Products > Test Equipment

Most accurate signal generator

<< < (8/34) > >>

Anthocyanina:

--- Quote from: loop123 on March 26, 2024, 05:59:05 am ---
--- Quote from: Bud on March 26, 2024, 04:50:43 am ---
--- Quote from: loop123 on March 26, 2024, 01:16:20 am ---Also why is it hard to make accurate sine wave generators. Dont you just need a crystal for clock. Is it not a crystal is very accurate like used in processor.
--- End quote ---
Processors do not give shit about clock accuracy.

--- Quote --- Its not like you have to synchronize it with the frequency of pulsar star.
--- End quote ---
With your requirements it seems this is what you have to do, i.e. use a GPS disciplinned oscillator, or a rubidium oscillator. Do your research how to build them or how much a commercially built one may cost.


--- Quote ---  Are you saying crystals used in clocks in processor or adc are dirty or not pure so the output from mechanical oscillators are not unform??

--- End quote ---
Crystals have large (compare to your requirements) temperature, tolerance and aging drift. To satisfy your requirements you need a different frequency reference 1000 times better. Crystals will change frequency when you look wrong at them.

--- End quote ---


You mean its difficult even to produce accurate 1.8V sine wave?  Is the voltage or sine wave more difficult to make or which one is more affected by a crystal/clock? usually what are the errors in crystal just to have an idea? but then if crystals vary how do wifi or cell phone even connect?

--- End quote ---

making a sine wave is ridiculously easy, making a sine wave 1.8v in amplitude is easy, making a sine wave within the frequency range you need is also easy, but, making it precisely 1.8v to the 10uV of deviation you want, and within the 10uHz you want, that's where it approaches the physically impossible if not already there, and absolutely impossible for 200$, but also it is very unlikely that you (or most people) need a signal source with those specifications.

crystal frequency can vary depending on temperature, pressure on it because of minor PCB bends and how the materials bend differently due to temperature changes, other factors can also influence the frequency stability of the crystal, maybe minor defects in the crystal structure itself, in the manufacture process...

those radio systems can connect because they have a tolerance range that accounts for the physically, practically and economically realizable components and designs.

and about the voltage stability, a big reason why AM radio sounds so bad when compared to FM radio, noise is everywhere, and gets everywhere, and you see that in the form of variations in amplitude. if you capture a single period of a sine wave, it will not be perfectly sinusoidal, but you'll see it's a bit "frizzy", its amplitude at any x point deviating slightly from what you'd get from calculating sin(x)

loop123:

--- Quote ---
--- Quote from: Anthocyanina on March 26, 2024, 06:19:48 am ---You mean its difficult even to produce accurate 1.8V sine wave?  Is the voltage or sine wave more difficult to make or which one is more affected by a crystal/clock? usually what are the errors in crystal just to have an idea? but then if crystals vary how do wifi or cell phone even connect?

--- End quote ---

making a sine wave is ridiculously easy, making a sine wave 1.8v in amplitude is easy, making a sine wave within the frequency range you need is also easy, but, making it precisely 1.8v to the 10uV of deviation you want, and within the 10uHz you want, that's where it approaches the physically impossible if not already there, and absolutely impossible for 200$, but also it is very unlikely that you (or most people) need a signal source with those specifications.

crystal frequency can vary depending on temperature, pressure on it because of minor PCB bends and how the materials bend differently due to temperature changes, other factors can also influence the frequency stability of the crystal, maybe minor defects in the crystal structure itself, in the manufacture process...

those radio systems can connect because they have a tolerance range that accounts for the physically, practically and economically realizable components and designs.

and about the voltage stability, a big reason why AM radio sounds so bad when compared to FM radio, noise is everywhere, and gets everywhere, and you see that in the form of variations in amplitude. if you capture a single period of a sine wave, it will not be perfectly sinusoidal, but you'll see it's a bit "frizzy", its amplitude at any x point deviating slightly from what you'd get from calculating sin(x)

--- End quote ---

No. I just wrote 1.00001V to drive the point that it should not be 1.2V or 0.9V but exactly 1V. It doesn't have to be 1.00001V but only 1.01 volt for example. It is enough. With that clarified. I just need a sine wave generator that can produce 1.8V (error of 1.801V) and 5000Hz (not 5001Hz or 4999 Hz). How do you build them anyway? Since I'd rarely use it. My budget for finished product (I want ot avoid building it) is lower to $50..

ebastler:

--- Quote from: loop123 on March 26, 2024, 06:48:42 am ---No. I just wrote 1.00001V to drive the point that it should not be 1.2V or 0.9V but exactly 1V. It doesn't have to be 1.00001V but only 1.01 volt for example. It is enough. With that clarified. I just need a sine wave generator that can produce 1.8V (error of 1.801V) and 5000Hz (not 5001Hz or 4999 Hz). How do you build them anyway? Since I'd rarely use it. My budget for finished product (I want ot avoid building it) is lower to $50..

--- End quote ---

You are still very unclear regarding the accuracy you need (or want). So what is the voltage error you allow -- 0.01 V or 0.001 V? And what is the frequency error you allow -- less than 1 Hz, but how much can you tolerate? 0.1 Hz?

And you are very unclear regarding the budget. If it is $50, why did you tell us $200 before?

ebastler:
Here's an idea, if you are on a low budget: Keep your cheap generator, but buy a multimeter which lets you check its frequency and measure & adjust its output.

Most low-cost multimeters will not work for this, since their AC measurement capability is only specified up to 1 kHz or less. But e.g. the UNI-T UT61E is specified up to 10 kHz, hence should provide decent measurements for much of your desired audio range.

Its accuracy will be limited though; it's a bit better than 1% for AC voltage. [Edit: It's actually a tad worse than 1% when you go above 1 kHz.] Resolution will be much better. See the specifications for details.

bingo600:
For "purity" i have an old HP 3324A
Large , and might be a bit over your budget.

DS
https://accusrc.com/uploads/datasheets/6876_3324a.pdf

Nice options
https://www.ebay.com/itm/364625638885?


https://www.ebay.com/itm/364545127053?

Navigation

[0] Message Index

[#] Next page

[*] Previous page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod