Yeah, when I owned/operated 220 repeaters (early 90s) 223.50 was the National FM simplex frequency, equivalent to 146.520 Mhz. I purchased several old 220 xtal rigs that had 223.50 simplex in channel 1. That said... a lot changed when we went from sharing 220-225 to being sole occupants of 222-225 Mhz. It could have changed, but I highly doubt it. And by the way, SO many people think that band change was some kind of tragedy, "we lost our frequencies!"... no, it wasn't and no, we didn't. They weren't OURS... we SHARED them with other services. The whole thing actually secured the upper 3 Mhz of the band (repeater segment) for us. Plus, once it was over & done, more manufacturers started producing new 222 rigs/HTs and even repeaters.
As for the MRC link... "222 Mhz (222-224 Mhz, sometimes called 1 1/4 meter band)
222.350 Mhz is the National FM simplex calling frequency. A 20 Khz spacing matrix is used on this band. Other frequencies in the 223.600 to 223.850 Mhz range are also used for FM simplex."
I see (what to me are) two typos and one questionable phrasing... I think whoever typed this up did not know for sure what they were typing. I might have thought they perhaps had to follow some kind of weird bandplan in Minnesota being on the border with Canada, but FM simplex in Canada is 223.49 to 223.59 according to wikipedia. - I would follow the SERA bandplan.
And you called is the "1.25 meter band (224 MHz)"... it's referred to as either the 220 or the 222 band... 224 is in the middle as it's 222-225 Mhz. I know because my repeaters were 224.90, 224.98 and a portable machine on 224.94; the last of which was a VERY popular repeater frequency waaay back and many old xtal rigs had that channel along with the 223.50 simplex.
And just to share... I think 222 is the BEST repeater band we have. It has about half of the 'bounce' (reflection) of 440 and roughly 90% of the range of 2m. I once demonstrated from inside a building... my 2m could not get out of the building. The 440 could hit a dual band repeater in a car in the parking lot but did not have enough "umph" to reach the regular high repeater in town. However, the 222 HT was full quieting to the repeater in town on a half watt; bounce and range. And don't get me started on how cool band openings were!!! Once worked a mobile in Georgia from north west Arkansas through a repeater in Kansas City... that was SO cool!
73! ENJOY! Kevin N4UFO