on that topic - i wonder why Duke went to 800 instead of re-farming their 900 stuff? Perhaps for interop? (aren't most all 900 p25 portables single band?)
900 MHz is a mess with the already limited spectrum being split up in order to create a 3 MHz block of broadband spectrum (936.5-939.5 MHz), leaving only a 1.5 MHz and 0.5 MHz portion of the band left for narrowband (935-936.5 and 939.5-940 MHz).
If you can acquire 800 MHz frequencies, then that is probably a better choice to a) avoid dealing with the 900 MHz reconfiguration, and b) to allow for the potential of interop with others operating on 700/800. In some jurisdictions, the utility companies are given access to the public safety trunked system, even if that's limited to supervisors being able to operate on the fire talkgroups or whatnot. Obviously if your radios are already capable of operating in the band, well it's that much easier.
And yes, 900 MHz subscribers are almost always single band. Some models geared towards public safety, like the APX 6x00/7x00/8x00 were never even given 900 MHz capability, you have to go down to the lower tier models for single band 900 MHz.
Oh and as far as the idea of linking P25 systems together, it really has nothing to do with the manufacturer or company building them out, and everything to do with the P25 ISSI (Inter-RF Subsystem Interface) standard.
