http://www.skyrocket.de/space/index_frame.htm?http://www.skyrocket.de/space/doc_sdat/echostar-11.htm
The 1300, a powerful, space-proven platform for a wide range of services, has been in constant evolutionary development to deliver increasingly greater power, communications capability, and longer useful life, keeping the company in the forefront of satellite technology.
Total satellite power ranges from 5 to 12 kW continuously throughout the life of the spacecraft. On-board transmitter power — exceeding 5,000 RF watts — can accommodate as many as 70 active transponders. Launch mass tops out at approximately 5,500 kg. Standard satellites in the 1300 line will fit into a 4-meter launch-vehicle fairing.
The size and capabilities of the 1300 can be expanded to generate and process more power, and accommodate larger, more powerful payloads. In total, these changes can provide up to 40 percent more capacity than available in the basic model, ideal for any of today's demanding multi-band and spot-beam payloads. The expanded models feature total satellite power that ranges from 12 to 18 kW throughout the life of the spacecraft, and on-board transmitter power — approaching 10,000 RF watts — that can accommodate as many as 90 active transponders. Launch mass of the largest version tops out at approximately 6,700 kg. This version was earlier called 1300S.
With all of their features and power, satellites in the 1300 line will fit into a 5-meter launch-vehicle fairing.
Loral does not use (anymore?) the sometimes reported designators for sub-versions like 1300E, 1300HL, 1300S, 1300X