Posted by
Mike Scott-7 on
Oct 24, 2010; 6:22pm
URL: http://elecraft.85.s1.nabble.com/K3-Sub-RF-gain-tp5659334p5668291.html
Joe (W4TV)
Yes I have performed the gain calibration many times on both receivers using
the K3 Utility with the XG2. I recently did it after loading the new K3
Utility that supposedly fixed some issue about writing receiver gains to
memory. So now you make two people whose RF gain tracks.
I can't begin to speculate anymore as to the difference in RF gain behavior
in the two receivers. So to repeat: same antenna (to XG2), same stock
filters with matched offset, same (0) filter gain, same ATT on, same PRE
off, same IF filter width, same NB off, same NR off. Sub Rx gain set to
minimum I can still copy signals and hear band noise, Main Rx RF gain set to
minimum is dead band.
This difference in RF-gain tracking makes it difficult to use reduction in
RF gain as a method to manage high band noise conditions. I can't just grab
both controls and move them the same, like I can with AF controls which
track very well.
Stan KR7R Main Rx RF gain behavior is bizarre. In the days of old
potentiometers this would be explainable but not with gain controlled by
firmware. Maybe a bad RF gain control with odd switch bounce behavior at
some gain setting... I would try to move the RF gain knob while K3 is shut
down to a new position and then turn it back on to see if the RF gain
nonlinearity location changed to someplace other than 9 o'clock.
AE6WA
Mike Scott
Tarzana, CA
>>Joe W4TV said.
Both of mine operate as expected (same RF/AF gain response for main
and KRX3). Have you performed the RF Gain calibration on both of
the receivers using a calibrated 50 uV signal source (e.g., XG-2)?
______________________________________________________________
Elecraft mailing list
Home:
http://mailman.qth.net/mailman/listinfo/elecraftHelp:
http://mailman.qth.net/mmfaq.htmPost: mailto:
[hidden email]
This list hosted by:
http://www.qsl.netPlease help support this email list:
http://www.qsl.net/donate.html