XTL mobiles - differences between 1500 2500 5000?

[Thunderknight]

What is the difference between the XTL1500, 2500 and 5000 mobiles?
For example, I see the 1500 has a control head with a smaller display and a large knob. Is that the only 1500 head? I know the 5000 supports a variety of heads...does the 2500?
Is the 1500 limited in the channel capacity?
Is the 1500 capable of encryption or is that in the 2500 and 5000 only?

I am looking to update my VHF and UHF CDM base radios to XTL to get P25 conventional. I don't need encryption, but I don't want to be limited to a small number of channels (my CDMs are 64 channel and that is a bit limiting). The price differences on eBay between a 1500 and a 5000 can be large, so I don't see spending the extra for a 5000 if I don't need it.
How limiting is the smaller head on the 1500?

(These would be front mounts used in a desktop situation)

Thanks

 

[N4KVE]

Except for control head features, the radios are electronically the same. The higher the model number, the more features in the radio. I once bought a 5000, that actually started life as a 1500, but it had a 5000 head, & all the features of a 5000.

 

[MTS2000des]

The 1500 has a small LCD display, 2500/5000s accommodate a much wider variety of control heads (O5/M5/O3) and more display real estate for zone names/channel names. The 1500 does have an internal speaker, something not found on higher tier XTL radios. But as Gary said, the internals of the actual radio are the same. It's all in the software loaded at the factory and the associated control head. FWIW the 1500 control head only works on XTL1500/PM1500 radios and won't function in any other configuration.