yes...dish tv tru hd is the device to do so...they have many such channels on their platform which is in SD, but they call that those channels are in HD...example Zee Classic HD, Utv Movies HD, MTV HD, Times Now HD...these channels are available in sd from broadcaster's end but dish tv is the only dth which claims it to be available in HD...
However, as a fact of the matter, no converter can covert SD channels into HD, otherwise there would not have been two channels running from broadcaster's end like sony and sony hd, zee tv and zee tv hd etc