[Adam]

I'm still immersed in my B&W Hoffman now, but I pulled the tubes on this to go test them last week. I have a B&K 500 and a TV 11, but these are both too old to test all these tubes in these color sets, so when I was driving up north I took them all with me to a store up in Berkeley that still has a B&K 707 in use. I also went and copied the sams from the public library up there.

What I noticed about this TV when I was removing the tubes, that is odd, is that the UHF tuner is not the same one listed on either the tube diagram glued to the HV cage or in the sams. The one on the tube diagram is part number KRK 112, which uses a 6DV4 (one of those nuvistors) as an RF amp. The sams shows both that tuner, and for earlier models: KRK 66, which uses the 6AF4. The tuner in there is part number KRK 120C. It uses two tubes: the 6CB6 and the 6GK5, both of which, according to my recieving tube manual, are usually used as VHF (not UHF) RF amp tubes. I know those are the tubes that it is supposed to use, as it says so on the tuner itself. I took it apart and it does appear to be a tuner of some sort. Also it is made by RCA, and does fit perfectly in there, however, by the way the wires are connected to it, I can tell it is not original and was a later addition to this set. Maybe this just a later model tuner that was put in there later, by someone who wanted to get UHF, but then it seems odd that RCA would have went from the nuvistor unit to a two-tube unit. I would think that they would have went to a real transistor unit after that, most of the UHF tuners I've seen use a transistor for an RF amp, even in the mid-late 60s. Actually the only kinds I've ever seen are either the 6AF4 units, or the transistorised ones. And I've never seen a tuner with two RF amp tubes before, VHF or UHF.