For anyone planning some winter nights working on an SP-600, check out: eBay item number: 163887526843 Cheers, Doug W5JV Visit https://www.qrz.com/db/W5JV for some great vacuum tube finds. Looking for something special? Ask us. Wanted: Petersen Type PR-1 in FT-243 holder cut for 1770 kHZ (Used in IF Stage of a Mackay Receiver).