ZachTek WSPR TX Mini Build Instruction page 4

Checking out the placement on the circuit board.
If you check the printed text on the circuit board you will find the positions for the capacitors -
C4 is not printed
due to an error in the manufacturing.
There are two capacitance values in the filter.
C1 and C4 are smaller in value than C2and C3. The exact value depends on the frequency band the filter is
made for.
To find the value check the "SMD low pass filter table" in the appendix.
As an example for a 20m filter C1 & C4 are 180pico Farad and C2 & C3 are 390pcio Farad.
As a memory guide to aid in placing the correct values, think – Higher value capacitors in the center
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