Re: How find crystal filter terminaison resistor and capacitor
Hi again, and basic principle of the output impedance measurement. [image: image.png] Step 1. measure outpunt voltage V1 with no load (open circuit) Step 2 terminate ouput with the known resistor Step 3 Calculate Zout / Rout [image: image.png] 73 Predrag , 9a3qv On Mon, 8 Aug 2022 at 11:26, Predrag Pavo?evi? via groups.io <ppavosevic= [email protected]> wrote: Hi all,
this might be helpful.
[image: image.png]
[image: image.png]
R should be ~ 1 - 2 kOhm, noniductive.
73
Predrag, 9A3QV
On Mon, 8 Aug 2022 at 10:37, Arie Kleingeld PA3A <pa3a@...> wrote:
Thanks for this comment Gerard.
I upgraded to from DiSlord 1.1 to DiSlord 1.2.00 on an H4.3 and it seems
to work.
I tried 300 ohm as Zo and it moved the 50 ohm load to the place it
should be on a 300 ohm Smith Chart.
So far so good.
73
Arie PA3A
Op 8-8-2022 om 03:40 schreef John Gord via groups.io:
Gerard,
It looks like the latest H and H4 firmware from DiSlord also has the Port-Z rescaling.
--John Gord
On Sun, Aug 7, 2022 at 11:34 AM, John Gord wrote:
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Re: How find crystal filter terminaison resistor and capacitor
Hi all,
this might be helpful.
[image: image.png]
[image: image.png]
R should be ~ 1 - 2 kOhm, noniductive.
73
Predrag, 9A3QV
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On Mon, 8 Aug 2022 at 10:37, Arie Kleingeld PA3A <pa3a@...> wrote: Thanks for this comment Gerard.
I upgraded to from DiSlord 1.1 to DiSlord 1.2.00 on an H4.3 and it seems
to work.
I tried 300 ohm as Zo and it moved the 50 ohm load to the place it
should be on a 300 ohm Smith Chart.
So far so good.
73
Arie PA3A
Op 8-8-2022 om 03:40 schreef John Gord via groups.io:
Gerard,
It looks like the latest H and H4 firmware from DiSlord also has the Port-Z rescaling.
--John Gord
On Sun, Aug 7, 2022 at 11:34 AM, John Gord wrote:
|
Re: How find crystal filter terminaison resistor and capacitor
Thanks for this comment Gerard.
I upgraded to from DiSlord 1.1 to DiSlord 1.2.00 on an H4.3 and it seems to work.
I tried 300 ohm as Zo and it moved the 50 ohm load to the place it should be on a 300 ohm Smith Chart.
So far so good.
73
Arie PA3A
Op 8-8-2022 om 03:40 schreef John Gord via groups.io:
toggle quoted message
Show quoted text
Gerard,
It looks like the latest H and H4 firmware from DiSlord also has the Port-Z rescaling.
--John Gord
On Sun, Aug 7, 2022 at 11:34 AM, John Gord wrote:
|
Re: How find crystal filter terminaison resistor and capacitor
Gerard,
It looks like the latest H and H4 firmware from DiSlord also has the Port-Z rescaling.
--John Gord
toggle quoted message
Show quoted text
On Sun, Aug 7, 2022 at 11:34 AM, John Gord wrote:
Gerard,
In addition to the variable resistance fixture method, there is provision in
some firmware versions to mathematically modify the displayed data to show
what the response would be in a system with Z0 other than 50 ohms.
I think that this feature is available only for the V2 and later versions
because of the memory limitations in the original NanoVNA.
You can set Z0 to say, 330 ohms for typical 10.7 MHz ceramic filters. I don't
know how well this would work at 4kohm.
The DiSlord firmware has the Port-Z setting in the DISPLAY menu. The
ojisankoubou firmware has the Port-Z setting in the DISPLAY/SIMULATE menu.
--John Gord
On Sun, Aug 7, 2022 at 03:04 AM, Gerard wrote:
Hello,
I have a lot of 2 poles filters 20J26 Motorola and 45R15AZ.
I can¡¯t find the datasheet of these filters on the net, except on a site
that tells me that the 45R15AZ is a 3rd harmonic filter, but no datasheet.
So I have no value of termination resistance and capacity.
In addition, if you take a common model like a 45M15A, you find different
values depending on the manufacturer, it ranges from 560 Ohm/1pf to 4KOhm
-1pf.
My question is whether we can measure these values with a nanovna or some
other method.
and if you have the datasheet, put it.
Thank you
|
Re: How find crystal filter terminaison resistor and capacitor
Gerard,
In addition to the variable resistance fixture method, there is provision in some firmware versions to mathematically modify the displayed data to show what the response would be in a system with Z0 other than 50 ohms.
I think that this feature is available only for the V2 and later versions because of the memory limitations in the original NanoVNA.
You can set Z0 to say, 330 ohms for typical 10.7 MHz ceramic filters. I don't know how well this would work at 4kohm.
The DiSlord firmware has the Port-Z setting in the DISPLAY menu. The ojisankoubou firmware has the Port-Z setting in the DISPLAY/SIMULATE menu.
--John Gord
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Show quoted text
On Sun, Aug 7, 2022 at 03:04 AM, Gerard wrote:
Hello,
I have a lot of 2 poles filters 20J26 Motorola and 45R15AZ.
I can¡¯t find the datasheet of these filters on the net, except on a site
that tells me that the 45R15AZ is a 3rd harmonic filter, but no datasheet.
So I have no value of termination resistance and capacity.
In addition, if you take a common model like a 45M15A, you find different
values depending on the manufacturer, it ranges from 560 Ohm/1pf to 4KOhm
-1pf.
My question is whether we can measure these values with a nanovna or some
other method.
and if you have the datasheet, put it.
Thank you
|
Re: Smith's book. free download
You can create your own by printing or phocopying a blank chart onto A4 transparency film.- Michael (GW7BBY)
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On 06/08/2022 21:46, alan victor wrote: That book text site has a GOLDMINE of super books. Thanks for the link!
The Smith applications text comes with a dozen or so plastic overlays that are used in the text as a means of solving designs. You use a grease pencil.
Almost as munch fun as fooling with the vna. I have the originals and some where I stored away some clear plastic copies that I used in analog powerpoint
presentations!
Alan
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Re: Smith's book. free download
Interesting! I use PCmatic anti-virus and it's perfectly happy with that site?? Rudy N6LF
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Re: Smith's book. free download
Oops, 27 MB!
73,
Justin B.
KI5GKD
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Re: Smith's book. free download
TNX, just downloaded it. Pretty hefty PDF @ 21 MB!
Not sure I'll understand anything in it... :-\
73,
Justin B.
KI5GKD
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Re: Smith's book. free download
There are (were?) available plastic Smith charts with a rotatable outer scale and a slide-rule-like cursor, both pivoting on a rivet dead center on the chart. The cursor saved a lot of grease pencil plotting.
My copy of the book included erasable markers colored to match the various chart grids, to easier keep track of whether you were plotting impedances or admittances.
73, Don N2VGU
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Re: How find crystal filter terminaison resistor and capacitor
People seem to do it with variable resistors at input and output and tweak those untill the passband looks nice and flat.
Then the resistors can be measured with a multimeter to find out the impedance.
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How find crystal filter terminaison resistor and capacitor
Hello,
I have a lot of 2 poles filters 20J26 Motorola and 45R15AZ.
I can¡¯t find the datasheet of these filters on the net, except on a site that tells me that the 45R15AZ is a 3rd harmonic filter, but no datasheet.
So I have no value of termination resistance and capacity.
In addition, if you take a common model like a 45M15A, you find different values depending on the manufacturer, it ranges from 560 Ohm/1pf to 4KOhm -1pf.
My question is whether we can measure these values with a nanovna or some other method.
and if you have the datasheet, put it.
Thank you
|
Re: Smith's book. free download
Thank you! My browser wouldn't let me get it by clicking on the download button. But I was able to open it in pdf and then download.
Al, K2WM
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On 8/6/2022 12:52 PM, rseverns@... wrote: You can get a free copy of the second edition here:
Rudy N6LF
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Re: Smith's book. free download
That book text site has a GOLDMINE of super books. Thanks for the link!
The Smith applications text comes with a dozen or so plastic overlays that are used in the text as a means of solving designs. You use a grease pencil.
Almost as munch fun as fooling with the vna. I have the originals and some where I stored away some clear plastic copies that I used in analog powerpoint
presentations!
Alan
|
Re: Smith's book. free download
My Malwarebytes firewall blocked the above link, and claimed it was due to a Trojan; false positive perhaps???IMHO, With regard to the file size differences of the previous two links to copies. One copy of the book appears to?have been from a book which had been essentially scanned in page by page to create a pdf file. (The pages almost look?like a photocopy). The newer book appears to be a textualized copy of the original book converted to a pdf file.
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On Saturday, August 6, 2022 at 12:53:00 PM EDT, <rseverns@...> wrote:
You can get a free copy of the second edition here:
Rudy N6LF
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Re: Smith's book. free download
You can get a free copy of the second edition here:
Rudy N6LF
|
Re: Smith's book. free download
On 06/08/2022 17:14, Roy J. Tellason, Sr. wrote: Hm, 27MB as opposed to the 18.6MB from the link that I just posted, and the two sites appear to be*very* similar, if not identical. I wonder what the differences are in the files? Different editions of the book. David -- SatSignal Software - Quality software for you Web: Email: david-taylor@... Twitter: @gm8arv
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Re: Smith's book. free download
On Friday 05 August 2022 04:38:10 pm Larry McElhiney via groups.io wrote: Free PDF download here:
Just downloaded it.
Larry
AC9OX Hm, 27MB as opposed to the 18.6MB from the link that I just posted, and the two sites appear to be *very* similar, if not identical. I wonder what the differences are in the files? -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin
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Re: Smith's book. free download
On Friday 05 August 2022 03:34:22 pm Jim Lux wrote: "Electronic applications of the Smith Chart
in waveguide, circuit and component analysis"
Phillip H Smith
This it? -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin
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Re: NanaVNA H4 battery indicator shows full but unit powers off after a minute
If you look at a graph of voltage versus discharge time, you will see a knee where the voltage drops quickly just before the battery is fully depleted. If you want to test battery performance read my article QST May 2022 page 34.
Charge the battery and retry.. My battery lasts in excess of 45 minutes.
If you want to know more about batteries I recommend
Larry W8LM
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Arie Kleingeld PA3A
Donald S Brant Jr
Ismo V??n?nen OH2FTG
Gerard
David J Taylor
Larry Macionski