I just got a pair of 1956 Tung Sol 5998's flat plate tubes intended for my Crack. I noticed a few things right off the bat before trying them out:
*One of the tube base is loose and you can wiggle it left and right probably a millimeter either way. This does not seem to effect the working of the tube as it has a nice glow and the sound is phenomenal. The getter is nice and shiny indicating ( I believe ) a good vacuum still exists. Other than the obvious caution needed in handling (removing or inserting) this tube...should I be worried? Obviously, one without a loose base would have been much preferred...and I will be getting with the seller today to ask for a replacement, however, I wanted some knowledgeable input.
*both tubes appear to have a lot of debris...or dust on the inside of the glass. I have a lot of old NOS tubes...and these are the first I have ever noticed that have debris on the inside. I can't get any of it to bounce about...and it seems to be stuck to the glass. I don't see anything on the plate or other tube mechanism. How the hell is there anything inside the glass? I suppose the debris / dust is on the outside...however, I can't feel it by touch and it doesn't wipe off.
Both tubes are beautiful Tung-Sol 5998 flat plate vacuum tubes...I'm very happy with the sound. I don't have any more crackling or popping while warming up (about the first 3 to 5 minutes)...
Anyway...hope to hear back from some of you knowledgable folks with some input. Honestly, if there's nothing to worry about...just let me know. I'm a bit anal with stuff like this and I have to tell myself to back off sometimes.
Regards,
Ken