Mercury ref tubes of all types have mercury that sticks to the glass and components inside. Depending on the brand, type and year made the mercury deposits very a great deal. This is not a bad thing. If the tube has not been used for a while or has been stored on its side, it is best to COOK THEM FOR A FEW HOURS BEFORE APPLYING PLATE VOLTAGE. The 3B28 is a newer style and a better ref tube; it also has mercury in it but less. If you need any more info be glad to help. I have several patents in mercury vapor designs Brad KB7FQR
those flakes in your 866s are mecury. if they haven't been run in a while you should let them sit with just the filaments on for a while, to make sure the stuff gets where it needs to be. They look nice, but the mercury vapor rectifiers need to be treated well especially after a long idle period. You can direct sub a 3B28 argon rectifier tube, and not have to worry about the 866s. They don't glow as much, but are more tolerant tubes. ______________________________________________________________ ______________________________________________________________ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
