Talk:Tetrode

Are there any diagrams/photos of valve tetrodes on WP?--Light current 03:39, 20 January 2006 (UTC)

Merge Screen grid into Tetrode

Agree Pol098 (talk) 23:20, 16 March 2009 (UTC)

plate characteristic curves

I enjoyed reading the the article. I think it gives an excellent understanding of the purpose and uses of the extra grids. The only thing I thought was missing was a set of typical plate characteristic curves. The triode article does include one. The tetrode and pentode plate characteristic is very different from that for the triode, and I think the comparison is illuminating. I believe that most designers working with electronic amplifiers rely on these graphs. As many readers may know, this sort of graph is useful enough that there is actually an instrument called a curve tracer designed specifically to create them (although these are not generally sold for vacuum tubes). --AJim (talk) 14:53, 12 May 2009 (UTC)

Merge Beam Tetrode into Tetrode ?

Opinions ? G4oep (talk) — Preceding undated comment added 10:24, 6 January 2015 (UTC)

• Support. Beam tetrode is no more than a large stub. Expanding it into an adequate article would require a great deal of duplication of content in this article. The two tubes should be treated in the same article. --Chetvorno^TALK 11:14, 6 January 2015 (UTC)
• Support, I guess Meh Slightly oppose - this article (tetrode) is already 25 K, beam tetrode is 7 k - on the other hand, some of the content that would be brought over is already duplicated here, so perhaps the merge won't make the result too long. Oh, go ahead, if some keener writes 65000 bytes of brilliant referenced prose on the history and economic effect of the beam tetrode, we can always split it off later. I'll put the tags on, must follow sacred procedures. --Wtshymanski (talk) 14:45, 6 January 2015 (UTC)
• Strongly Oppose. A beam tetrode and a tetrode are not the same thing and have very different characteristics. If a merge was on the cards, then it would be more appropriate to merge beam tetrode with pentode as it has a much closer affinity. The article even compares it with a pentode. It should be remebered that the beam tetrode was developed by MOV solely to side step Philips's patent on the pentode (though having been developed has many desireable characteristic - so much so that many valves officially described by their manufacturers as pentodes are, in reality, beam tetrodes)). On the other hand no tetrode valve would ever be built as a beam tetrode because they are so completely different. 31.48.73.38 (talk) 16:47, 6 January 2015 (UTC)
• Oppose. Like the IP above. --Wosch21149 (talk) 22:24, 6 January 2015 (UTC)

• Re the points made by, 31.48.73.38 I have added some material to the present page relating to beam tetrodes with pure tetrode structure and no beam plates. As indicated in the text, these tetrodes were built as beam tetrodes, and explicitly named as such by the manufacturer. This type of beam tetrode is very familiar to HF & VHF power amplifier users, though valve audio buffs might not be aware of it. I can sympathise with the point of view that beam tetrodes with beam plates could (maybe should) be classified as pentodes, since the beam plates definitely form a fifth electrode system, and their function is identical to that of the suppressor grid, although their mode of action is quite distinct. On the other hand, beam tetrodes without beam plates cannot be classified as a type of pentode if the etymology of these terms is to retain any significance (4 vs 5 electrodes). So perhaps, in addition to the established naming system, the question hangs on whether beam tetrodes with beam plates have enough in common with pure tetrode beam tetrodes for them to be classified together. The similarity between them, and the common distinction from pentodes lies in the use of a space-charge electron beam to prevent secondary electrons from reaching the screen grid at low anode voltage. Pentodes achieve this result with a completely different technique. 77.96.60.31 (talk) 15:11, 7 January 2015 (UTC)G4oep (talk) 17:38, 7 January 2015 (UTC)

Tetrode Assessment

The following was posted to my talk page. I think it best to respond here. ~KvnG 22:34, 10 January 2015 (UTC)

Thank you for looking at the Tetrode article and responding to my request for a reassessment. One of the reasons for my request was to gain some experience in the way in which the criteria for assessment are applied, and what you have done has helped. I do not like to presume too much on your time and effort, but it would help me further if you were to give some comments on the deficiencies in the article. Do they lie in the referencing (largely historical, and difficult to access), the inclusion of irrelevant material (such as my explanation of the superhet), omission of needed relevant material (if so what new material should be included), general organisation & presentation - I have aimed at the Class B criterion of avoidance or explanation of technical language; does this detract from the required style, or augment it ? I would like to become more proficient as a Wiki editor, and if you could help me to focus on what is required, using this article as an example for honing my skills, it would be a great help. If you are sufficiently interested in this topic to provide detailed criticism, we could, perhaps co-operate in raising the quality further; I would do the necessary research and editing, of course unless you want to contribute to that as well. The history of thermionic tubes is of considerable interest to me, so I would be quite happy to research this further - I have already learned a lot. G4oep (talk) 10:47, 10 January 2015 (UTC)

I've given the article a c-class rating. As far as what can be done to reach b-class, see Wikipedia:Version_1.0_Editorial_Team/Assessment/B-Class_criteria. The article, as it stands, is weak on structure, writing and accessibility. We need to fully resolve the Beam tetrode merge issue. The prose needs to be tightened up. We need to get feedback from non-technical readers as to sections that are difficult to understand without sufficient electronics background; Start with the lead here. Have a look at Vacuum tube as an example of something closer to a b-class article (technically, a true b-class article should not have any maintenance tags). Achieving b-class is actually a fairly big deal for any article. ~KvnG 22:46, 10 January 2015 (UTC)

Thank you for your comments. I appreciate the trouble you have taken. I have changed the title of the anode characteristics section to make it clear that this is not a digression, but is an essential link between the screen-grid & beam tetrode sections. In other respects I feel the structure is sound - I introduce the 3 types then describe them in historical order. However you have not commented on the inclusion of the superhet material. Re "accessibility" are you referring to the references, many of which are historical ? Many of these (for example the references to early C20 patents), are important when questions of priority are considered, and are also important primary sources. However, many of them are referred to in Thrower, which I believe is still in print. Do you feel that it is better to quote modern secondary sources rather than rare and difficult primary ones ? Since valve technology is now only of historical interest modern textbooks covering this topic (for example an alternative to Terman) simply don't exist. Finally, would you like to comment on the merger question ? Presumably, if it is to be answered, the more fors or againsts the better. — Preceding unsigned comment added by G4oep (talk •G4oep (talk) 17:37, 11 January 2015 (UTC)

I don't have enough expertise to weigh in the merge proposal. There doesn't seem to be consensus or consistency on how to represent the relationship between tetrode, pentode and beam tetrode. I have made some improvements to the lead to improve accessibility. ~KvnG 19:27, 11 January 2015 (UTC)

The relationships between pentodes, tetrodes & beam tetrodes

This is how I see it, and I would like to invite the comments of others.

1) Tetrodes are best defined as valves having 4 electrodes. Examples are those I have given, including beam tetrodes which do not have beam plates. Exclude beam tetrodes with beam plates for the time being. With that exclusion, don't expect the rest to be contentious.

2) Pentodes could be defined as: (a) valves having 5 electrodes. (b) valves having 3 mesh grids, an anode and a cathode. I prefer the former definition.

3) That leaves beam tetrodes with beam plates (BTWBP). My view is that logically these should be classed as a type of pentode, since this would fit my preferred definition of a pentode. However, historical usage is against this; "beam tetrode" is an established term which has been used to refer to these types since their invention, and the term is still current. It is no use for me, or anyone else in the modern world, to try to change this - we are stuck with it, however illogical it might seem. Historically it is easy to see why BTWBPs were not classified as pentodes. The at the time of the invention of the BTWBP, the name 'pentode' had already been claimed and the device patented; it was a valve with 3 grids (definition 2b). The BTWBP was a separate invention with its own patent, and the manufacturers established a legal right for it to be distinguished from a "pentode" as a consequence of its separate patent, and distinctly different mode of operation. To my mind, this explains why a BTWBP is not a "pentode".

4) The term "beam pentode" would seem appropriate for BTWBPs, but it is rarely used. The only example I have found is this: http://www.soniccraft.com/datasheets/WingedC_6550C.pdf

I therefore propose that in agreement with generations of valve users before us, we accept the historical terminology.