DL2NBU presents complete design of W3NQN type BPF at BCC pages.
ICE filters have poor attenuation of higher bands. Only 11 dB in 28/21 MHz
set.
Dunestar is better as it uses center tap on the coil providing some 30 dB
isolation.
Bear in mind that close coupled anteenas may provide only 20 dB isolation.
All you need for SO2R or M/S is the set of 6 BPF shared for RX protection
but nobody offers that.
High voltage capacitors are required for 100/200 W TX BPF models making them
expensive.
73 de Mario, S56A, N1YU
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