[Elecraft] K3 Enhancements and Application Notes Page (CW rise time)

[Bill W4ZV]

michael taylor-3 wrote:
> 
> 
> I thought it is meant to be read, any K3 _up to_ S/N 211 may need the
> modification. I take it that after that point in time a change was
> made. Or am I just reading things backwards? Similar to how a number
> of modifications were available/needed for early model K2s whereas a
> late model K2 had very few mods / re-work needed.
> 

Correct...units prior to ~211 will need it and afterwards will not.  If
yours is near 211 (+/-), you may need to check the capacitance of C222 using
a capacitance meter.  It should read ~0.1 uF (or ~100 pF) if the mod has
been installed (if not it will read ~1 uF).

I'm guessing on this, and hopefully Eric or Wayne should confirm, but I
would expect that both the HAGC and keying mods were implemented in
production at the same time, since the S/N transition is the same for both
(i.e. ~211).  If this is true, you can easily determine if your unit was
modified by looking for a discrete 1.8k resistor installed between C196 and
C197 as shown in the HAGC mod instructions.  If that resistor is in place,
it's a good bet that C222 has been replaced as well, but a capacitance meter
will tell for sure.

73,  Bill  W4ZV
-- 
View this message in context: http://www.nabble.com/K3-Enhancements-and-Application-Notes-Page-tp16343769p16369716.html
Sent from the Elecraft mailing list archive at Nabble.com.