My first commercial rig was an ARC-5. I had no plate meters and depended upon the blue in the 1625 tubes to tune to resonance. Last thing I wanted was a tube that was not blue. 73, Colin K7FM --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.783 / Virus Database: 529 - Release Date: 10/25/04