Probably because sweeps are pulse tubes and are not built to take high levels of average power. The 6146 and such were more robustly built and would typically be used in FM or AM service.
On Thu, 03 Apr 2025 00:06:42 +0000
"Steve Wedge, W1ES/4 via groups.io" <w1es@...> wrote:
I don't know where the perception that sweep tubes are delicate came from. They're really not any more delicate than the famous 6146.
--
73
-Jim
NU0C
Jim Shorney