Robert,
Yes, those two mods are old, and apply only to the A level boards (below
SN 3000).
There have been improvements in the K2 sidetone incorporated into the B
level boards, and are also included with the A to B mod kit.
The changes added a 47k resistor in series with C24 (R11 for the B level
boards) and a shielded 82mH inductor across pins 7 and 10 of RP5.
The sidetone is still not a pure sine wave, but it is close if your
sidetone pitch is between 500 and 700 Hz.
Those old mods would be applicable to unmodified A level boards but
re-design of the circuits would be required for the B level boards and A
level boards already modified with the A to B upgrade kit.
73,
Don W3FPR
On 3/22/2016 5:52 PM, Robert G Strickland wrote:
The dates of the two sites mentioned are pretty old. I imagine that
any such mods or similar changes were incorporated in later K2's. Is
this the case?
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[email protected]
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [email protected]
