[Elecraft] strange keyer problem (#5670)

[Don Wilhelm]

Kirk,

You may have accidently gotten something sticky onto the keyer plug tip 
which is now stuck inside the jack and making the contact resistance too 
high - since you can insert dits, I suspect that increased resistance 
somewhere in the dot circuit line is the most likely problem.  Make some 
more continuity checks to confirm where the problem is.

You can easily remove the left side panel to gain access to the 220 ohm 
resistors (R1 and R2) in the dot and dash paddle lines and allow you to 
check continuity from the paddle terminals to the inside of the K2.  The 
resistors are located on the edge of the RF board near the key jack.  If 
you find good continuity between the paddles and the resistors R1 and 
R2, then the path through the jack is fine - check continuity to the 
microprocessor pins (Control Board U6 pins 29 and 30) for the other half 
of the path.

If there is no problem with the keyer jack or the plug to jack 
connection, try re-seating the microprocessor in its socket - that will 
clean the socket to pin connections which may help.

73,
Don W3FPR

Kirk Brown wrote:
> When I switched from straight key to my paddles, I found one side of the
> paddles would not work (in my case the dits). I checked the continuity of
> the paddles-to-plug and that's ok. I suspect the jack itself, but here's the
> strange part: I can make characters with dot insertion (G, Q, 9, etc.) but
> not characters that start with dots (E, 4, V, etc.). The reverse is true if
> I change from left to nor in the software. If I invert the paddle polarity,
> the opposite is true (dits and no dahs unless inserting). Any ideas?
>
>