K1EL
Morse Code Practice Oscillator
CPO
CPO Datasheet – A.3
4/10/2020
Page
7
Install the two pushbutton switches, insure that the black switch goes in location S1 and the
red switch goes in location S2. Insure these are fully seated into the board before soldering.
It works best if you hold the switch in place while you solder one of the leads.
Install three electrolytic capacitors at C6, C9, and C11. Note that the plus side pad on the
board is square and this is where the longer of the two leads will go. As a double check,
note that the black band on the capacitor is oriented opposite of the + sign.
Install the two 20K control pots, RX1 and RX3. Be sure that these are fully seated to the
board before soldering. If you don’t do this right, the board won’t fit the enclosure. Also make
sure that all three signal leads go into their correct holes. If you push the pot firmly in place,
it will stay there while you solder.
Figure 5 – Second stage assembly complete
Now install three surface mount 1/8” jacks. Don’t let the term ‘surface mount’ scare you,
these are very easy to install. The light colored jack goes in the middle at location J2. There
are pilot holes in the board that accept the plastic nubs on each connector. Once in place
simply apply heat to the connector’s solder tab and the PCB pad and then flow some solder
over the tab. To insure mechanical strength, be sure to use enough solder to just cover the
tab but not more than that. Use Figure 6 as a guide. Keep in mind that these are plastic
connectors and can be damaged if you use too much heat or touch them with your iron.