For Sale: For your 600L linear several NOS 813 Power Tubes. Five (5) to sell; reboxed because original paper was unusable. Filament continuity checked. $75 each shipped to upper 48 only via USPS Ground trac. QSL W5JV for ordering. 73, Doug W5JV Visit https://www.qrz.com/db/W5JV for some great vacuum tube finds.