[TCML] Choosing secondary coil form size

[Michael Bellah]

Hello list,
              I have decided to build my first coil and have sourced a NST from a local sign shop. Its rated output at 115v is 9kva/120ma. I was planning on using a secondary coil form around 4x24, but I was also planning on a smaller transformer. I am wondering if I should go to perhaps 6 or even 8 inch diameter due to the 120ma out of the transformer or is this a wash because it is only 9kva out? Thank you in advance for your help.

Michael Bellah