I use a Bachmann power pack from their train sets, works fine
Harold
"Keeping my hand on the throttle...and my eyes on rail."
Any power supply that puts out the required voltage at the recommended mA or HIGHER will be fine; i.e., if you can get an 800mA or even 1 Amp power supply that will be okay to use. The device you're powering won't be harmed by a supply with a higher mA rating, but a higher voltage could harm it, and it won't function properly on a supply with a lower mA output.
All Electronics in Van Nuys, California, has a 15VDC 1 Amp power supply (PS-151) priced at $8.75 plus shipping. Two other possible mail order sources are Jameco Electronics and Mouser Electronics, but shipping is likely to cost more than the basic power supply.
I recently asked our forum experts to resolve the programming issues I was having with my Bachmann 4-4-0s and the MRC Prodigy Advanced. On this forum, and the Bachmann one, it was suggested that I purchase a programming booster. Following that sound advice, I bought the Soundtraxx PTB-100. In reviewing the installation directions, it mentioned using a dedicated power supply rated at 15vDC, 500mA. That is when my problems began...I cannot find a power supply with those ratings. I have found 15vDC, 400mA or 15vDC, 800mA - but not the one required.
My questions is: Where does one find such a power supply? I have done a Google search to no avail, as well as checking with Radio Shack (no luck). My last option is to drive into Huntsville, AL and try to find an electronics supplier (hopefully NASA uses some of these power supplies). Any suggestions? A supplier told me that the 15vDC, 800mA model would work just fine. An electronically knowledgeable neighbor said electronic circuits are very fussy and I should only use what the manufacturer suggested. HELP!