Isolation Transformer and Subpanel recommendations

Quick search on Ebay turned up empty for this size and 120V. Generally prefer iron core instead of wide-band toroidal for this purpose. If it's going to be close to the rest of the system, toroidal has the benefits of less stray EM and more convenient packaging. Without step-down....

http://www.surplussales.com/transformers/IsolationXmers-3.html

Although, if you can get 240V there, options get much wider and less expensive. Perhaps even the option of center-tapping, if derated by half.

Thank you for the help and pointer; we can get 240V here up to the house but given it's US, it has to be broken into 2 120V phases inside the house. I'll check out the link you sent.....thanks!

we can get 240V here up to the house but given it's US, it has to be broken into 2 120V phases inside the house.

"it has to be broken into 2 120V phases inside the house."

Would you care to expand?

Noise is unpredictable for either type, aggrevated by external conditions. Potential advantage of tighter windings of toroidal is offset by greater sensitivity to same conditions. Some people mount the transformer near the electrical panel (basement?), away from the living space.

Dryers and ovens are usually 240V.

Jea48: the wiring in our houses here is 120V and 240 comes into the house and is split out normally. I did have an error in my response in that we are not obligated to only have 120V here. I currently have a 240V line to the kitchen where an old electric stove used to be, another for a heat pump, and a 3rd for the dryer to the laundry room. I could choose to run a 240V line to the attic for an isolation transformer if I had to. For that matter, I could also choose to drop an entire 2nd house circuit immediately after the meter and skip the main breaker panel altogether; my response was more thinking of limiting the invasive electric/structure work that would be required here. My apologies for the confusion my original response probably caused...