There's a very good article on tubes v. solid state for RF power in the IEEE Spectrum magazine for April. 73 Peter G3RZP -- FAQ on WWW: http://www.contesting.com/ampfaq.html Submissions: amps@contesting.com Administrative requests: amps-REQUEST@contesting.com Problems: owner-amps@contesting.com Search: http://www.contesting.com/km9p/search.htm