I found in my shelf these tubes...if anybody is interested make me an offer and i will check the filaments...I don't have a tube tester. National Union NX 245 4pin National Union NX 80 4pin Cunningham C 327 5pin RCA Radiotron UY 227 4pin Philco Triode 4pin All the best Martin 'Sandy' Sandberg N5NBW in Dallas Texas All the best Martin 'Sandy' Sandberg N5NBW in Dallas Texas