Do a very close and careful check of the filament pins on the tube. The tube sockets used were notorious for relaxing the friction connection on the pins; the higher resistance created heat and the solder of the pins flowed out. The fix is to resolder the pins Careful not to overheat
David Assaf, III W5XU -----Original Message----- From: drakelist-boun...@zerobeat.net [mailto:drakelist-boun...@zerobeat.net] On Behalf Of richard radke Sent: Monday, January 02, 2012 6:31 PM To: drakelist@zerobeat.net Subject: [Drakelist] L4B Oddity I have an unusual situation underway in my L4B. Evan, you out there? Been working fine until yesterday (i know, well happy new year) one of the 3-400's filaments is half as bright as the other. I reversed the tubes and the same tube was dimmer in the opposite "hole", and the amp and supply seems like they're running hotter than normal. HV is normal, but haven't keyed it yet or applied drive. Pwr supply was rebuilt a couple years ago with one of Mike's boards. Has anyone seen a tube fail like this? Being a week after xmas and the YL's birthday Friday, not real anxious to spend 5 big ones on a pair of 3-500's right now, but a guys gotta do what a guys gotta do. 2nd question. I've got one 3-500 spare that I believe to be good. Has anyone ever mixed a 3-400 and a 3-500 in the same amp? Only for testing purposes. Just asking. Rick W9WS _______________________________________________ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ----- No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.1901 / Virus Database: 2109/4719 - Release Date: 01/02/12 _______________________________________________ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
