Re: Where does this noise/instability come from at and around 300MHz?
Disable calibration, set frequency range 280-300MHz
See frequency point there start this
Change THRESHOLD frequency to this (avaible in expert menu settings).
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Re: Simple Latest Firmware list available and links to download?
Hello! congratulations on your purchase! It is very interesting to look at the PCB of your NanoVNA v3. 5! If of course it does not bother you! Sincerely yours!
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New to NanoVna - Newest version?
Hello, I've been considering purchasing one of these for some time. I'm not an engineer or anything even close, but I am an amateur radio operator who enjoys experimenting with antennas, and this seems like a really useful tool. However, I am unsure of which model is most current. I understand that the latest is the NanoVna-H4, but none of the vendors listed on nanovna.con have this model in stock. It appears that Aursinc has the F version in stock on Amazon, I am not sure if there is much difference for my purposes, or if I should wait for the H4 to come back in stock. Also, is it safe to assume that the vendors listed through nanovna.com are selling good quality items? I'm a bit leery of buying a cheap clone from an unknown source.
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When I replace an outlet near a table or counter and downstream from a GFCI outlet in the kitch
ebay or amazon search forusb outlet wall
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On Tuesday, June 29, 2021, 9:37:48 PM EDT, Dave Merrill <r390a.urr@...> wrote: I repurpose old micro-USB cables and 5 V chargers with these USB-C adapters: Adding a sleeve of shrink tubing to cover the joint ensures they don't easily come apart. Dave N9ZC On Tue, Jun 29, 2021, 12:52 PM Jim Lux <jim@...> wrote: On 6/29/21 8:01 AM, Mikek wrote:
I pulled my NanoVNA-H out just to charge it, it has been a while since I used it. It powers up fine and the indicator says the battery is low.
I see the connector is not the usual micro USB on my phone, but is a USB-C. Did I get a charger with my unit, that I have lost?
I have no clue how I charger my Nano! I do have the 10" USB-C cable. I bought it from R&L.
? ? Thanks Guys
? ? Mikek Mine didn't have a charger but had a USB-C cable - you charge it using
any USB-C (or USB-A) charger.? I've used both: MacBook Pro which has
USB-C, but also has adapters to USB-A - I've also charged it from a
standalone charger.
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Short out the antenna to the coax ground, using a clip lead, then use the nano to locate the shorted antenna, or put a 50 ohm resistor across the coax, and look for a perfect match at most frequencies.
Or short out the coax end, and look for a short at the feedpoint, using an ohm meter.
73, and thanks,
Dave (NK7Z)
ARRL Volunteer Examiner
ARRL Technical Specialist, RFI
ARRL Asst. Director, NW Division, Technical Resources
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On 6/29/21 6:26 PM, Gary wrote: Hello Richard,
I have exactly the same problem here.? I have some twenty antennas in the attic.? The house is a 120 years old Victorian so the attic is huge.? We've owned it the last twenty-one years and I have coax running everywhere up there.? I too had labelled and charted everything initially but years of swapping this to that and that to another has resulted in total chaos..hi..hi.? I have a NanoVNA-F.? I am wondering just exactly how you went about using your Nano to identify each antenna?? Thanks.
73,
Gary - W6GVS
At 08:51 PM 6/29/2021, you wrote:
I purchased a NANOVNA-H some time ago to learn and hopefully solve a problem.? With an attic full of antennas that have all coax running to a box in the shack, I no longer knew which cable came from which antenna. Well labeled 25 years ago but four of the five are no longer readable. The Nano solved the problem along with some great guides from this group and nanovna-saver I have identified all four with their SWR patterns. TNX
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I repurpose old micro-USB cables and 5 V chargers with these USB-C adapters:
Adding a sleeve of shrink tubing to cover the joint ensures they don't
easily come apart.
Dave N9ZC
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On Tue, Jun 29, 2021, 12:52 PM Jim Lux <jim@...> wrote: On 6/29/21 8:01 AM, Mikek wrote:
I pulled my NanoVNA-H out just to charge it, it has been a while since I used it. It powers up fine and the indicator says the battery is low.
I see the connector is not the usual micro USB on my phone, but is a USB-C. Did I get a charger with my unit, that I have lost?
I have no clue how I charger my Nano! I do have the 10" USB-C cable. I bought it from R&L.
Thanks Guys
Mikek Mine didn't have a charger but had a USB-C cable - you charge it using
any USB-C (or USB-A) charger. I've used both: MacBook Pro which has
USB-C, but also has adapters to USB-A - I've also charged it from a
standalone charger.
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Good that you found it, although I should think that any USB-C cable should work. The simplest solution is perhaps to charge it from your computer. However that begins to get problematic if you are like many of us who have a growing collection of USB powered and connected devices. To that end I just purchased one of these: It seems to be of decent quality and so far works well. I have no affiliation with the seller or product, and over the last few days I have looked at a dizzying selection of interesting USB charging gadgets available now online. I have a somewhat different solution also on the way from NewEgg, we'll see how it works. 73 -Jim NU0C On Tue, 29 Jun 2021 08:36:40 -0700 "Mikek" <amdx@...> wrote: Thanks to all that responded.
I found the charging Cable I needed. It was a little deeper in the drawer than I expected.
Mikek
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Hello Richard,
I have exactly the same problem here. I have some twenty antennas in the attic. The house is a 120 years old Victorian so the attic is huge. We've owned it the last twenty-one years and I have coax running everywhere up there. I too had labelled and charted everything initially but years of swapping this to that and that to another has resulted in total chaos..hi..hi. I have a NanoVNA-F. I am wondering just exactly how you went about using your Nano to identify each antenna? Thanks.
73,
Gary - W6GVS
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At 08:51 PM 6/29/2021, you wrote: I purchased a NANOVNA-H some time ago to learn and hopefully solve a problem. With an attic full of antennas that have all coax running to a box in the shack, I no longer knew which cable came from which antenna. Well labeled 25 years ago but four of the five are no longer readable. The Nano solved the problem along with some great guides from this group and nanovna-saver I have identified all four with their SWR patterns. TNX
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I purchased a NANOVNA-H some time ago to learn and hopefully solve a problem. With an attic full of antennas that have all coax running to a box in the shack, I no longer knew which cable came from which antenna. Well labeled 25 years ago but four of the five are no longer readable. The Nano solved the problem along with some great guides from this group and nanovna-saver I have identified all four with their SWR patterns. TNX
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Re: RETURN LOSS thoughts de k3eui
Traditionally, the B in dB is capitalized because it someone's name.? Alexander Graham Bell. V, A, W, F, H, C etc are also capitalized because the units are named after people, Volta, Ampere, Watt, Faraday, Henry, Coulomb...
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On Tuesday, June 29, 2021, 8:35:10 AM MDT, Cliff <kd4gt.tn@...> wrote:
»å±ð³¦¡¤¾±¡¤²ú±ð±ô
noun
a unit used to measure the intensity of a sound or the power level of an electrical signal by comparing it with a given level on a logarithmic scale.
db is what I would call "unitless". It must always be referenced to some starting point. Sometimes we add a reference like dbm or dbW when talking about power.
Loss is a negative situation. Gain is positive. If I "loose" $20 gambling, I subtract 20 from what I had in my pocket at the start of the game. But going to basic algebra, if I subtract a negative number, I actually add [100 - (-20) = 120].
An amusing story from the TelCo industry: A station engineer had low levels coming into the transmitter from the studio over the phone line. He had the phone company tech there trying to fix the problem. The engineer asked the tech to turn up the gain on the circuit. The tech said he was not able to do that. After more discussion, the phone tech allowed that all he could do was to turn down the loss.
OK! Problem solved!
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On 6/29/21 8:01 AM, Mikek wrote: I pulled my NanoVNA-H out just to charge it, it has been a while since I used it. It powers up fine and the indicator says the battery is low.
I see the connector is not the usual micro USB on my phone, but is a USB-C. Did I get a charger with my unit, that I have lost?
I have no clue how I charger my Nano! I do have the 10" USB-C cable. I bought it from R&L.
Thanks Guys
Mikek Mine didn't have a charger but had a USB-C cable - you charge it using any USB-C (or USB-A) charger.? I've used both: MacBook Pro which has USB-C, but also has adapters to USB-A - I've also charged it from a standalone charger.
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Thanks to all that responded.
I found the charging Cable I needed. It was a little deeper in the drawer than I expected.
Mikek
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Did the unit come with that USB-A to USB-C cable?
Maybe I need to keep looking.
Mikek
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You can also plug the USB-A to USB-C cable into your computer USB
connector and connect the USB-C into the NanoVNA and it will charge.
*Clyde K. Spencer*
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On Tue, Jun 29, 2021 at 11:20 AM Clyde Spencer <cftr01b@...> wrote: Typically the NanoVNA does not ship with a charger, only the USB-A to
USB-C cable. You can charge the NanoVNA using a cell phone charger with a
USB-C connector. If you have the microUSB connector you can buy a microUSB
female to USB-C male adaptor.
*Clyde K. Spencer*
On Tue, Jun 29, 2021 at 11:02 AM Mikek <amdx@...> wrote:
I pulled my NanoVNA-H out just to charge it, it has been a while since I
used it. It powers up fine and the indicator says the battery is low.
I see the connector is not the usual micro USB on my phone, but is a
USB-C. Did I get a charger with my unit, that I have lost?
I have no clue how I charger my Nano! I do have the 10" USB-C cable. I
bought it from R&L.
Thanks Guys
Mikek
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Typically the NanoVNA does not ship with a charger, only the USB-A to USB-C
cable. You can charge the NanoVNA using a cell phone charger with a USB-C
connector. If you have the microUSB connector you can buy a microUSB female
to USB-C male adaptor.
*Clyde K. Spencer*
toggle quoted message
Show quoted text
On Tue, Jun 29, 2021 at 11:02 AM Mikek <amdx@...> wrote: I pulled my NanoVNA-H out just to charge it, it has been a while since I
used it. It powers up fine and the indicator says the battery is low.
I see the connector is not the usual micro USB on my phone, but is a
USB-C. Did I get a charger with my unit, that I have lost?
I have no clue how I charger my Nano! I do have the 10" USB-C cable. I
bought it from R&L.
Thanks Guys
Mikek
|
I pulled my NanoVNA-H out just to charge it, it has been a while since I used it. It powers up fine and the indicator says the battery is low.
I see the connector is not the usual micro USB on my phone, but is a USB-C. Did I get a charger with my unit, that I have lost?
I have no clue how I charger my Nano! I do have the 10" USB-C cable. I bought it from R&L.
Thanks Guys
Mikek
|
Re: RETURN LOSS thoughts de k3eui
»å±ð³¦¡¤¾±¡¤²ú±ð±ô
noun
a unit used to measure the intensity of a sound or the power level of an electrical signal by comparing it with a given level on a logarithmic scale.
db is what I would call "unitless". It must always be referenced to some starting point. Sometimes we add a reference like dbm or dbW when talking about power.
Loss is a negative situation. Gain is positive. If I "loose" $20 gambling, I subtract 20 from what I had in my pocket at the start of the game. But going to basic algebra, if I subtract a negative number, I actually add [100 - (-20) = 120].
An amusing story from the TelCo industry: A station engineer had low levels coming into the transmitter from the studio over the phone line. He had the phone company tech there trying to fix the problem. The engineer asked the tech to turn up the gain on the circuit. The tech said he was not able to do that. After more discussion, the phone tech allowed that all he could do was to turn down the loss.
OK! Problem solved!
|
Re: RETURN LOSS thoughts de k3eui
On Mon, 28 Jun 2021 at 17:43, Jim Lux <jim@...> wrote: On the other hand, if someone quotes a Return Loss as either positive or
negative, the *meaning* is generally understood, unless the circuit
returns more power than it receives (a ferrite circulator with an
amplifier, perhaps). So beating someone up for choosing the "other"
convention probably isn't worth it. If you're publishing a paper, or
better, writing a procurement spec or test procedure) - make sure it's
right. In the latter situations, I tend to not use the term return
loss, rather, I'd specify |S11| < -10 dB.
I would agree with this. There was a paper in an IEEE journal saying that the term return loss is used badly. As far as the author was concerned, a return loss of > 0 dB implied a gain - negative resistance amplifier or similar.This guy was an IEEE editor, so had the power to reject articles using the wrong units. I got along with his view, as a negative loss implies a gain. However, the IEEE,are not enforcing this now. If an antenna has a return loss of 15 dB, I say that's okay. If the same antenna has a return loss of -15 dB, I just accept that the author is using a different convention to what I find acceptable, but don't bother reporting it. What really pisses me off is that RadCom, the journal of the Radio Society of Great Britain, *often *has articles with the wrong units. Pressure is newton, forces in kg etc. This is a fairly regular occurrence, Some time ago I got contacted by a company offering to install solar cells on my property. I was not interested, but I played along as if I was. The guy kept referring to power in kW hr. I eventually spoke to his manager, who was just as dumb. Dr David Kirkby Ph.D C.Eng MIET Email: drkirkby@... Web: Kirkby Microwave Ltd (Tel 01621-680100 / +44 1621-680100) Stokes Hall Lodge, Burnham Rd, Chelmsford, Essex, CM3 6DT.
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Re: RETURN LOSS thoughts de k3eui
Here is the take away... The minute you say Return loss, everyone knows what it means...
73, and thanks,
Dave (NK7Z)
ARRL Volunteer Examiner
ARRL Technical Specialist, RFI
ARRL Asst. Director, NW Division, Technical Resources
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On 6/29/21 4:13 AM, Barry K3EUI wrote: TU all for such wonderful comments, all helping me to visualize the concept of RETURN measurement.
I think when we add the word return LOSS it bothers me.
A double-negative is always problematic: so RL = -20 dB ????
Is that the same as saying a GAIN of 20 dB?
I did make an error in saying RETURN LOSS is -20 dB.
That is not what I was thinking (but I did write it that way).
I am thinking the RETURN signal is 20dB weaker than the FORWARD signal.
And yes, the log (ratio) types of measures do not include the word "loss".
Maybe if I say my "hearing loss is 20 dB at 1000 Hz" that makes it clear.
I would not say my "hearing loss is -20 dB"
Again, the double-negative
Or, would I say my signal is -2 S units fainter than my neighbor's signal? No.
I am new to all of the VNA stuff. I've only had this Nano VNA tool for 10 months and have done a meager job of learning the fundamentals, and learning some really basic concepts that I should have mastered decades ago.
My background is in astrophysics and physics - not in engineering or electronics.
But I've been a ham since 1958 and should be more aware of the vocabulary, if not the meaning of the formulas involving logarithms.
Again - interesting discussion. It has helped me.
I will likely continue to plot the RETURN LOSS graphs with negtive values, but I will stop myself from saying a RETURN LOSS is a negative number.
I'm convinced now.
The other topic I am struggling to really grasp is when plotting the PHASE (S11) of say a dipole antenna, that when the reactance changes from negative to positive, at resonance, the graph is SO SO steep. That amazed me. The PHASE graph is much sharper than the SWR graph. But then the RETURN LOSS graph is also much sharper than the reflection coefficient (rho) graph.
Maybe that is why engineers like these graphs where the resonance and loss is so obvious.
As hams, I often measure SWR with a crude (cheap) meter.
Generally I don't fret if the SWR is 2:1 or less. My radio seems content with that.
I never realized that a gazillion different impedance values can result in the same SWR of 2:1
Or said another way, if I know the SWR, do I know the impedance? NO!!!!
When I see that now on a Smith Chart - say a circle with rho=0.33 I can see the RIM of that circle can represent many different R,X values - all with the same SWR of 2:1
Why is that not taught more clearly in ham radio study guides?
Maybe the thought is that a Smith Chart is way too complicated for rookies.
No. I think reading about the Smith Chart taught me the difference in SWR and impedance.
De k3eui Barry
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Re: RETURN LOSS thoughts de k3eui
TU all for such wonderful comments, all helping me to visualize the concept of RETURN measurement.
I think when we add the word return LOSS it bothers me.
A double-negative is always problematic: so RL = -20 dB ????
Is that the same as saying a GAIN of 20 dB?
I did make an error in saying RETURN LOSS is -20 dB.
That is not what I was thinking (but I did write it that way).
I am thinking the RETURN signal is 20dB weaker than the FORWARD signal.
And yes, the log (ratio) types of measures do not include the word "loss".
Maybe if I say my "hearing loss is 20 dB at 1000 Hz" that makes it clear.
I would not say my "hearing loss is -20 dB"
Again, the double-negative
Or, would I say my signal is -2 S units fainter than my neighbor's signal? No.
I am new to all of the VNA stuff. I've only had this Nano VNA tool for 10 months and have done a meager job of learning the fundamentals, and learning some really basic concepts that I should have mastered decades ago.
My background is in astrophysics and physics - not in engineering or electronics.
But I've been a ham since 1958 and should be more aware of the vocabulary, if not the meaning of the formulas involving logarithms.
Again - interesting discussion. It has helped me.
I will likely continue to plot the RETURN LOSS graphs with negtive values, but I will stop myself from saying a RETURN LOSS is a negative number.
I'm convinced now.
The other topic I am struggling to really grasp is when plotting the PHASE (S11) of say a dipole antenna, that when the reactance changes from negative to positive, at resonance, the graph is SO SO steep. That amazed me. The PHASE graph is much sharper than the SWR graph. But then the RETURN LOSS graph is also much sharper than the reflection coefficient (rho) graph.
Maybe that is why engineers like these graphs where the resonance and loss is so obvious.
As hams, I often measure SWR with a crude (cheap) meter.
Generally I don't fret if the SWR is 2:1 or less. My radio seems content with that.
I never realized that a gazillion different impedance values can result in the same SWR of 2:1
Or said another way, if I know the SWR, do I know the impedance? NO!!!!
When I see that now on a Smith Chart - say a circle with rho=0.33 I can see the RIM of that circle can represent many different R,X values - all with the same SWR of 2:1
Why is that not taught more clearly in ham radio study guides?
Maybe the thought is that a Smith Chart is way too complicated for rookies.
No. I think reading about the Smith Chart taught me the difference in SWR and impedance.
De k3eui Barry
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Dave Merrill
Jim Shorney
Richard Clemens
Lou W7HV
Dr. David Kirkby, Kirkby Microwave Ltd
Barry K3EUI