
> Joe Subich, W4TV-4 wrote:
> > 
> > 
> > 
> >> When I whistle to mic and tune my linear amplifier, I notice
> >> that last watts going up very slowly. Without linear I tested 
> >> and sometimes first 80 watts out normally but from 80 to 100 
> >> watts it takes about 2-3 seconds.
> > 
> > Sounds like a power calibration issue.  Double check the K3
> > wattmeter calibration, the amplifier gain calibrations and 
> > TXG VCE.  
> > 
> > 73,
> > 
> >    ... Joe, W4TV
> >  
> > <snip>
> > 
> 
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