Talk:6L6

813
813 as a derivative of the 6L6

Whilst I agree that the 807 is basically a 6L6 with a top-cap and a different base, I don't believe the 813 is a 6L6 derivative. Comparing the 6L6 with the 813, about the only thing they have in common is that they are beam tetrodes. Does anyone have a reference stating the relationship between the 6L6 and 813.
 * --PeterJeremy 06:49, 2 January 2006 (UTC)

Are you a TCA member? Have you ever asked Lud Sibley about this? I have. Lud is the current director of the RCA Archive. If anyone knows how the 813 came about, he does.
 * --EricBarbour 11:13, 2 January 2006 (UTC)

I'll accept that as a valid reference. I am surprised because the 6L6 and 813 appear to have very little in common.
 * --PeterJeremy 00:02, 4 February 2006 (UTC)

It should be understood that if 6L6 is the first production beam power tube, any other beam power tube is based on it in some way. —Preceding unsigned comment added by 67.171.250.144 (talk • contribs) 06:32, 5 August 2007 (UTC)

EL34
I removed this from the article.

"**note to original author - the EL34 was released some 10 or more years after the 6L6, although Philips did have pentodes in the 1930s. An example of an American pentode which preceeded the 6L6 is the 6F6G**"

I don't know what to do with this info. Someone more informed should edit the article if it is wrong.
 * Adam850 20:03, 4 November 2006 (UTC)

The EL34-maven does not understand that Wikipedia articles should contain verified information, not disputes. If there is a dispute about the date of the EL34 (which I believe to be late 1940s or early 1950s--the article almost certainly *is* incorrect) then it should be carried out here in the discussion, or possibly become a Wikipedia topic of its own, something like "EL34 History Dispute". The Wikipedia article on the EL34 does not contain any history. Perhaps someone who really cares (hint, hint, that's you, 12.0.37.66) can research it and update the articles for both the 6L6 and the EL34.

I removed 12.0.37.66's comment from the article:

"**(incorrect, the EL34 was developed LATER)**"

Snezzy 14:36, 13 February 2007 (UTC)

The problem with this article is that it is from a British point of view. Nowhere is mentioned that RCA engineers had to work the design over quite a bit to create a mass-produceable design. RCA also had no need to get around Philips patents. Only after RCA finished the product did any British company go back to the beam power design. The EL34 was a Mullard item to get around the new MOV 'KT' patents in 1954. The main reason EL34s historically have screen-grid heat problems is that Mullard deliberately did not align the grids, because of MOV patents on such things. Thus, MOV answered with the KT77, which has aligned grids. By this time, any pentode patents held by Philips were expired. All of this can be found in relevant articles in Vacuum Tube Valley. —Preceding unsigned comment added by 67.171.250.144 (talk • contribs) 06:32, 5 August 2007 (UTC)

Reason for metal shell
I am under the understanding that the reason for the metal shells had to do with making the equipment more compact. The metal format eliminated the Long ""Press" that had been used up till then in making Glass tubes. At first the leads were on individuals islets on a metal ring, which was welded to the shell, later a glass disk simalar to the Miniture tube concept was used.

In the case of the 6L6, the metal tube is about as long as the glass tube to allow for disapation, but other metal tubes (say the 12SA7), are shorter than the equivelent Glass version.

Now can someone find a reference for this? cmacd 12:51, 30 May 2007 (UTC)

More photos
Hi, if you think that is good idea feel free to paste into 6L6 page some of my pictures of my tubes in my amp

http://img340.imageshack.us/img340/8949/dsc0214mq0.jpg

http://img459.imageshack.us/img459/4579/dsc0206us9.jpg

http://img459.imageshack.us/img459/6421/dsc0208qc7.jpg

It looks nice :)

In case any question email me @ my_nick (at)gmail.com

FurioSan

Photo of metal 6L6?
This article would be significantly improved with a photo of the metal 6L6. I think that was the original, so it's historically important. FurioSan's photos are of a glass-envelope variant of the 6L6. Oaklandguy (talk) 09:45, 6 June 2013 (UTC)

Groove Tube is a US manufacturer?
I beleive they are not a manufacturer, they "select" tubes just as many others do from any source through testing. 97.104.168.124 (talk) 17:16, 14 March 2011 (UTC)

Micanol link is broken
I was curious about the Micanol low-loss base. I clicked the embedded link and got Error 404. The following excerpt (from this link: http://www.antiquewireless.org/uploads/1/6/1/2/16129770/10-the_vacuum_tube.pdf) appears authoritative and covers Micanol pretty well: "Micanol, a mica-filled phenolic, was used for high-frequency applications, particularly on power tubes. Micanol has extremely good dc-resistance characteristics; it is, however, extremely difficult to mold and is more expensive than the other materials..." (I omit the last word "...described.", because other materials are described in the article; Bakelite, Phenolic, Durez, and Plaskon appear most noteworthy. An old RCA recipe for making 200 Lb batches of basing cement is also included.

Micanol is further described in the same article: (Formatting: carriage-return, set tab .5" inch to right) Micanol was the material that admirers of National Company receivers will recognize as "R-39" material. It had the virtue of not absorbing water vapor, and thus was important for high-stability oscillator tubes like the 1626 and 6SJ7Y. (Water has a dielectric constant of 80, and so is unhelpful in terms of the capacitance of an insulator like a tube base.) Micanol was also an effective RF insulator, helpful in the 6146 power amplifier. It had good resistance to high-voltage breakdown, and hence appeared in the 5R4GY rectifier. (Formatting, end tab .5" inch right, carriage return)

The reference section shows: "Micanol Bases - Purchasing Specifications," Confidential S. N. 33C-M-60, p. 1, Nov. 2, 1943 (Online search for this reference proved futile.)

Micanol also appears to be a pharmaceutical brand or product name.

I suggest the Micanol definition of interest, as it applies to tube base material, should appear within Wikipedia for use globally. I nominate the above source material for qualification as the basis for a unique Wikipedia page. Admittedly the cited PDF file relates to frivolous litigation. I believe it contains enough relevant information to be cited as an authoritative source. This is not for me to decide, as I'm new to this. If there is any interest, I will gladly perform data entry. I can do some formatting. I lack guidance on source requirements, pointing to exact lines within a cited publication, formatting standards, seeking consensus, pre-press comment period, finding other Wikipedia pages with the same broken link (the 6V6 page probably also shares the same broken link), and discussion etiquette, etc. I would like to learn to create complete Wikipedia pages. Reading fine print might get me knowledge I need for doing this. But getting off easy is my primary goal. Executive dysfunction might be my problem; I tend to crank out reams of fluff quite effortlessly. I am always looking for good mentors. Untapped capacity lays fallow here, at least in me. I am the perfect canary for every coal mine. Tracking obstacles to my progress might prove helpful in streamlining the Wikipedia-author matriculation process. Short of connecting me to a polygraph machine, I'm a willing guinea pig for testing the Wikipedia indoctrination process. I suggest required reading (fine print) is presently too scattered for use by the lazy (minded like myself).Jeffreagan (talk) 20:24, 6 December 2017 (UTC)