Was doing a bit of reading to confirm the frequency range for 15 meters to think through the IF article in this months AR magazine. So 15 meters covers; 21.000 - 21.450 MHz. I have a hand full of 4MHz and 25MHz crystals.
While I was reading through the band plan, I found something new, and entry for 2200 meters. But what grabbed my attention even more was that there was a mention of QRSS;
137.6 - 137.8 kHz Slow CW modes, e.g. QRSS