[Joeztech]

  The voltages are an important consideration, but you didn't mention anything about current ratings for this transformer. From your description it's a light to medium duty transformer even though it is inside a potted can. The typical radio power transformer has a high voltage winding somewhere between 300-0-300 and 350-0-350, 271-0-271 is rather low considering that this is with no load across the winding.
   I would guess that since this transformer has a proper 5 volt rectifier winding then the H.V winding is probably rated at 125 ma or something since the voltage is around 271 volts with no load. You could use a 5AR4 but it's probably over rated for this application, a 5Y3/5Y4/80 will handle it quite nicely. Just remember that whilst you may almost double the output voltage by using a silicon bridge rectifier and omitting the center tap you will also reduce the current output of the supply by half verses a conventional full wave setup.
Regards
Arran

Arran;

Yes the power transformer does have its limitations. There is also the voltage doubler approach using silicon diodes that could be used. There are even full wave voltage doubler topologies that can be employed if I need to go much higher. However, for most of what I want to work with the transformer should be adequate. I don't plan to be working with circuits that need large amounts of current or high voltages. This is just a way to use what I have on hand for now. Later on I might look for a transformer capable of higher voltages and current capacity. I still need to build the supply and test its load capacities. As you said the fact that it is potted does not necessarily mean it has enormous current capacity. TBD!

Joe