Some weeks back, we published our designs for building reproducible TX-BPF filters easily.
10m TX-BPF:
Results of the PCB build:
While many amateur radio operators focus solely on antenna optimization, the significant benefits of TX-BPF filters are often overlooked or under-discussed in the hobby! Even with HOA antenna restrictions, you can still optimize your station's performance through proper TX-BPF filtering.
We have reduced the cost of such filters by using cost-effective 1kV SMD C0G caps instead of hard-to-get and "probably-obsolete" Silver Mica caps.
Cost: Less than 500 INR per filter!
Time to build: Less than 30 minutes per filter
Tested input power: 15W. They should go up to 25 to 30W.
The files for this project are published here for personal (non-commercial) usage.
Learning: Elsie works much better (produces realistic filters, enables interactive debugging) than Qucs Studio and Marki Microwave Filter Design Tool. While we are not fans of proprietary software, we are forced to recommend Elsie - it is that good!
Special thanks goes to VU2SPF for all his help!