I have an old Atwater Kent 145 which runs from 110V.
I am thinking about converting it to 240V by replacing the mains transformer rather than running it from a step down.
The radio would never be returned to the US so I think by doing this I would make the radio more collectable in Oz.

In good condition this Tombstone model in the US is worth a few bob.

What would you do?
Cheers,
Gary

This radio came in a 110/220 version as well as 110V only. Are you sure yours is not the dual voltage model? If it is, my preference is to leave it as original as possible, meaning don't change the transformer.
I recently restored a 6V vibrator Airzone which would have been a candidate to convert to 240V, however I preferred to keep it as designed and made a 6V power supply, external to the radio, so it remained as intended.
Harold

I too would keep it 110v and use a transformer.
Ben

I also would use a step-down transformer - apart from originality in the radio you would have a step-down that you might find other uses for.

I'd keep it as is too. Resale value to someone who wants to run the receiver may go higher but there is no guarantee of this. Resale value would be highest if a stepdown transformer was included with the radio if it was sold. The value of almost any valve radio is highest when in the condition it left the factory in.

I have a number of US made intercoms. I intend to install small (50 VA) step downs inside them and leave the rest of the original power supply intact. I have done similar with my B&K valve tester.

Adopting this approach means the gear can be reverted to 120 volt operation easily, if desired, and meanwhile I avoid the external transformer.

However, of course, this is only practicable if there is room inside for an additional trannny.

Ok, thanks for you input.
I'll leave it 110V

Albeit they are not easily found here, also keep a 110V plug on it so that it is incompatible with ours, thereby reducing the risk of it getting blown up.

Here it is after restoration. I left it as 110V.