You are correct. 6A5G is indirectly heated. It has a cathode connected to pin #8. Basing is 6T.
You can find additional information here:
http://www.mif.pg.gda.pl/homepages/frank/sheets/121/6/6A5G.pdf
Data is not incorrect. You can look into the tube and see structure.
If you want to get those guys going mention 2A3H. It's also indirectly heated.
Norm
:Greetings- I have always been under the impression that the 6A5G (cousin of the 6B4G, 6A3 , 2A3, etc.) is an INDIRECTLY heated triode with a center tapped filament. Over on Audio Asylum, a somewhat heated debate is brewing in that a very knowledgeable inmate is claiming that the 6A5G is a DIRECTLY HEATED triode BUT, with a center tap. He goes on to say that he has known this for 30 plus years, and that Sylvania, the developers of this tube, even posted the incorrect data in the original Sylvania Tube Data Book. With the exception of breaking open and examining the plate/filament structure with a powerful magnifying device, is there any way to substantiate this claim using either a Hickock 533A and a Fluke 179 multi-meter? I'm not looking to "take sides" in this debate, just trying to clear up this anomaly. I beleive that Peerless made an amplifier that was designed specifically for this tube, has anyone seen the schematic? Thanks very much, Paul