Batboard

Anyone know what is required for an AS or XTS to do CQPSK in conventional mode?

Setting my current radios to CQPSK results in them still transmitting C4FM.

Is a special firmware upgrade/version required?

Is CQPSK only used on Project25 9600 systems with the LSM option? Any conventional operation available?

Hmmm, the RSS help says that the radio just needs to be equipped with CAI, so 9600bps shouldn't be necessary. There have been several posts here in the past where the radio had been set to CQPSK and it definitely wouldn't talk to other Astro radios which were set to C4FM. I've never messed with it, so I have no other info. Perhaps it only works if you set it to narrow-band operation? The help indicates that's what CQPSK is supposed to be used for (well, in narrowband simulcast systems, anyway).

Todd

How do you know your radio is still doing C4FM - are you looking at it on a spectrum analyzer?

Remember - a C4FM receiver will still demoduate a CQPSK signal - that is after all what the C stands for - "Compatible" as in "compatible with C4FM".

Re: Is CQPSK only used on Project25 9600 systems with the LSM option? Any conventional operation available?... That was really interesting and, for me, it raised a few questions about using CQPSK on ASTRO25 systems:
1) is this modulation actually Project25-compliant or has it got something proprietary (like M.'s 'Wide Pulse' which adds M's own Tx filtering to C4FM)?? Is it the vanilla CQPSK that fits into 6.25 kHz channels??
2) can you use CQPSK on ASTRO25 trunked digital simulcast 3600 systems?
2) what is the main advantage of using CQPSK for simulcast modulation as opposed to plain vanilla C4FM or Wide Pulse. Is it the spacing/distance between Quantar sites?
3) I know CQPSK will replace Wide Pulse/C4FM when 6.25 kHz channelization happens. But will this happen for 12.5 kHz channels too?

LSM is P-25 compliant.
Motorola currently offers LSM on P-25 trunked systems at 700 and 800 MHz.
You're correct. The main advantage of LSM is that it is a P-25 compliant waveform (12.5 kHz CAI signal) and that it allows improved site separation over narrow-pulse (C4FM) simulcast. (ANP ~7mi, LSM ~14mi, AWP ~21mi).