There is some mis-information in this thread that I will attempt to clear up. Just about all transmitter manufacturers today are using switching power supplies by a third party. The original question was about NV7.5LT and several of the answers were about different models , and different power supplies entirely. For current product, the NV-LT and GV series, they both use the same GE-Lineage power supplies, Nautel part number UG-92(x). These are Platinum class power supplies, the latest generation with high efficiency (lower heat generation) and very low MTBF. With Nautel's 4-year warranty, the vast majority of these are still under warranty. The NV Series and VS series, used the UG69(x) series originally made by Tectrol, now made by CUI (the company that bought Tectrol). New replacement UG69 power supplies have been re-designed and are now also Platinum Class supplies. CUI will repair the old supplies for about $150 each, but you have to deal direct with CUI, these repairs do not go through Nautel. It is true that you should not mix new and old UG69 supplies, but that is only true for VS, not true for NV.
There are still other power supplies if you are talking about the V Series (2008 and earlier-UG39), or if you are talking about low voltage supplies in the VS and NV (generally made by Meanwell). Of course the lower the cost of replacing the supply, the less sense it makes to have it repaired. Switched mode power supplies in general, within the electronics and communicatons industry as a whole , are regarded as throw away/disposable, so when you find someone willing to repair them, at any cost, it is a bonus.