NanoVNA-H: bettering the post-mixer IF filter?
Hello! Would you recommend an LC-circuit as an IF filter? I'm looking into using one of [url=https://static.chipdip.ru/lib/261/DOC005261729.pdf]these[/url] SMD inductors (~hundreds of ¦ÌH) as a coil.
By
ZAO
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#16763
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Re: Phase of very high quality N short
@Dr. David Kirkby: Just like Dragan Milivojevic, I am also curious to hear what the flaws are in Larry Benko's videos. I actually find his videos very interesting and helpful. But I also understand
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Klaas
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#16762
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Re: #nanovna-h #applications #measurement #simulation
#nanovna-h
#applications
#measurement
#simulation
Folks, You can translate/convert PDF documents online at: https://www.onlinedoctranslator.com I translated the document to English and attached it. Enjoy! Larry
By
Larry Rothman
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#16761
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#nanovna-h #applications #measurement #simulation
#nanovna-h
#applications
#measurement
#simulation
Here is an application report on the NanoVNA-H and SPICE simulation. The report is in German. Enjoy!
By
oberschrat@...
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#16760
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Re: O S L on antenna side of a balun / choke with stud terminals?
If you want some encouragement read Kurt N. Sterba¡¯s articles from the Olde World Radio journal. It¡¯s free now. That¡¯s $0.00
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David Wilcox K8WPE
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#16759
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Re: O S L on antenna side of a balun / choke with stud terminals?
Antenna tuners cause any energy reflected from the antenna to turn around and head back out to the antenna again. So if the antenna is reflecting 1/4 of the energy back to the antenna tuner, after 2.5
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Jerry Gaffke
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#16758
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Re: O S L on antenna side of a balun / choke with stud terminals?
Jerry wrote: "...No, you can't just add transmission line length and get any purely resistive load looking into the transmission line that you might wish." I agree, having complex impedance involved
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Miro, N9LR
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#16757
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Re: O S L on antenna side of a balun / choke with stud terminals?
...I hit "reply" too soon... ... given: * short run of low loss t-line * no match between TX, t-line, antenna impedances * antenna tuner makes t-line/antenna appear to TX as TX's impedance (SWR at
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Miro, N9LR
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#16756
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Re: O S L on antenna side of a balun / choke with stud terminals?
So, based on what Dave and Jerry are pointing out, I have two VALID conclusions 1) Antenna tuners suck! They make t-line/antenna go gently on TX, but they hide what's behind them. Strive to have (at
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Miro, N9LR
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#16755
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Re: SWR trace always showing 1:1 as flat line at bottom of screen
after careful calibration the swr seems to be reading correctly with high values on the edges [email protected]> wrote:
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Edwin Michal
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#16754
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Re: O S L on antenna side of a balun / choke with stud terminals?
If you have at least a half wavelength of open wire ladder line, then the VSWR is equal to the maximum RF voltage you can measure across the ladder line divided the minimum RF voltage you can measure.
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Jerry Gaffke
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#16753
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Re: O S L on antenna side of a balun / choke with stud terminals?
To properly assess the SWR along any transmission line, one must measure BOTH current AND voltage at the same position along the line!! A voltage-only or a current-only measurement will indicate
By
W0LEV
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#16752
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Re: O S L on antenna side of a balun / choke with stud terminals?
It does get confusing when neither end is properly terminated to the characteristic impedance of the transmission line. You have reflections from both ends, and reflections of those reflection, until
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Jerry Gaffke
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#16751
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Re: We started selling SAA2 with N-type RF connector and 4-inch display
I had that problem too. I initially gave up but tried a day or two later ( maybe a different Aliexpress trader and got my town on the dropdown. I am waiting for imminent arrival. As far as working at
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Stephen Laurence
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#16750
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Re: Source for H4 Padded Storage Case?
Also you might want to check Harbor Freight. They have some really nice Pelican case clones and a small one that works quite well to hold the VNA and accessories. They are quite rugged for field work
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Sam Reaves
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#16749
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Re: Source for H4 Padded Storage Case?
You may have some luck with CaseLogic cases. They are very nice camers cases. They offer great protection. I have two with other things in them. K5MFP
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Michael Payne <michael.f.payne@...>
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#16748
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Re: We started selling SAA2 with N-type RF connector and 4-inch display
Ali Express insists on setting an address that it incorrect, it has a drop down list of cities and my place is not on the list so it did not work. Therefore I did not place an order. There are a lot
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Conrad, PA5Y
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#16747
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Re: Performance of my nanovna V2 clone - return loss of port 2 seems much too high ?
Mine (early amazon buy at 39$, that has internal shielding) meets 20db+ to its upper limit (900mhz). Since primary usage is less than 500mhz its adequate. If I need better I just put a 6DB pad ahead
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aparent1/kb1gmx <kb1gmx@...>
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#16746
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Re: O S L on antenna side of a balun / choke with stud terminals?
'm not sure I completely agree :) Fortunately (or unfortunately) the transmission line acts as a impedance transformer. Given the length of the transmission line, impedance "shown" on to the TX might
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Miro, N9LR
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#16745
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Re: O S L on antenna side of a balun / choke with stud terminals?
To directly answer you final question, SWR is the same throughout the length of a transmission line. Losses in the transmission line will make the SWR higher toward the antenna end, but usually not by
By
Jerry Gaffke
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#16744
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