I do have the following signals in my area:175 kHz that appears most every day after dark. There was a month or so it disappeared this year but was strong during the winter.
228.1 and 228.6 seem to be companion signals. I seem them most every day after dark.
I have three that may be NDB's. I say that because I can find listings for these frequencies in the data base. They are 215 (no Morse Code marker), 230 and 233. Both have no ID.