The co-ordinator for that block of channels without checking with NYPD licensed a police agency across the river from NYC with the exact opposite pair of channels, and on top of it the same PL. So any unit that transmitted set off a feedback loop that lasted until the repeater timed out.
At the time I was working for a contractor that was installing new equipment for NYCTA which got those NYPD pairs. It took years and some litigation to fix it, but basically NYC said it's not our problem you fix it since we have been licensed on them since the 50's.
There were some changes along the years as people who did coordination retired or died. It used to be very common for neighboring jurisdictions to be lumped onto the same frequencies, especially on the fire frequencies. Sometimes it worked out okay, because there was mutual aid, but it went very bad when towns changed PLs and some even took simplex channels and made them into repeaters, each with independent dispatching.
More recently, all of the coordinators are
supposed to be using the same methodologies for picking and protecting frequencies, but mixing digital and analog has complicated the process, and narrowbanding didn't free up anything because they halved 15 kHz channels to 7.5 with overlap into the adjacents instead of going to 6.25 and 12.5 kHz spacing that would have had no overlaps. In NYC and NJ, those resources are scarce. That's why the big systems like NJ's NJICS are so popular, because they're the only way to get communication if you are a new agency or have outgrown your old capabilities.
The coordinators don't assign PL or paging tones (thank goodness!). Those are picked, usually by the manufacturer or local radio shop. I used to be the guy at my shop who kept a big typewritten list of frequencies and tones, like the database here, but back in the 80s and early 90s. There are so many places now that don't know the business, or they're mail order (really they're wide-area Internet businesses, but mail order sounds worse), and they won't even look in the database here to see what's what. They just plop someone down and there they are.
A while back, some people in the industry wanted the FCC to record CTCSS/CDCSS/NAC/color codes/etc. and they wanted Industry Canada TAFL style records of receiver sites, including what frequency is paired with what other in repeaters. The FCC didn't have anything against it, they started the CLS initiative (consolidated licensing service) to replace ULS and the little baby databases kept by the other bureaus, but funding ran out and the people who were managing the project are more than likely retired or dead (some, both) by now. Anytime ULS needs to be modified, they have to find funding, first, then have someone code a patch. So, recording those things so you can see an official record just wasn't in the cards. But the database guys here do it all the time and it looks more user-friendly than ULS. Go figure.
