Is it OK to mount a cap like this?????????

[laatsch55]

Low level, high gain tube pre-amp. Peruse the pics, the big black cap with lead running all the way down the side, will that be a big, bad inductor??

 

[Gepetto]

I would guess that the capacitor's internal self-inductance is probably larger than the inductance of that lead wire Lee.

 

[laatsch55]

Even though the leads are different lenghts??

 

[laatsch55]

Being this close a tube can't be good.

 

[stuwee]

Are you talkin' about heat wise? Lee, most preamp tubes don't run very hot, just slightly warm. Most, if not all of the tubes in Gramps Pilot console in the pre/tuner section were original from 1959. Now if that was an output tube in the amp section...Sizzzzzle POP!!

 

[mlucitt]

Lee, the problem I see is not inductance but that lead will act like an antenna and pick up WWV in Colorado. Perhaps you can put a ferrite bead on it, wrap it with moleskin (moles have a negative skin polarity), or smear some crude oil from 6000' down on it.

Just kidding. I have a preamp like that one and the polypropylene caps are just so large that they get in the way. I hate to mount them that way with long leads, but what are you going to do?

I would slide a tube shield over the tube that is almost touching the cap tho'

Mark

 

[speakerman1]

If you are going to do it that way. Just shrink tube the leads.

Larry

 

[laatsch55]

Thanks Guys.

 

[laatsch55]

Yes Stu, was worried about the tube heat.