Modern Electronics (was Re: List charter mods & headcount... ; -))

On Mon, 21 Jun 2004, Kevin Handy wrote: sigh.... I ain't gonna get into a rant about modern electronics / science "education" nowadays... but could perhaps I offer a small logical trail, in response to the above assertion? If your tubes, envelopless, are already in an ambient vacuum - interplanetary space, the surface of the moon, etc - pray tell me what there is to 'insulate' against? What precisely, would be the mechanism of the 'cross-talk'? Now, granted, any electromagnetic, or even mechanical, disturbances could still be propagated between these envelopless tubes, but this holds true whether or not the glass is there. To pick nits, there would be added element structure suppport issues, as many tubes use the inside of the envelope to support the micas, or other parts, but that is a mechanical design problem, and does not bear on the actual operational characteristics of the said envelopeless, designed-to-operate-in-an-ambient-vacuum thermionic emission active device. I have participated in the design of more than one 'tube', which we built on the base of a bell-jar, then pumped down to check the operation, then re-admitted atmosphere to make adjustments - as in fact most tube design work is done (at the physical prototype level). Nothing changes electronically, physically there are plate heat radiation differences, some exposed element effects... but I can tell you that a quad of 6L6GCs, having had their glass envelopes carefully removed, operate as per spec when relocated to a bell jar (and thus in a vacuum of calibratable 'hardness' , hint hint hint...) Okay, my contribution to off-topicness is done now. Cheers John