I've started a restoration on my Kriesler Duplex (model 11-41) and, of course, the very valve that's blown (cracked actually) is the hard to find 6M5.

I note the various recommendations for substitutes, including 6BQ5 and 6BM8, and also 6GW8, but I'd like to exhaust my avenues for finding a 6M5 (or its equivalent EL80) before going the modification route.

Talk about bad timing: Googling around I note that I missed some 6M5s on eBay about a week ago.

So, is there anybody out there who is willing to sell me an operational 6M5 / EL80?

*** Update 29/4: I have sourced a few 6M5s.

-- CLOSED --

There is an article in Silicon Chip which comments on 6M5 problems. While yours is cracked so this does not apply, it might apply to any "dud" 6M5s that you might come accross.

http://www.siliconchip.com.au/cms/A_30811/article.html.


"...I scratched between pins 1 & 2 of the 6M5 with a screwdriver so that any silver migration between grid and screen would be disrupted. This prevents positive voltage being applied to the grid. It might sound like a strange thing to do but 6M5s have been known to have silver migration between these pins, which means that the valves are often (needlessly) thrown out because they are thought to be "gassy"."

I still have a few NOS (new old stock) 6M5 tubes on hand if you are interested. Andrew -- thermion45gmail.com