This circuit is for the ME40+
Since the SW+ series kits were introduced in the late 1990's a new compliance specification from the FCC came out in 2005 stipulating the 2nd order harmonic has to be at least 44 db down from carrier. The ME+ series CW kits were designed to mimic the exact SW+ series kits. So in order to satisfy the new compliance, a series tuned filter on the output of the ME+ series units correct the problem. All future kits for all bands will have the parts to fix this problem upon request. It consists of a series LC circuit made up with a toroid and capacitor along with a load resistor to notch the 2nd order harmonic.
This circuit is for the ME40+
Also a capacitor has been added to the keying line to lengthen the fall time of the carrier thus reducing any off channel clicks. This capacitor will be in the new kits and sent to you with the tuned notch filter circuit. This capacitor should be soldered on the bottom of the circuitboard.
A small circuitboard is now available and can be soldered on the BNC connector that contains the toroid, capacitor and resistor. This mod is available for $5.00 postage paid.
Of course a good antenna tuner will remove more of the 2nd order harmonic too.