We all know about the 30BP4, and I know there were 24 and 27" rectangular tubes with the rounded corners in the 50s. But what's the largest b/w rectangular tube (with the more rectangular corners made 1961 and later) that anyone has seen? Was it just the 23" tube? Was there a 25" tube, or were there ever any 23V or 25V b/w tubes in the 70s?

To the best of my knowledge, the 27MP4 (1953-55?) was the only metal 27" rectangular, and the glass ones only had one envelope, despite a few type numbers. There were a variety of 24" rectangular tubes with more and less squared off corners, with both bakelite and button bases (large and skinny necks).

Charles

I'd surmise that large rectangular B/W tube development pretty much quit after around 1964-65 when color sets finally became popular.

I'd surmise that large rectangular B/W tube development pretty much quit after around 1964-65 when color sets finally became popular.

I agree... Those 27" B&W sets were COSTLY, and might have been priced about the same as a mid-60s roundie color set. So that's a pretty clear choice: Trade a few inches of picture size for color. I still saw later model 27" B&W sets in schools and as bowling alley score monitors where a big screen was needed, etc., into the late 70s, and those were probably the last ones made in the late mid 60s.

Charles