I have wound a 110uH coil for an antenna system and I want to create a model of the inductor that I can use in a simulation program. In other words, I need to know the inductance, parasitic capacitance and ESR.
Using my NanoVNA-H4 I measured the inductance on a Smith chart at a low frequency (around 70kHz) where the reactance is about 50 ohms. I then measured the self resonant frequency (10.5MHz) and calculated the parasitic capacitance as 2pF.
Is that correct so far?
What about ESR? Is that the ohmic resistance of the coil or is it more complicated than that?
Thanks!
--
Mike
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Name format of the .cal files
Hi. Few questions:
1) I organized the name format of the .cal files stored in the microSD card of my NanoVNA-H4 as per the image in order to easily find them, as only capital letters can be used and dots / commas aren't available. How about you?
2 ) Have you tried to rename them with the PC in order to also use the lower case letters, commas, etc. (e g. 1.8MHz-29.7MHz.cal)? Did you get issues?
Many thanks.
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Thanks for all the help
I do have the smaller original VNA-H model
It does have a rechargeable battery. I charged it up and the unit turns on and there is software in it.
I'll purchase some SMA adapters to able to connect it to antennas.
I was watching videos on the wrong models and got confused.
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i have an extra battery from a smashed screen unit kicking around i could
drop it in an envelope for you if you like
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On Sat, Jun 24, 2023 at 5:49?PM Michael <m005kennedy@...> wrote: I bought one of these. I got the most inexpensive one. It says on the back
it is a VNA-H, it just covers the HF frequencies. I thought it would come
setup and ready to use.
Oops!
I thought it had a rechargeable battery, but doesn't look like it does.
So correct me if I'm wrong.
1 I need a battery pack to run it. 5 volts?
2 I need a SD card of 32 gigs.
3 I have to download the software for it.
4. Then I can figure out how to use it with online documentation.
Are these the correct steps? It is possible to get a card with the firmware
installed on it? I ask because I don¡¯t really have a good computer right
now, but I think I could probably borrow a laptop from the time it would
take to install it.
So will these head me in the correct direction ?
Mike
KB1IUI
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'Way back when the nanovna was new (about 4 years ago, I think), the cheapest ones came without battery - but mainly due to shipping restrictions in the originating country (hazardous material).
Did you look to see if there is a battery inside? The cheapest ones (like I bought then) do not have a case. You can see the circuit boards in it.
Plug yours into a USB connector or charger to give it power, and then see if it works.
--
Doug, K8RFT
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If it's a real -H, it should already have a rechargeable battery inside the
case, and you charge it with a USB cable.
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On Sat, Jun 24, 2023, 3:17 PM Jim Lux <jimlux@...> wrote: On 6/24/23 2:42 PM, Michael wrote:
I bought one of these. I got the most inexpensive one. It says on the back
it is a VNA-H, it just covers the HF frequencies. I thought it would come
setup and ready to use.
Oops!
I thought it had a rechargeable battery, but doesn't look like it does.
So correct me if I'm wrong.
1 I need a battery pack to run it. 5 volts? No, probably a standard 13650 battery - 3.5 volts.
2 I need a SD card of 32 gigs. Nope, not unless you want to save data and move it somewhere else.
3 I have to download the software for it. Only if you want to upgrade the existing firmware or use it with a PC.
Mine's 2-3 years old, and I'm running the original firmware.
4. Then I can figure out how to use it with online documentation.
Yes, and copious questions here.
Are these the correct steps? It is possible to get a card with the
firmware
installed on it? I ask because I don¡¯t really have a good computer right
now, but I think I could probably borrow a laptop from the time it would
take to install it. You don't load software from the SD card - that's just to store
measurements. If you want to upgrade the firmware, you'd do that from a
PC.
So will these head me in the correct direction ?
Mike
KB1IUI
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On 6/24/23 2:42 PM, Michael wrote: I bought one of these. I got the most inexpensive one. It says on the back
it is a VNA-H, it just covers the HF frequencies. I thought it would come
setup and ready to use.
Oops!
I thought it had a rechargeable battery, but doesn't look like it does.
So correct me if I'm wrong.
1 I need a battery pack to run it. 5 volts? No, probably a standard 13650 battery - 3.5 volts. 2 I need a SD card of 32 gigs. Nope, not unless you want to save data and move it somewhere else. 3 I have to download the software for it. Only if you want to upgrade the existing firmware or use it with a PC. Mine's 2-3 years old, and I'm running the original firmware. 4. Then I can figure out how to use it with online documentation. Yes, and copious questions here. Are these the correct steps? It is possible to get a card with the firmware
installed on it? I ask because I don¡¯t really have a good computer right
now, but I think I could probably borrow a laptop from the time it would
take to install it. You don't load software from the SD card - that's just to store measurements. If you want to upgrade the firmware, you'd do that from a PC. So will these head me in the correct direction ?
Mike
KB1IUI
|
I bought one of these. I got the most inexpensive one. It says on the back
it is a VNA-H, it just covers the HF frequencies. I thought it would come
setup and ready to use.
Oops!
I thought it had a rechargeable battery, but doesn't look like it does.
So correct me if I'm wrong.
1 I need a battery pack to run it. 5 volts?
2 I need a SD card of 32 gigs.
3 I have to download the software for it.
4. Then I can figure out how to use it with online documentation.
Are these the correct steps? It is possible to get a card with the firmware
installed on it? I ask because I don¡¯t really have a good computer right
now, but I think I could probably borrow a laptop from the time it would
take to install it.
So will these head me in the correct direction ?
Mike
KB1IUI
|
Unun means nothing. You should know that the nature Hello Francois,
What do you mean "UnUn" means nothing? It means unbalanced input
to unbalanced output. Many filters, band pass, high pass or low pass
are UnUn and many impedance matching networks are too.
** It is a French expression to indicate that there are a multitude of unbalanced / unbalanced impedance matching solutions. Already the expected transformation ratio will have major consequences. This transformation ratio only makes sense when considering non-reactive impedances. If a resonant antenna is purely resistive, in its bandwidth it is reactive. In a un/un, incorporating a toroid, the toroid can either be used as a choke or as the core of a transformer (or a bit of both). Don't believe that a un/un using a torus is a one-size-fits-all solution. Even if you use a (theoretical) perfect transformer between your antenna and the transmitter, you will need another device to compensate for impedance variations such as an ATU. That's why I wrote: "Unun means nothing" 73 -- F1AMM Fran?ois De la part de Kenneth Greenough Envoy¨¦ : vendredi 23 juin 2023 19:41
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I think that a few pictures of your fix would be of help to a lot of hams out there looking for cures to their problems.
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On 6/22/2023 8:55 AM, Steve wrote: Hello
I was having an issue with RFI in my shack, I'm in an apartment and my MFJ loop is at the back of the office next to a window and my radio is an Icom IC-7300. I made a CM choke from a 240-31 ferrite toroid core and it solved the problem on 40 and 20 meters. I was still having problems on 17 and 15 meters so I got a 240-43 donut and made a CM choke and it pretty well cleared up my problems aside from a couple of problem areas which were solved by a few more 240-43 ferrite toriod cores. I made up a test jig for my NanoVNA from articles found on the net. I could post a picture if anyone in interested
Steve ve4fx
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Excellent points Steve. (you get a Bravo-Zulu for that one)
Mike C. Sand Mtn GA
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On 6/23/2023 12:42 PM, Steve Johnson wrote: Garry says:
¡°¡ Then attach your inductor. ¡¡±
The devil is in the details with such a simple-sounding statement. Attach it how? There are 2 ports on the NanoVNA, each with a center conductor and an outside conductor (called, shield, ground, body, etc.) The inductor (DUT) has a single conductor with 2 ends. So, exactly how do you connect those 2 ends to the NanoVNA ports? Considering there is also an option of leaving certain ports, wire ends, or conductors (center/shield) disconnected, there are more than 10 possible options.
Then, once some sort of connection is made between inductor and VNA, which measurement option (menu choice) do you select on the NanoVNA? S11, S21, shunt, thru, etc. This decision adds more complexity.
For those experienced/ trained in using VNA¡¯s and deciding such things for multiple different types of DUT¡¯s, these may be such basic questions as to be assumed inherently obvious. But they are not inherently obvious to the new VNA users attracted to forums such as these.
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Fair-Rite has several excellent videos on measuring the yr of unknown toroids. Search their www site for videos. They are excellent. Dave - W0LEV On Fri, Jun 23, 2023 at 3:58?PM Roger Need via groups.io <sailtamarack= [email protected]> wrote: On Wed, Jun 21, 2023 at 12:48 PM, Kurt Heernaert wrote:
FT240-43 Torroid, Can I use my NanoVNA to meassure my several torroids
to be
sure that I have the correct ones for HF UNUN?
Measuring toroids has been discussed many times in this group over the
last few years. There is a wealth of information provided by many
knowledgeable group members. If you do a group message search on "toroid"
you will find lots on information on how to measure toroids and
identify/verify them using the NanoVNA. You can also take a look at this
groups wiki for links to relevant posts. How to use the S11 and S21
methods of impedance measurement and NanoVNA limitations with the S21
technique are discussed in depth. There is a wealth of information
provided by many knowledgeable group members.
Roger
-- *Dave - W?LEV* -- Dave - W?LEV
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On Wed, Jun 21, 2023 at 12:48 PM, Kurt Heernaert wrote:
FT240-43 Torroid, Can I use my NanoVNA to meassure my several torroids to be
sure that I have the correct ones for HF UNUN?
Measuring toroids has been discussed many times in this group over the last few years. There is a wealth of information provided by many knowledgeable group members. If you do a group message search on "toroid" you will find lots on information on how to measure toroids and identify/verify them using the NanoVNA. You can also take a look at this groups wiki for links to relevant posts. How to use the S11 and S21 methods of impedance measurement and NanoVNA limitations with the S21 technique are discussed in depth. There is a wealth of information provided by many knowledgeable group members. Roger
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On 23/06/2023 08:24, Fran?ois wrote: to be sure that I have the correct ones for HF UNUN?
any info is welcome Hello
Unun means nothing. You should know that the nature
Hello Francois, What do you mean "UnUn" means nothing?? It means unbalanced input to unbalanced output. Many filters, band pass, high pass or low pass are UnUn and many impedance matching networks are too. 73 Ken g8beq
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I should have also mentioned in detail how you measure things. Choose
"Display," then "Format S11 (Refl)." Looking down the list you will see
"Resistance" and "Reactance." Choose which you want to measure. You can do
further measurements by choosing "More" twice. In the choice of options,
you will see "Parallel R,' "Parallel X", "Parallel C" and "Parallel L."
(These are the best choices for measuring a single capacitor or inductor
connected as I described below. Note, the numbers of the reactance,
resistance and inductance vary with frequency and you would need to choose
an exact frequency by rocking the rocker arm back and forth to display the
values at one frequency.
Zack W9SZ
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On Fri, Jun 23, 2023 at 12:28?PM Zack Widup <w9sz.zack@...> wrote: I have some SMA right-angle connectors. The center pin of coax is supposed
to solder to the inner pin connection in the connector, and the shield is
crimped with a ferrule to the connector. But what I did was solder a wire
about 3 inches long to the inner pin connection and another wire to the
outer (ground) area of the SMA connector. This minimizes the capacitance
between the wires. (This is significant!) I measure 3.5 pF with my leads
and connector.
Make sure your NanoVNA is calibrated for the frequency range you want to
measure. Put the SMA connector on the s11 (top) port of the NanoVNA. Solder
the wires to the two leads of your inductor. You can then measure its
reactance, resistance and inductance with the appropriate measurement
settings of the NanoVNA.
I've done this with dozens, maybe hundreds of inductors,
Zack W9SZ
On Fri, Jun 23, 2023 at 11:42?AM Steve Johnson <cascadianroot@...>
wrote:
Garry says:
¡°¡ Then attach your inductor. ¡¡±
The devil is in the details with such a simple-sounding statement. Attach
it how? There are 2 ports on the NanoVNA, each with a center conductor and
an outside conductor (called, shield, ground, body, etc.) The inductor
(DUT) has a single conductor with 2 ends. So, exactly how do you connect
those 2 ends to the NanoVNA ports? Considering there is also an option of
leaving certain ports, wire ends, or conductors (center/shield)
disconnected, there are more than 10 possible options.
Then, once some sort of connection is made between inductor and VNA,
which measurement option (menu choice) do you select on the NanoVNA? S11,
S21, shunt, thru, etc. This decision adds more complexity.
For those experienced/ trained in using VNA¡¯s and deciding such things
for multiple different types of DUT¡¯s, these may be such basic questions as
to be assumed inherently obvious. But they are not inherently obvious to
the new VNA users attracted to forums such as these.
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I have some SMA right-angle connectors. The center pin of coax is supposed to solder to the inner pin connection in the connector, and the shield is crimped with a ferrule to the connector. But what I did was solder a wire about 3 inches long to the inner pin connection and another wire to the outer (ground) area of the SMA connector. This minimizes the capacitance between the wires. (This is significant!) I measure 3.5 pF with my leads and connector. Make sure your NanoVNA is calibrated for the frequency range you want to measure. Put the SMA connector on the s11 (top) port of the NanoVNA. Solder the wires to the two leads of your inductor. You can then measure its reactance, resistance and inductance with the appropriate measurement settings of the NanoVNA. I've done this with dozens, maybe hundreds of inductors, Zack W9SZ On Fri, Jun 23, 2023 at 11:42?AM Steve Johnson <cascadianroot@...> wrote: Garry says:
¡°¡ Then attach your inductor. ¡¡±
The devil is in the details with such a simple-sounding statement. Attach
it how? There are 2 ports on the NanoVNA, each with a center conductor and
an outside conductor (called, shield, ground, body, etc.) The inductor
(DUT) has a single conductor with 2 ends. So, exactly how do you connect
those 2 ends to the NanoVNA ports? Considering there is also an option of
leaving certain ports, wire ends, or conductors (center/shield)
disconnected, there are more than 10 possible options.
Then, once some sort of connection is made between inductor and VNA, which
measurement option (menu choice) do you select on the NanoVNA? S11, S21,
shunt, thru, etc. This decision adds more complexity.
For those experienced/ trained in using VNA¡¯s and deciding such things for
multiple different types of DUT¡¯s, these may be such basic questions as to
be assumed inherently obvious. But they are not inherently obvious to the
new VNA users attracted to forums such as these.
|
Garry says:
¡°¡ Then attach your inductor. ¡¡±
The devil is in the details with such a simple-sounding statement. Attach it how? There are 2 ports on the NanoVNA, each with a center conductor and an outside conductor (called, shield, ground, body, etc.) The inductor (DUT) has a single conductor with 2 ends. So, exactly how do you connect those 2 ends to the NanoVNA ports? Considering there is also an option of leaving certain ports, wire ends, or conductors (center/shield) disconnected, there are more than 10 possible options.
Then, once some sort of connection is made between inductor and VNA, which measurement option (menu choice) do you select on the NanoVNA? S11, S21, shunt, thru, etc. This decision adds more complexity.
For those experienced/ trained in using VNA¡¯s and deciding such things for multiple different types of DUT¡¯s, these may be such basic questions as to be assumed inherently obvious. But they are not inherently obvious to the new VNA users attracted to forums such as these.
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On 6/23/23 6:51 AM, Garry wrote: The different measurement techniques usually arise due to the propagation of error. In the case of vna's the measurement methods relate to the impedance of the DUT. You will find a number of articles online describing how to mak accurate measurements. One such article is
Basically, a 1-port measurement works best around the 50 ohm port impedance, shunt-through works best for low impedance, and series-through works best for higher impedance.
I believe the original question was more about "how do I figure out which mix this unmarked toroid is" and for that, measurement accuracy may not be super important, especially if you have some known examples to compare to. The nice thing about a VNA is you can easily sweep a wide frequency range, so you're looking for a "does my curve look more like curve A or curve B", rather than a single spot measurement at a single frequency and trying to figure out if your estimate of mu is correct. The what do R and X look like vs frequency is a pretty good way to distinguish materials. And if there's a measurement error it might not perturb that much. What you're really looking for is "not lossy at frequency range X but lossy at frequency range Y"
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The different measurement techniques usually arise due to the propagation of error. In the case of vna's the measurement methods relate to the impedance of the DUT. You will find a number of articles online describing how to mak accurate measurements. One such article is
Basically, a 1-port measurement works best around the 50 ohm port impedance, shunt-through works best for low impedance, and series-through works best for higher impedance.
I'm not sure that changing the measurement technique will help, unless you are experiencing significant errors. You might need to change your core size or even material to make inductors with less parallel capacitance and avoid self-resonance problems. I'm not an expert in filters, I have mostly built other people's designs and not a large number of them. But, it seems your problem may be the inductor construction.
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Andrea I2UEA
john rader
Mike C.
Roger Need