Your ears will be the only filter that you need!
This will be the first winter event of this type and results could be very interesting! In the past, many participants have used their homebrew regens including the popular ‘1AD’ (1 Active Device) MOSFET regen, built for the NDB part of the spectrum.
The last time this event occurred, I whipped together a 1AD regen in a day which proved amazingly effective in spite of the mid-summer propagation.
There is still plenty of time for you to put something simple together and you can find some helpful suggestions in my previous '1AD' blog here.
I will have more details later, before the event, so please stay tuned and consider getting something ready ... maybe all you need to do is wind a new coil for your favorite regenerative receiver!