Question about Blonder Tongue modulators

[CPQ5360]

Thanks for the info. I see MAVM modulators for quite cheap, so I may grab one.
Thanks for the info on the channels. I'm still a little confused - I found charts online listing the different cable channels and their frequencies, and some list J as 525.25 MHz, the same frequency as UHF 23, and others list it as 217.25, which is just above VHF 13. O_o I just don't want to accidentally get a modulator that can't be picked up on a standard VHF/UHF TV set.