What a great reflector. Tnx to all with your comments. I have enough info now. I guess I'll go with the air variables to start, only have 100w on 160 at this time, and upgrade to the vacuum variables when I can find them (eBay is one source) and when I'm QRO. I also plan to go with the non-metallic enclosure. Tnx agn to all and cu on Topband, eventually. Phil KB9CRY