Actually a 12 volt 70 ma 2 1/4” would work….there is room for 3 1/2. I did get a 30 ma from my son but it does not push enough air….. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mailman.qth.net/pipermail/mcarc/attachments/20160115/e1ee34cf/attachment.html>