Bandwidth = 2 x (dev + max freq of mod)...so 2x (4.5+3) = 15 kHz B/W, so
4.5kHz dev COULD work on 15 kHz spacing if everything was perfect (DEAD on
freq, etc)....but this not a perfect world.....5 kHz dev will work in 20 kHz
spacing but not a 15 kHz world!

For 3 k dev, it's 2x 3+3 or 12 kHz.....again ok for 12.5 kHz if everything
was perfect...but the rcvrs probably arent filtered for that as well!
For 12.5 kHz spacing, the dev has to be lower like 2.5 kHz...but then your
audio will be lower in the normal 20khz spaced radios...

Chris
WB5ITT

"Leon" wrote in message
oups.com...
Does anyone know what the transmitter deviation should be for accessing
repeaters with 12.5 kHz channel spacing. I've got a feeling that it
should be +/- 3 kHz instead of the +/- 4.5 kHz used for 25 kHz spacing.

73, Leon