[Boatanchors] sweep tubes (was Re: Galaxy V)

[Dennis DuVall]

With reasonable care sweep tubes can last a long time.  The original pair of 6JS6C sweeps in my Yaesu FT-101B are still going strong after 40 years. I suspect most failures occurred due to 
maltreatment such as holding the key down while thumbing through the manual looking for the next tune-up step.  Saw stuff like that happening at a club station particularly with younger members.

Dennis D.  W7QHO
Glendale, CA

****************





> On Sep 15, 2016, at 8:46 AM, Marvin Match <mvmatch at ece.utah.edu> wrote:
> 
> I find this discussion of amplifiers built with gobs of sweep tubes interesting, especially the idea that it's easy to vaporize the tubes if you fail to tune up quickly or improperly.
> 
> Personally I've always felt that sweep tubes were being abused when used as RF output tubes in a rig or an amplifier . . .
> 
> However, I've always been curious about the GE 8950. It was marketed as an RF output tube, but as far as I can tell, it's just a sweep tube like all the other sweep tubes. The inter-electrode capacitances  are lower than some sweeps, but otherwise they smell and taste just like sweep tubes to me. Even in the spec sheet, although the description is "linear amplifier and RF PO aplications
> 
> Just wondering . . . is anyone aware of differences that make the 8950 a real transmitting tube, like heavier glass, or thicker plates, or are they just sweep tubes with a different marketing campaign?
> 
> Marvin KA7TPH
> 
> 
> 
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