[Elecraft] K3 - Are the bands cleaner with all the K3s being used?

[Jim Brown]

On 1/13/2012 5:47 AM, Lou Kolb wrote:
> It really is amazing!  I never payed much attention to it with the old
> TS-440 but, since I've had the K3, its quite revealing to tune above the
> signal and note the drop-off.  The difference between rigs can be dramatic!

YES!  With so many contesters using K3s, a dirty rig with a lot more 
phase noise and clicks really really stands out.like a you know what in 
the punch bowl. Far more contesters can squeeze into the same limited 
bandwidth when each is only about 350 Hz wide 50 dB down, which is how a 
K3 shows up on my P3, as opposed to 3,000 -4,000 Hz wide for rigs that 
used to be the contester's standard.

It's important to realize though that a dirty or badly tuned power amp, 
or overdriving an amp and using ALC to control the amplifier's power 
output is also a great recipe for a dirty signal. A recent discussion on 
the Amps email reflector pointed to a tutorial by W8JI on the topic of 
how to tune an amplifier. http://www.w8ji.com/loading_amplifier.htm  He 
ought to know -- he's designed a lot of popular power amplifiers for 
companies in OH and MS.

One thing that Tom observes as a weakness of many rigs is that when run 
at less than full power their own internal ALC system causes them to put 
out a spike of full power, which overdrives the amp and generates trash. 
He recommends running the rig at full power, with a resistive attenuator 
between the rig and the amp.  This is NOT needed with a K3, because the 
K3 does not generate that power spike.  But Tom's tuning instructions 
ought to be recommended reading for anyone with a tunable power amp.

73, Jim K9YC