Can I put two of these cheap (less than 3USD) and common CFU455IT +/-2kHz (4kHz bandwith -6dB ) ceramic filters in series to get a lower bandwidth good for SSB TX? If I'm correct I will get -12dB at +/-2kHz so the bandwidth will be reduced a bit, I can trim the rest by adding a trimmer in parallel to the filters and playing with the loading resistor. What about CFU455HT? They are even more easy to get and cost 1.25USD. It sure beats paying 50USD for a factory made one and I have only so much crystals to put in filters.

When making an SSB superhet RX are lightly loaded (100k ohms) LC resonant circuits and RC lowpass audio filters good on their own or do I really need that filter? filter datasheet

73 de SO9LEK


Putting multiple ceramic filters in series is common practice. There is additional loss; twice as many filters equals twice a much loss, may have to adjust the amplifier a bit.

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.