There were wood top coils before and after the brass topped ones. Can any one say why this "complication" or addition of the brass plate came about? I understand they were KW's.
LOL (Laughing Out Loud)!
I don't know the answer to your question. However, since I am all this week working on repairing several of them for my two brass era T projects, I would like to know also. You should see the horrible tarry mess my work bench is in!!!!
Drive carefully, and enjoy, W2
Actually Heinze and Jacobson Brandow coils that came before the "brass top" coils had metal plates at the top. Not sure about Kingston but the KW patent claims that the metal tops reduced "eddy" currents but I think they had some wrong info. The lack of brass during WW1 made it hard to get the stuff so finally somebody just built a coil without any metal top and it proved that the metal top really wasn't necessary.
I agree, eddy currents in a non ferrous material doesn't make sense to me?
Ron the Coilman
Wayne I do that stuff out side. I use a metal can with a spout bent in it & held by a pair of vice grips. Heat is a propane torch. I don't re-fill the now mostly empty space left by the new capacitor. I fill most of it with wood bits cut to size then pour in the tar. I usually have enough left from what I removed to re-fill the coil. No lingering odors or mess. As to Ron & John's answers above: I guess you guys should know but it seems strange they'd pull this idea out of air so to speak considering all the extra parts needed. The plate itself plus all the additional insulating gaskets and washers. Were they more expensive than the wood tops?
In fairness to those engineers they didn't have the type of test equipment we have today. In a few moments one can pretty much see exactly how something is or is not working as per the "theory of operation". When something worked then as now a manufacturer is not inclined to want to change anything. They are even less inclined when the item is not that well understood and it is obvious that not everyone had a good understanding of how things worked. I am currently researching Splitdorf company and their coils seem very over designed based upon what we know today but during that era they were considered a most knowledgeable company with regard to early electrical items. I like to think of something that Ronald Reagan said about his opposition party and generally what he said was that "it isn't that they don't know anything but rather that much of what they know isn't true" My quotation is not verbatim what he said but leaders in a fledgling field are not inclined to admit what they don't know since they want to remain the leader. It often comes out later that they had no clue how something actually worked but just that it did work.
I know you believe you understand what you think I said but I am not sure you realize that what you heard is not what I meant..
I'm starting to think that just maybe they just came up with a "non-improvement improvement" to boost sales. They sure wouldn't have been first in the wild claims/add-ons area. Any body that read through the old JC Whitney catalogs knows it continued for years. And still does. Since no one's answered the price question I have to assume they cost more than a standard/wood top coil.
Off Thread, but Charlie mentioned JC Whitney catalogs & "non-improvement improvement" I still remember leafing through one years ago, and on one page was a "hidden Cell-phone antenna to fool thieves" makes it look like you don't have a cell phone to attract them. On the next page was "Get that Cell-phone Look with this fake antenna! Sticks easily to your trunk top!"
Ooooh Kaay. . . .
John, the three different Kingston coils used 1909-13 had black "fiber" tops glued to a wood base.