For several months I've gotten hints from multiple companies that new, much higher efficiency. UHF solid state TV transmitters were coming soon. It looks like "soon" may be IBC 2011, starting Sept. 8 in Amsterdam.
I didn't see any transmission topics listed in the IBC 2011 Conference Programme, but a recent release from Thomson Broadcast on DigitalTVEurope.net and other websites says its Futhura Plus transmitter offers transmitter efficiency as high as 35 percent. This is comparable in efficiency to the IOT (Inductive Output Tube) amplifiers used by many broadcasters today for high power transmitters. Thomson notes this efficiency is a 50 percent improvement over current standard solid-state transmitters on the market. There is no detail on how this efficiency improvement is achieved, other than the statement that the Futhura Plus transmitter features "drain modulation technology."
If the price is right, this technology could be a good replacement for the many single and two tube IOT transmitters that have been in service for the last 10 years or more. It seems unlikely that even with these improvements solid state transmitters will be able to replace higher power, higher efficiency MSDC transmitters, at least for a while.
As soon as I have more information I'll post it in RF Report with a more detailed description in my RF Technology column in TV Technology magazine.
2012 NAB: Solid State Transmitters Now Match or Exceed IOT Efficiency
With improvements in solid state transmitter efficiency, it is now practical to use two combined 10 kW range solid state transmitters instead of an IOT.