Am I programming this right...

[Renamon]

I've been doing it this way for about 6 years now, just want to make sure I'm doing it right.

If I am programming a NARROWBAND (ex 142.5625) VHF IMBE SIMPLEX channel, it should be:
2.5 deviation, 12.5 width, C4FM (NOT CQPSK/WIDE).

If I am programming a WIDEBAND (ex 142.565) VHF IMBE SIMPLEX channel, it should be:
5.0 deviation, 25 width, C4FM (NOT CQPSK/WIDE).

If I am programming a WIDEBAND (ex 142.565) VHF ANALOG SIMPLEX channel, it should be:
5.0 deviation, 25 width.

I have never had anybody tell me how to program my equip, just what I've read and experimentation...

[Josh]

Looks right to me.

[dxon2m]

Correct me if I'm wrong but I thought all IMBE C4FM signals are 12.5khz wide?

[MattSR]

Correct me if I'm wrong but I thought all IMBE C4FM signals are 12.5khz wide?

Bingo! You are correct. The deviation and channel width settings are ignored in P25 mode - they're only there for mixed mode and channel spacing.

Deviation in P25 is fixed by a combination of the symbol points (-/+1800hz and -/+600hz) and the nyquist filters used. So yeah, it doesn't really matter

[escomm]

Correct me if I'm wrong but I thought all IMBE C4FM signals are 12.5khz wide?

Bingo! You are correct. The deviation and channel width settings are ignored in P25 mode - they're only there for mixed mode and channel spacing.

Deviation in P25 is fixed by a combination of the symbol points (-/+1800hz and -/+600hz) and the nyquist filters used. So yeah, it doesn't really matter

And yet just about every LEA here in LA using P25 (hello LAPD) has 25KHz channels, and keep their compliance by throwing the CWID every 15 minutes in wideband analog... So much for spectral efficiency

[MattSR]

lol nice!

Meanwhile Motorola is pushing the P25 phase 2 (6.25khz) technology, and the FCC is mandating that everyone switch to narrowband in the future.

what a joke!