Method of equivalent circuit used on HP 4284A LCR meter
Dr. David Kirkby from Kirkby Microwave Ltd
There has been some discussion about the best way to represent data
measured as impedance, into an equivalent circuit. The most comprehensive
of these I have seen, which my company owns, is my obsolte HP 4284A
precision LCR meter.
which is *not* a VNA, but measures the impedance of a device using a 4-wire
Kelvin measurement. This means everything shown here could conceivably be
displayed.
Someone *might* want to implement all or a subset of these. *I'm not
suggesting they are all implemented - I am just listing them for possible
discussion. *I suspect my HP 4285A LCR meter (75 kHz to 30 MHz) does the
same, but I have not checked.
*HP 4284A 1 MHz LCR meter. *
Cp-D - a parallel capacitance Cp, with a dissipation fact D
Cp-Q - a parallel capacitance Cp, with a Q of Q
Cp-G - a parallel capacitance Cp, with a conductance G
Cp-B - a parallel capacitance Cp, with a susceptance B
Cp-Rp - a parallel combination of a capacitance Cp, and resistance Rp
Cs-D - a series capacitance Cs, with dissipation factor Q
Cs-Q - a series capacitance Cs, with a Q of Q
Cs-Rs - a series combination of capacitance Cs and resistance Rs
Lp-D - a parallel inductor, with a dissipation factor D
Lp-Q - a parallel inductor, with a Q of Q
Lp-G - a parallel inductor, with a conductance of G measured in siemens
Lp-Rp - a parallel combination of an inductance Lp and resistance Rp.
Ls-Q - a series inductor Ls, with a Q of Q
Ls-Rs - a series inductor Ls with resistance Rs
*R - X - I don't need to explain what that is. *
Z-theta (degrees) - The magnitude and phase of an impedance expressed in
degrees.
Z-theta (rad) - The magnitude and phase of an impedance expressed in
radians.
G-B - G is the conductance measured in siemens (admittance Y = G + j B)
Y-theta (degrees) the magnitude of the admittance Y, and phase angle
expressed in degrees
Y-theta (rad) the magnitude of the admittance Y, and phase angle expressed
in radians
--
Dr David Kirkby Ph.D C.Eng MIET
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, CHELMSFORD,
Essex, CM3 6DT, United Kingdom.
Registered in England and Wales as company number 08914892
Tel 01621-680100 / +44 1621-680100
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On Sun, Sep 29, 2019 at 06:21 PM, Gabriel Tenma White wrote:
Price will be around the same as the existing NanoVNA.
That might be interesting option. I expect a bigger screen is not really needed as you should be able to run from PC/Laptop anyway. I know some might want /P but that use might be in the minority. The design (H/W) will be open source? Given the history and user community already I would have thought that makes sense. 72 Dom M1KTA
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Re: How many hardware versions?
Reinier wrote:
The block diagram is missing the measurement of the reference signal?
----------------------------------------------------------------------------------------------------------------
Tidbits of info have been slow to trickle out. As Hugen's development team releases more details, you can be sure this group will get it out to its members.
Herb
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Re: Which Firmware Version?
Larry,
Where cam I find the DFU File Manager to convert the bin or hex file to dfu?
Mike N2MS
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-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Larry Rothman Sent: Thursday, October 3, 2019 3:03 PM To: [email protected]Subject: Re: [nanovna-users] Which Firmware Version? No problem. There are many names around for the same file.That is why I uploaded them in the files section and dated each one. Forum member ORISTO has created a WIKI page that describes the various releases: Firmware Versions (with links) by Oristo Po
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Rune,??
I checked with a friend who is very involved in such things.? I think 6db and 60 db are the normal points used for filter definitions.? For example, that is what Elecraft uses...
Mike WY6K
"... somewhere in the distance, there's a tower and a light, broadcastin' the resistance, through the rain and through the night..."
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On Thursday, October 3, 2019, 3:04:51 PM CDT, Rune Broberg <mihtjel@...> wrote: Mike, see attached for a first sneak peak of what I'm working on. I think I'm currently under-estimating the roll-off by measuring it from the -6dB point and to the end of the data. Is there a norm for how to do these measurements? Or should I just make it up as I go along? [image: image.png] -- Rune / 5Q5R On Thu, 3 Oct 2019 at 15:45, mike watts via Groups.Io <wy6k= [email protected]> wrote: Yes, all of those filter measurements would be useful for things I do.
Those functions would elevate you from "hero" to "demi-god" in my world.
:-)
Mike WY6K
"... somewhere in the distance, there's a tower and a light, broadcastin'
the resistance, through the rain and through the night..."
? ? On Thursday, October 3, 2019, 4:20:50 AM CDT, Rune Broberg <
mihtjel@...> wrote:
? Hi Norbert,
the application can run calibrations at far more than 401 points - I have
certainly done 5050 points at one point. ;-) But it does this in the
application, and not on the device, due to the hardware limitations.
I agree that a function to find cut-off frequencies for filters etc. would
be interesting, and I've put it on the list of features I would like to
implement for the next version, ie. for next week. I don't make any
promises though :-)
What measurements would be relevant to provide? Cut-off frequency, span for
band-pass, dB/octave and dB/decade fall-off, pass-band ripple?
--
Rune / 5Q5R
On Thu, 3 Oct 2019 at 11:12, <norbert.kohns@...> wrote:
Hi Rune,
thank you for fixing this issue!
I have a question for you in respect to the required number of data points
to measure a band pass filter. With 101 points it is most likely not
possible to find the -3 dB points because the sample point is way off from
-3 dB on both sides of the band pass. With 401 points it would work. An
automatic feature of measuring the bandwidth would be absolutely cool! The
TAPR software is able to perform a calibration at 401 points or even more
than that, so I am certain that you could do that as well.? I have no glue
on how difficult that would be, but more data points for calibration would
be a huge improvement.
Kind regards
Norbert, DG1KPN
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Size matters - with consumer electronics especially. It's just the old aged who have trouble with small screens (me included). The solution is simple, design it to be compatible with both small and large screens of the same number of pixels, or wear stronger glasses.
Mike
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Re: New mode R / L / C display
Agree this would be very helpful feature, particularly (asking for too much?) if it can support open or short zeroing to compensate for attachment mechanism (like the AADE LC measurement meter.)
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Really? Its length been frustrating me for a long time. I don't see other people putting it in and I don't think it's doing you any favours but you could at least try to get it on one line!
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Re: How many hardware versions?
From: Oristo Wiki now has a "Hardware Versions" link:
/g/nanovna-users/wiki
Perhaps the nanoVNA-F could be added? The document points to /g/nanovna-f================================ Thanks! Rather a pity that the two couldn't be combined. David -- SatSignal Software - Quality software for you Web: Email: david-taylor@... Twitter: @gm8arv
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Re: List of NanoVNA Console Commands
Nope - the WIKI page was created several weeks AFTER I created my document and it was out of date and lacking info when posted, so I added a link back to my document which I just updated today.
I don't know why the poster didn't just link to my document to begin with.
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On Friday, October 4, 2019, 5:23:21 a.m. GMT-4, hwalker <herbwalker2476@...> wrote: Jim, Larry pulled his original PDF document in favor of this link,? /g/nanovna-users/wiki/shellcommands . Herb
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Hello,
This email message is a notification to let you know that a file has been updated in the Files area of the [email protected]
group.
File: NanoVNA Console Commands Oct-4-19.pdf
Uploaded By:
Larry Rothman
Description:
This is the latest update of the Console Commands for the NanoVNA as of Oct 4th.
It replaces the previous version (9-5-25a).
Please let me know of any errors or omissions.
You can access this file at the URL:
/g/nanovna-users/files/NanoVNA%20Console%20Commands%20Oct-4-19.pdf
Cheers,
The Groups.io Team
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Re: Nano saver - Reading / Writing cal data
Hi Martin, that's a very interesting suggestion. I've put it on my backlog under "Future / Cool ideas" ;-) I *think* the firmware allows it. Probably. But I'm not entirely sure how to do it. Currently, I think I prefer to evolve the calibration methods I have put into application itself, as this already allows saving to a files, and loading whatever calibration is relevant for your measurement. It still lacks a number of features, and those will take priority at first. Thank you for making the suggestion, though! -- Rune / 5Q5R On Fri, 4 Oct 2019 at 15:28, Martin via Groups.Io <martin_ehrenfried= [email protected]> wrote: Hi Rune,
Would it be possible to use Saver as a mechanism to run the internal Nano
calibration routine, and save these plus any other settings, without having
to use the Nano interface. Then store the values to saver so that it's
possible to use Saver as a repository for the Nano values, even though
Saver doesn't use them itself ?
If it was then possible to download the values back into the Nano
memories, this would save considerable time and allow additional
configurations to be retained and quickly put back in to the Nano's limited
memories when required.
Regards,
Martin - G8JNJ
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Re: How many hardware versions?
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Re: New mode R / L / C display
Personally, I prefer Smith plot displayed at the same time,
over a span (e.g. 2:1) of application frequencies,
as a quick check that components are behaving "reasonably".
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Re: Cal-Kit Standards' Definitions
every user would need to compute a value for the delay,
which would be different for the value in the cal kit. If I correctly interpret Kurt, then with appropriate software: * attach an unterminated length of balanced transmission line * interactively dial that delay so that Smith plot does not spiral inward
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Nano saver - Reading / Writing cal data
Hi Rune,
Would it be possible to use Saver as a mechanism to run the internal Nano calibration routine, and save these plus any other settings, without having to use the Nano interface. Then store the values to saver so that it's possible to use Saver as a repository for the Nano values, even though Saver doesn't use them itself ?
If it was then possible to download the values back into the Nano memories, this would save considerable time and allow additional configurations to be retained and quickly put back in to the Nano's limited memories when required.
Regards,
Martin - G8JNJ
|
Hello,
This email message is a notification to let you know that a file has been uploaded to the Files area of the [email protected]
group.
File: NanoVNA Console Commands 9-5-25a.pdf
Uploaded By:
Larry Rothman
Description:
This is the latest update of the Console Commands for the NanoVNA.
Please let me know of any errors or omissions.
You can access this file at the URL:
/g/nanovna-users/files/NanoVNA%20Console%20Commands%209-5-25a.pdf
Cheers,
The Groups.io Team
|
Re: New mode R / L / C display
I think that that sort of feature - especially Q - would be really great.
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On Fri 4 Oct 2019, 14:20 Fred Piering, <fpiering@...> wrote: Martin:
That would be great if it can be done.
I have several RLC commercial meters, none going above 100KHZ, and they
all give similar but different answers.
Regards
Fred
WD9HNU
On 10/4/2019 8:44 AM, Martin via Groups.Io wrote:
Hi All,
I've been using my Nano quite extensively in the workshop, and I find it very handy for quickly checking the value of surface mount components,
particularly capacitors and inductors.
It would be really nice if it was possible to just display the RLC
values (and Q ?) in big text (no graph required) for a defined frequency
(or frequencies) so it could be used in place of a separate RLC meter, many
of which can only measure values at low frequencies <1MHz.
What do others think - would this be useful ?
Regards,
Martin - G8JNJ
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Re: New mode R / L / C display
Martin:
That would be great if it can be done.
I have several RLC commercial meters, none going above 100KHZ, and they all give similar but different answers.
Regards
Fred
WD9HNU
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On 10/4/2019 8:44 AM, Martin via Groups.Io wrote: Hi All,
I've been using my Nano quite extensively in the workshop, and I find it very handy for quickly checking the value of surface mount components, particularly capacitors and inductors.
It would be really nice if it was possible to just display the RLC values (and Q ?) in big text (no graph required) for a defined frequency (or frequencies) so it could be used in place of a separate RLC meter, many of which can only measure values at low frequencies <1MHz.
What do others think - would this be useful ?
Regards,
Martin - G8JNJ
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Re: Nano VNA - Useful frequency range
On Fri, Oct 4, 2019 at 01:59 PM, Rune Broberg wrote:
Hi Martin,
there are firmware versions that go to 1500MHz. The frequency limit does
nothing to limit the number of data points, and very, very little to limit
other features within the NanoVNA. It's just a few bytes of extra code :-)
So I don't think there are any merits to making more frequency limited
firmware versions.
Hi Rune, Ah OK, then I misunderstood the reasoning between about the various different frequency limits in the various versions of firmware. I was under the impression that the Nano's lower frequency limits were necessary as a trade to overcome other issues, but I'm pleased to hear that this is not the case. Just ignore my initial posting on the subject. Regards, Martin - G8JNJ
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WY6K Mike Watts
David J Taylor
Oristo
Fred Piering WD9HNU