Wikipedia:Peer review/Mechanical filter/archive1

Mechanical filter

This peer review discussion has been closed.
I am requesting a peer review of this article prior to submitting it for FAC. I am particularly looking for it to be reviewed for good writing style. It has previously been reviewed for technical content but comments on this aspect are still welcome. This is one article in a series on the major signal processing filter construction technologies. Thanks, SpinningSpark 01:22, 1 May 2010 (UTC)

It's a very technical topic, and such articles are prone to be understandable only if you already know what they say. At looked over it briefly and only felt confident enough to make a minor clarification, but I did notice the lead image was below the text. Would it be possible to flip it to be vertical, and so inline with the text? HereToHelp ^{(talk to me)} 19:40, 7 May 2010 (UTC)

• such articles are prone to be understandable only if you already know what they say. The very reason it is up for peer review.
• Lede image orientation. Certainly the image could be turned round with a few minor adjustments. But why is its present position a problem? It fills in the otherwise blank space next to the TOC. Also, although turning it round would not stop it from being meaningful, it would piss off any engineers reading the article who expect any sort of signal processing diagram to conform to the convention of input on the left and output on the right. Some would count this as a good thing of course....
• SpinningSpark 22:40, 7 May 2010 (UTC)

Oh ok. Thank you, and hopefully Finetooth can be of more help than me. HereToHelp ^{(talk to me)} 02:23, 17 May 2010 (UTC)

Finetooth comments: I have just enough background (not a lot) to read this with interest and without feeling utterly lost. It's well-written, well-organized, well-illustrated, and probably about as clear as you can make it for a wide audience. My greatest reservation has to do with the lead, which seems to be an essay-type introduction rather than a true summary of the contents of the main text sections. My other comments and suggestions have to do with fairly mundane and nit-picky prose and style issues.

Lead

• A good rule of thumb is to try to include in the lead at least a mention of the main text sections and not to include anything in the lead that is not covered in the main text. I doubt that I could re-write this lead even with the full text in front of me, but I'd want to include at least some mention of resonators, circuit design, and the history of mechanical filters.
• "Steel and nickel-iron alloys are common materials for mechanical filter components with nickel sometimes being used for the input and output couplings." - The "with" plus "-ing" constructions are almost always a bit awkward. Suggestion: "Steel and nickel-iron alloys are common materials for mechanical filter components; nickel is sometimes used for the input and output couplings."
• "Mechanical filters find many applications in radio transmitters and high-end receivers... " - Since filters can't literally find anything, perhaps "have" would be better than "find"?
• "While the usual meaning of mechanical filter is one that is used... " - Perhaps italicize mechanical filter here, thus: "While the usual meaning of mechanical filter is one that is used... "?

Elements

• "Note: the mechanical quantity compliance can be used instead of stiffness... ". - Italicize for clarity, thus: "Note: the mechanical quantity compliance can be used instead of stiffness... "?
• "This has equally valid results, but requires using the reciprocals of the electrical counterparts listed above." - I would remove the comma after "results" since it breaks the natural flow of the sentence.
• "Equivalent circuits produced by this scheme are similar, but are the dual impedance forms whereby parallel capacitors become series inductors and vice versa and so on." - I'd remove the comma after "similar" for the same reason.
• "places the components on the circuit diagram in much the same topology" - Wikilink topology?
• "may be made of large squat shaped pieces" - Should this be "squat-shaped" pieces? Or could "shaped" be deleted? Maybe "squat" says it all.

Piezoelectric transducer

• "It can be used on resonators with other modes of vibration also if the motion can be mechanically converted into a longitudinal motion." -Re-cast as "It can also be used on resonators with other modes of vibration if... "? The "also" seems out of place in the existing sentence.

Resonators

• "This has given way to nickel-iron alloys; primarily to maximise the Q since this is often the primary attraction of mechanical filters rather than price." - Comma rather than semicolon.
• "Such a material will have a zero coefficient of temperature with resonant frequency around that point." - Is "resonant frequency" the correct term, or should it be "resonance frequency"?

Resonator modes

• "When the vibration is in one of the higher modes... "? Is the mode higher? If so, what does that mean? Or does this mean that the vibration is higher? Would this be better as "When vibration is high,"?

Circuit design

• "The transducer drives the centre of the first resonator setting it vibrating, the edges of the disc moving in antiphase to the centre when the driving signal is at, or close to, resonance and the signal is transmitted through the connecting rods to the next resonator." - Too many clauses. Suggestion: "The transducer drives the centre of the first resonator, causing it to vibrate. The edges of the disc move in antiphase to the centre when the driving signal is at, or close to, resonance, and the signal is transmitted through the connecting rods to the next resonator." Also, perhaps link antiphase to Phase (waves)#Phase difference?
• "Figure 3 shows a similar idea with longitudinal resonators connected together in a chain by connecting rods." - Perhaps "involving" rather than "with"?
• "This type of filter is called a disc wire filter by Collins." - Switch to active voice; i.e., "Collins calls this type of filter a disc wire filter"?
• "although mechanical filters down as low as a few kHz are rare" - I think here I would write this out as kilohertz (kHz) since this is the first time that you are using it as a separate word. Might be a good idea to link it to Hertz as well.
• Figures 4b and 5 make a text sandwich, usually a layout no-no, between them. This can probably be fixed by moving Figure 5 down until the text sandwich disappears.

Semi-lumped designs

• "Frequencies of the order of MHz are above the usual range for mechanical filters." - Same comment here about MHz and kHz above.
• The entire first paragraph of this section is unsourced. It's a good idea to provide a source for every paragraph in an article as well as for statistics such as the 15x mentioned in the paragraph. Any claim that is apt to be challenged should also have a source.
• "the coupling wires are made exactly one half wavelength" - Hyphenate one-half since it's being used as a compound adjective?
• "For even higher frequencies, microelectromechanical techniques can be used as described below." - One-sentence orphan paragraphs are usually frowned upon. I think you could safely merge this one with the paragraph above it.

Bridging wires

• The long illustration, at least on my computer screen, has five extremely short lines of text (just one or two words each) scrunched between it and the right-hand margin. It would look much better to begin the text below the illustration instead of beside it.

Microelectromechanical filters

• "Extremely high Q resonators can be made with this technology, flexural mode resonators with a Q in excess of 80,000 at 8 MHz are reported." - Semicolon instead of comma.

Other

• The alt-text tool at the top of this review page shows that the images need alt text. WP:ALT has details. I'm not sure what the best approach here would be since alt text is meant for readers who can't see the images. I don't think a complete description of the details of each illustration would be feasible or useful. You might have to resort to a brief summary of the essence of each illustration. That's the standard procedure for alt text for maps; the alt text states the main thing that the map is intended to show.
• The dab checker finds one link that goes to a disambiguation page instead of the intended target.
• Captions like that in Figure 9 and the lead image don't take terminal periods because they consist solely of a sentence fragment.

I hope these comments and suggestions prove helpful. If so, please consider reviewing another article, especially one from the PR backlog at WP:PR. That is where I found this one. Finetooth (talk) 01:57, 9 May 2010 (UTC)

Spinningspark responses: Thank you. I will give a detailed response in due course, but will be using nearly all of your suggestions. There are one or two that seem to be based on a misunderstanding, but that still means the article needs to be changed in some way to eliminate the confusion. SpinningSpark 08:38, 9 May 2010 (UTC)

• Lede coverage. Can I ask you to have a second look at this, I have had a little try at improving it. Admittedly, I was not particularly thinking of WP:LEAD compliance when I wrote it, but on re-reading I could not find too much wrong. You may need to be more specific. The only bit I found that is positively not in the article was the reference to use in acoustics. I thought it would be good to keep this as loudspeakers are something immediately familiar to everyone. So rather than striking it, I have mentioned this is in the article. History is now covered which I think was the main ommission. You mentioned resonators, these are included in the more general term "components". I could shoe-horn resonator in there, but I could not immediately think of a way to do it without breaking the sentence flow. SpinningSpark 18:52, 9 May 2010 (UTC)

That seems better. However, one sentence doesn't make sense to me as written. Perhaps something got garbled during the re-write. It is: "By the 1950s mechanical filters were being manufactured as a component which for applications in radio transmitters and high-end receivers, particularly the intermediate frequency (IF) stage, mostly because mechanical resonators can be manufactured with a "quality factor" Q far higher than an all-electrical LC circuit can produce." Would deleting "which" fix this? Also, perhaps the sentence could be tightened by deleting "can produce" from the end. Finetooth (talk) 01:40, 10 May 2010 (UTC)

Fixed SpinningSpark 22:34, 11 May 2010 (UTC)

• Elements, done
• Transducers, done
• Resonators, done except for;

• Modes. A higher vibration mode will invariably produce a higher frequency but this is not the meaning of higher mode. It means a higher mode number which is defined by the number of half-waves present, which in turn directly relates, as the article says, to the number of nodes. I am struggling to find a succint way of clarifying that, other than to point to the vibration mode article already linked. Now explained in article.
• Resonant frequency. I have changed this to resonance frequency. You are certainly right that this is the grammatically correct form, however everyone on this side of the galaxy uses resonant frequency, found even in many, possibly most, textbooks. Since an editor seems to have gone through the entire wiki putting all occurences into this form I shall give way. Sorry, could have just made the edit and kept quiet, but I felt compelled to winge.

• Circuit design, done
• Semi-lumped design done
• Bridging wires done
• Microelectromechanical filters done
• Other

• Alt-text done
• Dab checker. That page (guard band) is not truly a dab page, that is, it is not pointing to a better page that the article can use. I have removed the dab categorisation.
• Captions done

• SpinningSpark 23:59, 12 May 2010 (UTC) to 11:35, 15 May 2010 (UTC)

Capacitance/Stiffness: The penultimate paragraph of the Elements section, twice equates capacitance with stiffness - whereas earlier on it said that stiffness was going to be taken as analogous to elastance --catslash (talk) 14:30, 13 May 2010 (UTC)

A solid mechanical component will unavoidably possess both mass and stiffness. This translates in electrical terms to an LC circuit

This is an accurate statement, it does not say that stiffness is proportional to capacitance.

Capacitors may be made of thin, but stiff rods, that is, the mass is minimised and the stiffness is maximised.

This is an error of course, stiffness is minimised. One requires a fat rod for stiffness. Well spotted. SpinningSpark 18:36, 13 May 2010 (UTC)

I think I was looking at It is still possible to represent inductors and capacitors as individual lumped elements in a mechanical implementation by minimising (but never quite eliminating) the unwanted property. [out of mass and stiffness] as the other (more arguable) occurrence. Sorry - I should have taken the trouble to be more specific when I first mentioned it. --catslash (talk) 13:23, 14 May 2010 (UTC)

Yes, it is not clear whether the properties referred are L and C (true statement) or M and S (false statement). I will try to clarify this section after dealing with the Alt text issue above. Unless you want to have a go yourself while I'm doing that. SpinningSpark 17:46, 14 May 2010 (UTC)

I have now clarified all this. I have introduced compliance into the description, which I was trying to avoid, but without using it the sentence structure becomes extremely convoluted and difficult to understand. I have not changed the sentence you highlighted above since the following text now makes it very clear (I hope) which properties are meant. SpinningSpark 11:35, 15 May 2010 (UTC)

• Just wanted to make one final comment on the sandwiching issue. I have fixed this by making all the diagrams in the offending section floating right. However, this is not exactly an improvement in my opinion, the article is much more readable with the diagrams spaced from each other by alternate alignment, even if this means putting up with a small amount of sandwiching. Sandwiching is only a problem when the text is reduced to a narrow column with just a few words. In fact, in any article with diagrams left and right there will be some setting of browser text and/or window size that will result in sandwiching. An overly strict application of this rule is effectively saying no left-floating images are allowed. Any other opinions on this? SpinningSpark 11:35, 15 May 2010 (UTC)