down here in the southwest, we're using a 4.20 mhz split it seems to be pretty common even the opc common channel uses it. Some examples are:
138.4800 in 142.500 out
138.2400 in 142.2600 out
138.750 in 142.770 out
If this doesn't work for you, running trunker program will give you the inputs, or being near a busy hospital, and searching 138 mhz to 144 mhz, the doctors and ambulance seem to have a lot of dialogue and its an easy catch.
Although many outputs in the 142-144MHz range have inputs down 4.02MHz,
there are many exceptions. It also depends on the site; outputs can be
paired with different inputs.
You could find them by listening to each output frequency at a time
on one scanner, while scanning the ranges 138-140 and 148-150MHz
with another scanner. I don't think there are any inputs in the 3rd range
used at this time.
The other way is for someone to run Trunker software on the site's
control channel. Version m3.8.3 displays input and output channel
numbers, which can then be correlated to actual frequencies/pairs.
You might expect 142.890 to be paired with 138.870, which it
was when it was a conventional MOH pair, but the input is now 149.830.
138.870 is (was) paired with 142.515 output, which is no longer
used on this site.
You might also expect 142.335 to have input 138.315, but its input
is 138.375; 138.315 is paired with 141.690. And so it goes.
Hydro-Quebec uses 142.395 which you might think goes with 138.375
(above), but Quebec and some other provinces typically use 3.99MHz
separation rather than 4.02MHz, and again there are lots of exceptions.