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Reduce Frequency Range
#hacking
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On Fri, 13 Dec 2019 07:55:17 -0800, you wrote:
Is there any possibility of customizing the NanoVNA software for a lower frequency range? Let me guess: no, it cannot be done. Rather use MLS with your PC soundcard. (Maximum Length Sequence) There are expensive commercial sytems like CLIO. For a entry level system have a look here: It starts with 50 euros. OE8UWW |
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Probably, but you'd have to change the mixer coupling caps and the bridge circuit.? ?
??Here's your chance to play and let everyone know if it works!? Also, the output is a square wave so you'd need to deal with all sorts of harmonics or, instead you could mod the output to only send pink noise to the speakers and mix the return with the internal Freq source.? Sent from Rogers Yahoo Mail on Android On Fri, 13 Dec 2019 at 10:55 am, Webb, William<billwebb12@...> wrote: Is there any possibility of customizing the NanoVNA software for a lower frequency range? Yup, I wrote lower.? Aside from Ham radio HF applications, I would like to be able to characterize custom speaker crossovers.? The range would be, ideally, 20-20,000 Hz.? Can the hardware go that low? |
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It is a project, rather than an ebay buy, but
does a quality set of measurements from 10 Hz to 40 kHz. It is all open hardware and software. Note that at lower frequencies one can find impedance by directly measuring V and I (magnitude and phase) and calculating V/I. That is the usual method and is more accurate and simpler to do. There are also some very simple implementations of the impedance measurement part: G. R. Steber, WB9LVI, ¡°A Low Cost Automatic Impedance Bridge,¡± QST Oct. 2005, pp. 36?39. Also, ref 3 of the URL above. A side note is that the AVNA in the URL above is programmable from a serial link and prime for adaptation to the control software such as wonderful nanoVNA-saver. Anyone interested in doing that? I would be happy to support that with firmware changes to the AVNA, as needed. Bob W7PUA |
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A couple more notes. The reference 3 for Z measurement is in the QEX article
Also, there is a support group /g/AVNA1 Bob W7PUA |
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Bob Albert
It would be nice if someone would produce this unit for sale at a reasonable price.? An audio VNA would be great, as would be an audio SA.? I have use for the latter but it's not a common item.
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Bob K6DDX On Friday, December 13, 2019, 11:36:00 AM PST, Bob Larkin <bob@...> wrote:
It is a project, rather than an ebay buy, but does a quality set of measurements from 10 Hz to 40 kHz.? It is all open hardware and software. Note that at lower frequencies one can find impedance by directly measuring V and I (magnitude and phase) and calculating V/I.? That is the usual method and is more accurate and simpler to do. There are also some very simple implementations of the impedance measurement part: G. R. Steber, WB9LVI, ¡°A Low Cost Automatic Impedance Bridge,¡± QST Oct. 2005, pp. 36?39.? Also, ref 3 of the URL above. A side note is that the AVNA in the URL above is programmable from a serial link and prime for adaptation to the control software such as wonderful nanoVNA-saver.? Anyone interested in doing that?? I would be happy to support that with firmware changes to the AVNA, as needed. Bob? W7PUA |
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There are various free PC applications that use the sound card for an audio spectrum analyzer.? If you use a good quality sound card (flat response, low noise level) I would think that the results would be pretty good.? The sensitivity is typically good enough that there are even VLF receiver applications out there.
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73, Dave?? AB7E On 12/13/2019 12:56 PM, Bob Albert via Groups.Io wrote:
An audio VNA would be great, as would be an audio SA.? I have use for the latter but it's not a common item. |
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Bob Albert
I will have to look around; do you have a link to a specific audio SA?? Basically I want it to measure distortion of an audtio oscillator.
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Bob On Friday, December 13, 2019, 01:52:57 PM PST, stone_ridge_road <xdavid@...> wrote:
There are various free PC applications that use the sound card for an audio spectrum analyzer.? If you use a good quality sound card (flat response, low noise level) I would think that the results would be pretty good.? The sensitivity is typically good enough that there are even VLF receiver applications out there. 73, Dave?? AB7E On 12/13/2019 12:56 PM, Bob Albert via Groups.Io wrote: An audio VNA would be great, as would be an audio SA.? I have use for the latter but it's not a common item. |
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The applications (I've used more than one) that I've used in the past are pretty old by now, so I found this supposedly more recent list of free applications:
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However, this one looks pretty powerful and the standard version is only $30 US dollars if you buy it before December 15. 73, Dave?? AB7E On 12/13/2019 3:15 PM, Bob Albert via Groups.Io wrote:
I will have to look around; do you have a link to a specific audio SA?? Basically I want it to measure distortion of an audtio oscillator. |
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Don't forget about the free Android audio spectrum analyzer apps you can run on your phone or tablet.?
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They might even run on Chrome under arcwelder.? On Fri, 13 Dec 2019 at 5:16 PM, Bob Albert via Groups.Io<bob91343@...> wrote: I will have to look around; do you have a link to a specific audio SA?? Basically I want it to measure distortion of an audtio oscillator. Bob On Friday, December 13, 2019, 01:52:57 PM PST, stone_ridge_road <xdavid@...> wrote:
There are various free PC applications that use the sound card for an audio spectrum analyzer.? If you use a good quality sound card (flat response, low noise level) I would think that the results would be pretty good.? The sensitivity is typically good enough that there are even VLF receiver applications out there. 73, Dave?? AB7E On 12/13/2019 12:56 PM, Bob Albert via Groups.Io wrote: An audio VNA would be great, as would be an audio SA.? I have use for the latter but it's not a common item. |
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DL4YHF's "Spectrum Lab" (sound card data handler and spectrum analyzer)
looks a bit overwhelming at first, but it is really not that hard to use. It is very well done with very powerful control and post processing and, importantly, is well supported by the author. I have used it a lot, as have many others. Bob W7PUA |
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