Jump to content

Talk:Crystal oscillator frequencies

Page contents not supported in other languages.
From Wikipedia, the free encyclopedia

RC channels don't belong

[edit]

Surely all these channels are now synthesized, not individual crystal oscillators? We also have the problem that RC allocations vary in different parts of the world. Put the frequencies in a List of radio control frequencies, not here.

This list is pointless in any case since you can make a crystal for any darn frequency you want, to a hundred megahertz or so, and I don't see the encyclopediac value of reiterating the world's list of frequencies here. --Wtshymanski (talk) 13:40, 21 April 2010 (UTC)[reply]

Yes, individual oscillators. These are taken from a list of a RC equipment retailer (see the reference link from the first frequency at each set). Many retailers sell these crystals; they usually come in pairs, one for the transmitter and one for the receiver, or in entire sets with several pairs for different frequencies. Apparently in such applications it is still easier/cheaper to swap crystals instead of using something more complicated. This may change in the future. As of now, these crystals are commercially available in large amounts from many sources, hence the inclusion of the entire sets. Of course you can get custom crystals made, but these won't be available for few bucks from many major sources, which is my criterium for inclusion. If a search for a frequency yields several stores offering such crystal, I consider it important enough. Good idea for the frequencies. --Shaddack (talk) 01:13, 23 April 2010 (UTC)[reply]

Propose for deletion

[edit]

What is the point of this list, again? You can make any frequency in a crystal oscillator. What is our encyclopediac purpose in a list of all the world's crystal frequencies? It's about as valuable as a list of licence plate numbers. --Wtshymanski (talk) 16:05, 7 July 2010 (UTC)[reply]

Arguments against deletion

[edit]

Use case 1

[edit]

I wanted to use a microcontroller that was specified up to 16MHz as fast as possible while also being compatible with high-speed UART communication. So I entered the table at 16MHz and went upward until I found the 14.7456 MHz one.

Without that table, some elaborate arithmetics (playing with prime factors) would have been neccessary to find an eligible frequency. Even then, the result would still have to be checked against *some* table (vendor catalogues), since only commodity frequencies are at available at 20¢. --77.3.116.222 (talk) 13:56, 27 April 2011 (UTC)[reply]

Use case 2

[edit]

I wanted to make some software defined radio experiments by recieving and decoding PSK31. There are ten common frequencies used for those transmissions.

The quadrature mixer I wanted to use for decoding needs about four times the frequency the information is transmitted at.

The tabled made it possible to quickly identify 14.318 MHz as a common (and thus cheap and available in small quantities) quarz that, divided by four, yields a PSK31 frequency. --77.3.116.222 (talk) 13:56, 27 April 2011 (UTC)[reply]

Use case 3: Where to salvage specific crystals

[edit]

Speaking of that 14.318 MHz crystal. The table also mentions use in PC mainboards and VGA cards, so I went to the box in the attic collecting archaic computer scrap and could find 5 crystals and one socketed crystal oscillator waiting to be pulled. --77.3.116.222 (talk) 13:56, 27 April 2011 (UTC)[reply]

Another argument against deleting this page

[edit]

Just because its not useful to you doesn't mean its useless. I have found this page invaluable. If it was just a list of frequencies that crystals have been made in I agree it would not be as useful. But because beside the frequency it has uses and reasons FOR those uses it is actually extremely valuable information. Just the sort of thing people go to an encyclopedia to look up in fact. RF Wizards, crystal 'healers', and people with no interest in electronics will not need this page either because they already know whats in it or they don't care - but for those of us in the middle it is an excellent resource. — Preceding unsigned comment added by 185.32.110.17 (talk) 17:41, 3 June 2019 (UTC)[reply]

Additional Comments from a casual ie non-editing Wikipedia user

[edit]

I just wanted to add that as a user of Wikipedia (who knows nothing of its conventions etc) I was alarmed to see someone wanted to delete this page. Personally I find it very useful; it has helped me enormously when sorting through my mixed crystal salvage tub deciding what to keep. It has also helped me identify the function of several unknown PCBs and modules, purely by being able to see what the most likely use for a certain frequency oscillator is. PLEASE don't delete it! Its not like this is a physical encyclopedia with a limited page budget. This is very useful information, please keep it. I will add to it myself if I come across any that are not already covered. I have just copied the page to local storage just in case it gets zapped. Perhaps if someone adds a section on what crystal oscillator frequencies will make various chackras vibrate correctly the New Age crystal mafia will leave this alone? — Preceding unsigned comment added by 185.32.110.17 (talk) 17:29, 3 June 2019 (UTC)[reply]

Further voice in the choir
Basically I echo the above. I'm not even in a position of being able to indulge in relevant activities physically, but having all these in one place to refer to makes life a hell of a lot easier when trying to do design thought experiments or engage in discussions helping those who can, offering suggestions etc, where my main help can be that of research and consideration rather than doing. I ended up here today because of trying to work out what a 12.288MHz oscillator might be used for, and having drawn a blank everywhere else on the internet. I can now tell you two dozen different places to *buy* one from, but this is the first location I found any indication of what it's actually for and thus what machine, or part of it, an isolated one found in a bucket of parts may have come from, and thus what it may be good to reuse it for... I'm sure I could find many pages similar to this on WP that are dedicated to subjects I have absolutely no knowledge or experience in and go make a nuisance of myself calling for them to be deleted, even though as plain text tables their total data makes up a small fraction of, say, a single raw-resolution PNG photo of a certain mountain pass road in Italy I came across elsewhere on the wiki a couple days ago (17MB when downloaded...!). But I'm not that narrow minded. 92.7.51.148 (talk) 04:29, 29 June 2022 (UTC)[reply]

Commonly made frequencies

[edit]

While it is technically possible to make just any frequency, that does not mean that all are commonly made. And given a random selection of a 1000 bought/salvaged crystals, probably 500 will have frequencies found on this list.

Maybe, though, the list should be renamed to something like "common clock/carrier/LO frequencies in electronics" — Preceding unsigned comment added by 217.226.229.137 (talk) 07:52, 18 December 2011 (UTC)[reply]

Agreed. Or alternatively this list could include a binary column for "obsolete" and/or a binary column for "commonly available crystal" so readers can get a feel for what crystal frequencies actually are in use nowadays. I suspect a lot of these clock frequencies aren't actually from a crystal but rather are generated from PLL clock multiplication.
I am also suspicious of the frequencies listed sugnificantly higher than 100 MHz. Looking at the worlds largest electronics component distributor's selection of crystal oscillators (https://www.arrow.com/en/categories/oscillators-and-crystals/crystals-and-resonators/crystals) I see the highest purchasable frequency listed is 216 Mhz, while the highest with significant volume is only 80 MHz. And the article Crystal oscillator anyway says "Quartz crystals are manufactured for frequencies from a few tens of kilohertz to hundreds of megahertz". Meanwhile this list suspiciously goes up to 1 GHz. The application listed for that is 4K VGA at 120Hz, but I don't think anyone actually used a different crystal oscillator for each different video resolution pixel frequency. So I suspect that 1 GHz clock was really from from clock multiplication of a lower-frequency crystal oscillator. (Anyway nowadays HDMI maximum pixel clock is 600 MHz and DisplayPort's maximum clock is 810 MHz, according to https://www.monitortests.com/blog/common-pixel-clock-limits/) Em3rgent0rdr (talk) 16:38, 27 December 2022 (UTC)[reply]
[edit]

Hello fellow Wikipedians,

I have just modified 6 external links on Crystal oscillator frequencies. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

This message was posted before February 2018. After February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than regular verification using the archive tool instructions below. Editors have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the RfC before doing mass systematic removals. This message is updated dynamically through the template {{source check}} (last update: 5 June 2024).

  • If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
  • If you found an error with any archives or the URLs themselves, you can fix them with this tool.

Cheers.—InternetArchiveBot (Report bug) 03:57, 15 August 2017 (UTC)[reply]

Are changes actual crystal/oscillator frequencies?

[edit]

Hey User:Shaddack, are all of the following changes actual crystal/oscillator frequencies that can be purchased? • SbmeirowTalk18:18, 10 June 2020 (UTC)[reply]

https://en.wikipedia.org/w/index.php?title=Crystal_oscillator_frequencies&type=revision&diff=961826060&oldid=955579696

Let's delete anything that doesn't have a referenced source. I very much doubt there's a single-package crystal oscillator running at 1075.804 MHZ for VGA clock generation - this frequency is probably generated deep within an IC package, multiplying some external reference. --Wtshymanski (talk) 21:59, 10 May 2021 (UTC)[reply]

Would this be a place to ask about the reasoning for certain frequency choices?

[edit]

...where it's known by *someone*, and that could then maybe be added in brief form to the descriptions, even?

Like, I figure that if there's anywhere that can finally answer the question of why the heck IBM went with 16.257M for their MDA and EGA cards rather than a more common existing 16.x frequency (like it's common *because* of the once extremely common nature of those video standards, but basically nothing else that I've found; at least the Mac one makes sense as it does double duty dividing down to serial baud rates, and the PC system frequency + CGA is based off NTSC), it's probably here? But that's just one of many mystery rates... 92.7.51.148 (talk) 04:33, 29 June 2022 (UTC)[reply]

Oh no, of course not. This is the Wikipedia parts catalog. We will tell you every single integer up from 32768 as a crystal frequency but never tell you why any particular frequency is needed. Parts catalogs are always missing the theory and rationale. We love parts lists on Wikipedia, we do. None of these numbers are fundamentally significant - some frequencies get made for common applications, but there's nothing fundamental about any of this. --00:56, 7 July 2022 (UTC)
Just a reminder that Wikipedia talk section aren't a place to ask questions about old product designs. I'm sure there was a reason, but this isn't the place to ask the question. • SbmeirowTalk02:10, 7 July 2022 (UTC)[reply]

Video chipset crystal

[edit]

RCA/Harris CDP1869/CDP1870 chipset with composite color (NTSC) output. Used 5.67 MHz xtal for video timing (dot clock) and 7.15 Megahertz (2x color burst) for color. Also did PAL with different xtals. The number of horizontal chars equaled VGA at half horizontal freq and 5.67 MHz exceeded ntsc STDs. 174.253.193.9 (talk) 06:03, 1 January 2023 (UTC)[reply]