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Re: NanoVNA with bigger screen
Hi Robert,
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I have tried several times to send a message to cqxiegu, but I never got an answer. I can't understand how a company like Xiegu can not respond to customer inquiries. Other hams have contacted me who have had a similar problem to mine and have gone through an odyssey to get it fixed. I hope I won't be forced to buy an icom 705, especially to avoid arguing with my wife....hi Thanks and 73 Maurizio IW2GOB Il 28/06/2023 15:58, Siegfried Jackstien ha scritto:
nanovna v2plus4, lite vna64, nanovna h4, nanovna -F V2, etc etc |
Re: S11 ? if Zc complexe
Everitt and Anner, "Communication Engineering," Third Edition, McGraw-Hill, 1956, provide a general method (pages 330-331) for examining a mismatch between a source and load, such as a transmission line feeding an antenna. They factor the source and the load into series networks, one element of which in each case is Zo, the desired impedance.
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They then use "Compensation Theorem A" from page 107, which states": "Any impedance in a network (either linear or nonlinear) may be replaced by a generator of zero internal impedance, whose generated voltage at every instant is equal to the instantaneous potential difference produced across the replaced impedance by the current flowing through it." Using this theorem, they replace the added network segments by voltage generators so that the resultant equivalent network consists of a matched source and load with added voltage generators to represent the voltages generated by the mismatch. I applied this to the special case of the complex conjugate load in "More Octave for Complex Zo," QEX, September/October, 2019. In that case, no modification of the source voltage or impedance is needed and the complex conjugate load is replaced by a matched load (image impedance) in series with a reactance of opposite sign that is twice the value of the reactance of the complex conjugate load's reactance. That "extra" reactance may then be replaced by a complex voltage source of zero internal impedance that will be seen to be generating a voltage that corresponds to the value of the reflected signal. 73, Maynard W6PAP On 6/26/23 23:01, Fran?ois wrote:
That's it, we have converged. In my application where I am looking for an equality between a value obtained by scanning and a target value, the distance between between the two points (in the complex plane) is a much better criterion for a good result than the ROS which only complicates by creating a non-monotonic function. |
Re: NanoVNA with bigger screen
nanovna v2plus4, lite vna64, nanovna h4, nanovna -F V2, etc etc
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there are a handful of vna and vna v2 with 4 inch or 4.3 inch screens i recommend to use one of the newer v2 models that go up to 3 or even up to 6 ghz cause the older models (1.5ghz) only have a clock up to 300mhz and above that (900mhz or 1.5ghz) is measured in harmonic mode (with reduced sensitivity and dynamic range) ... the newer v2 models are much better on the higher frequency area maybe a lite64 is for you?? or a plus4 or ... a vna6000??? (a bit expensive in my view) greetz sigi dg9bfc ps an option is to buy a cheaper version and add a 4 inch screen to it ... just needs the fw for that bigger screen to be uploaded in the device Am 28.06.2023 um 04:45 schrieb Pedro Madeira CT7AHV: Hello to all |
Re: NanoVNA with bigger screen
On 28/06/2023 03:45, Pedro Madeira CT7AHV wrote:
Hello to allPedro, There are several, but the "LiteVNA 64" has coverage up to 6 GHz and gets good reviews and comments here. If 2 GHz is enough try the NanoVNA H4 Beware of clones.... 73, David GM8ARV -- SatSignal Software - Quality software for you Web: Email: david-taylor@... Twitter: @gm8arv |
Re: NanoVNA with bigger screen
Pedro,
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most probably it was an nanoVNA-H4 (/g/nanovna-users/wiki#NanoVNA-H4) There are other possibilities, but they are more expensive. HTH, 73, Stay Safe, Robin, G8DQX On 28/06/2023 03:45, Pedro Madeira CT7AHV wrote:
Hello to all |
Re: Inductor model
On Tue, Jun 27, 2023 at 05:54 AM, Mike wrote:
I compared both methods of calibration, which I refer to as "screws" andWith a 110 uH coil it takes 4.2 pF to resonate at 7.4 MHz. and 1.4 pF to resonate at 12.9 MHz. That is a difference of 2.8 pF which is not much. One way to get to the bottom of this is to short the terminals of the coil together and then "grid dip" it like the old days. You can do this with the NanoVNA by making a pickup coil at the end of a short connecting cable. Calibrate over 5 to 15 MHz. in the usual manner. Set the trace to S11 Log (Return Loss setting) Then attach the pickup coil to the NanoVNA and place the 110 uh coil and the pickup coil in parallel a short distance apart. Look for a dip in the trace. Keep moving the coil further away until the dip has just about disappeared. Now move a marker to the dip and the frequency should be very close to the SRF. Roger |
Re: Transmission Line Tools
On Tue, Jun 27, 2023 at 04:23 PM, Robert wrote:
I have a PC with Windows 7 Pro SP1 32bit (German).My batch file is for 64 bit systems only. Try manually copying TeeChart5.ocx to C:\WINDOWS\system32 Then run TLW3.exe Roger |
Re: Transmission Line Tools
Hello Roger,
I have a PC with Windows 7 Pro SP1 32bit (German). C:\windows\SysWOW64 does not exist on my OS, and your batch file reports an error. On my 2 other Win10 64bit PCs TLW3 works ok after running TLW3-Install.bat. I get the Error 339 when I exit TLW3. Help is much appreciated. 73, Robert W4BCZ |
Re: Inductor model
What I wanted to do is not working.
I have an Excel sheet that allows me from the S11 of an antenna to determine its L and C near the resonance by pressing the curve of a plug to pass through two points. In your case, it works at resonance but we already know the values involved. Far from resonance the results are not good. -- Fran?ois De la part de Mike Envoy¨¦ : mardi 27 juin 2023 15:00 |
Re: Inductor model
On Tue, Jun 27, 2023 at 09:02 AM, Fran?ois wrote:
Hi Fran?ois Here is the .s1p file for a range of 1 to 20MHz. -- Mike G8GYW |
Re: Inductor model
On Mon, Jun 26, 2023 at 05:25 PM, Roger Need wrote:
I suggest you calibrate right at the screw terminations on the green blockRoger I compared both methods of calibration, which I refer to as "screws" and "crocs". At around 72kHz, where the reactance is approximately 50R, both calibration methods give an inductance of 108uH. However, the SRF was 7.4MHz for "screws" and 12.9MHz for "crocs". I then repeated the measurement with a different VNA, an FA-VA5. This gave L=110.7uH for "screws" and 110.5uH for "crocs". The SRF was 6.38MHz for "screws" and 6.45MHz for "crocs". I can accept the difference in L between the two devices but can't decide which one is giving me the most accurate SRF. -- Mike |
Re: nanovna-saver crashes with H4
That is a very old version of NanoVNA Saver, download the latest
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version and try again. On Mon, 26 Jun 2023 at 23:07, Fred Moore <n40cla@...> wrote:
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Re: Inductor model
Could you post your .s1p file in shunt on port 0. I would like to reger something.
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Have you noticed that when you connect a coil or a trap (finally a dipole) by a single leg on port 0 (the other leg in the air), looking at the ROS, you can see the resonance very well. Ok, it only gives elements at the resonance frequency... but still it's very practical 73 -- F1AMM Fran?ois -----Message d'origine-----De la part de Mike Envoy¨¦ : lundi 26 juin 2023 10:23 |
Re: Outliers in group delay measurement
Here it is, thanks for taking a minute to look into it.Attachments : - your smoothed file - the processing log (.CSV) showing the anomalies detected. - the S21 Group Delay (ns) on the smoothed file 73 -- F1AMM Fran?ois De la part de astech119 Envoy¨¦ : lundi 26 juin 2023 20:24 230621-60in01-1MHz-701MHz-1212pts-NVNA1X.s2p
230621-60in01-1MHz-701MHz-1212pts-NVNA1X.s2p
SmoothVNA.log.csv
SmoothVNA.log.csv
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230621-60in01-1MHz-701MHz-1212pts-NVNA1X.png
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Re: S11 ? if Zc complexe
That's it, we have converged. In my application where I am looking for an equality between a value obtained by scanning and a target value, the distance between between the two points (in the complex plane) is a much better criterion for a good result than the ROS which only complicates by creating a non-monotonic function.
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When the result of the calculation is equal to the target, the ROS is indeed ONE and the distance zero. It is in the search for the optimal that the ROS disrupts everything. -- F1AMM Fran?ois -----Message d'origine-----De la part de Maynard Wright, P. E., W6PAP Envoy¨¦ : mardi 27 juin 2023 00:56 |
Re: nanovna-saver crashes with H4
Thanks for the info. I do NOT use usc-c to usb-c cables. I use the
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standard original usb-a to usb-c. Can you provide a link for the latest DiSLord code? Thanks Fred On Mon, Jun 26, 2023 at 7:57?PM Stan Dye <standye@...> wrote:
I had a similar problem when I had a bad cable or a bad port connection. |
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