Hi, Gang

The 6JB6 tube used by Drake seems to have the same specs
as a 6DQ6B (octal) sweep tube. Pretty wimpy.
The 6JB6 has a button stem base, and therefore
should be a better high frequency performer than the 6DQ6B.

The 6DQ6 was favored on low-end rigs like the Heath DX-20
or Knight Kit T-60. The Hallicrafters SR-150 used two 12DQ6B's.
The 6DQ6B was a bit beefier than the original 6DQ6 or 6DQ6A.

Sweep tubes are really good at surviving abuse,
at least for short periods. I was trying to tune up
a newly aquired Swan 240 beater, and my first indication
of an intermittant plate meter was the red glowing plate
of the single 6DQ5. I thought that tube was a goner,
but it still worked fine, a hundred watts out with a whistle.

73,
Ed Knobloch