While the four-channel filter-combiner is a practical accessory for the Beacon Blaster 6, it is becoming obvious that another filter-combiner will be useful. The 4-channel unit uses standard surface-mount inductors, and the inductor Q and current specs mean that for low-loss the filters need to be fairly wide, spaced at least one octave apart.

But if you have an antenna capable of working on more bands (such as the Hy-Gain AV-680), a combiner with more channels would be nice. So, here is the Seven-Band Filter-Combiner:

This design uses custom-wound toroid core inductors, which allows much narrower low-loss filters. The board is designed to allow the inclusion of a third-harmonic notch for each channel, but the narrower filter bandwidth provides better than -40dB attenuation of all harmonics so the notch will likely not be needed.

Here is the 10 MHz filter with and without the notch:

This plot shows the 7-band filter response without the notch:

This board has been sent out for fab and assembly, once it shows up I will wind and solder the toroids (and connectors), and find out of reality matches my simulations. My track record in this regard has been pretty good, so I am optimistic.

This will be a more expensive filter than the 4-channel one — hand-wound toroids are quite labor-intensive. But if it eliminates the need for a second antenna…