ever recently in our crazy tech epoch it is not everyone has a
Spectrum Analyzer in own home or access to such device at some
place. Without a Spectrum Analyzer it is possible to tune the
Low Pass Filter for 145- MHz Band to minimum SWR but
hard to adjust the internal rejection filters. In this case it
is possible to do a compromise variant of such filter-without
internal rejection filters.
Schematic of a simple Low Pass Filter for
145- MHz Band without internal rejection filters is shown in Figure 8.
filter made on a piece of two sided PCB. Capacitors of the filter
are created on the board. Figure 9 shows
design of the filter. Figure 10 shows
view of the filter. Figure 11 shows
layout of the capacitors. The capacitors made on a PCB that has
thickness in 1.5- mm. However different PCBs depend on the stuff
and the thickness may have another capacity per square centimeter.
It is very useful to find the capacity per square centimeter and
re-calculate (if it should be done) the sizes of the capacitors
before the capacitors would be made.