Re: NanoVNA-H4 Calibration Loads
You have been busy behind the scenes :)
So those of us that ordered the H4 in the last
month should use VNA2 coefficients?
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On Mon, 14 Dec 2020 at 02:47, Hugen <hugen@...> wrote: On Sun, Dec 13, 2020 at 01:05 PM, Dragan Milivojevic wrote:
Ask Kurt to characterize these?
On Sun, 13 Dec 2020 at 05:33, Hugen <hugen@...> wrote:
On Sun, Dec 13, 2020 at 10:19 AM, Roger Need wrote:
50.78 ohms
The load attached to the H4 has been re-matched to perform better at
higher frequencies. The 49.9 ohm load used earlier performed quite
badly
above 2GHz, but the new and improved load can get S11 below -30dB at
6GHz.
For measurements that require higher frequencies, the new load better.
For
UHF measurement, I suggest you use the load included with H4 for
calibration.
This is the test report provided by Kurt after I provided H4 OSL
accessories and 6GHz VNA to Kurt. It can be seen that the effects of OSL
accessories within 6GHz are satisfactory.
The test information provided in the attachment, OSL is the same as H4, FF
thru has been redesigned and will be provided with our future products.
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Re: NanoVNA-H4 Calibration Loads
On Sun, Dec 13, 2020 at 01:05 PM, Dragan Milivojevic wrote:
Ask Kurt to characterize these?
On Sun, 13 Dec 2020 at 05:33, Hugen <hugen@...> wrote:
On Sun, Dec 13, 2020 at 10:19 AM, Roger Need wrote:
50.78 ohms
The load attached to the H4 has been re-matched to perform better at
higher frequencies. The 49.9 ohm load used earlier performed quite badly
above 2GHz, but the new and improved load can get S11 below -30dB at 6GHz.
For measurements that require higher frequencies, the new load better. For
UHF measurement, I suggest you use the load included with H4 for
calibration.
This is the test report provided by Kurt after I provided H4 OSL accessories and 6GHz VNA to Kurt. It can be seen that the effects of OSL accessories within 6GHz are satisfactory. The test information provided in the attachment, OSL is the same as H4, FF thru has been redesigned and will be provided with our future products.
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Re: NanoVNA-H4 Calibration Loads
Looking through the old messages I see a post by Alan Wolke (W2AEW) where he recommends a low-cost Mini Circuits ANNE-50L+ SMA termination as a 50 ohm cal load replacement for the one provided with the NanoVNA-H4. /g/nanovna-users/message/14199The specifications are very good for the ANNE-50L+. The Return Loss (RL) near DC is 55 dB which is a DC resistance of 49.85 ohms compared to the one that came with my unit which measures 50.78 ohms and a RL of 42 db at low frequencies. The ANNE-50L+ RL slowly gets worse as the frequency is increased but even at 1.5 GHz (max for -H4 with factory firmware) it is 42 dB. My interests are with HF and UHF/VHF where the RL is no worse than 50 dB. There is a belief that low frequency RL performance is a trade-off with high GHz performance. To some degree this is true as you can see in the RL vs frequency plots I attached for the mini Circuits Anne series of terminators. From the previous thread on this subject some felt that there was no need to be concerned about RL to this degree and the supplied cal kit is satisfactory. That is true if all one is interested in is measuring/tuning antennas for VSWR and to get a rough idea of impedance. But some of us, like me, are mainly concerned with measuring components, filters, baluns, circuit S parameters etc. and we are trying to get the best performance possible from our NanoVNA. I am amazed how accurate the NanoVNA devices can be with proper attention to calibration and test fixture construction. Roger
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Gud to hear, Junior. John VE7KKQ On Sun, Dec 13, 2020 at 2:42 AM J¨²nior PY2ADA via groups.io <aaj280174= [email protected]> wrote: The nanovna returned to work
I reflow the board and everything is normal now
Calibrated and reading my antennas
Thank you all for your help
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Re: Reading PHASE measurements on an 80m dipole with NANO VNA SAVER
Hallo Barry,
looking at the phase plot you see the phase of the complex reflection faktor and not the phase of impedance Z. Having a perfect match at a certain frequency, the reflection factor is going to 0 and the phase of it can not be determind. As you can see from smith chart, the curve, coming from lower frequencies, hit the center of the chart nearly in a right angel to the real axis. In the phase chart you can see this behavior in a jump of phase from -180¡ã to +180¡ã.
73, Guenter, dk5dn
Am 13.12.2020 um 15:45 schrieb Barry Feierman:
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Looking at the PHASE data on a single band 80m center fed dipole.
See the two attachments: one without antenna tuner, one with an antenna tunder
I've had so much fun and have learned so much about antenna parameters with this little Nano VNA device.
One of the parameters that I was not familiar with is to look at the PHASE data, say on an 80m dipole: a 130 ft long center-fed dipole with about 150 feet of low-loss RG213 50-ohm coax.
The antenna on 80m had a natural resonance around 3580 kHz (where I like to operate digi modes on NBEMS nets).
Remember at resonance, the reactance is zero (regardless of the SWR). The PHASE is zero degrees.
But that antenna had an awful SWR at the top of the band, where the phone nets play around 3990 kHz.
At 3990 kHz, the SWR was more like 4:1 and my rig was not happy.
So, how do I QSY to the top of the band with decent SWR without cutting 10 feet off my dipole?
Well, with an antenna "tuner" in the shack, I can null out the reactance of the antenna at 3990 kHz, and get an almost 1:1 SWR on the coax going to the transmitter.
My rig is "happy" at 3990 kHz with that low SWR. But the SWR is still 4:1 on my feed line.
The SWR is only reduced on the coax between the tuner and the rig.
How would a PHASE plot look for my antenna AFTER the RF passes thru my antenna tuner (T network)?
Well, a PHASE plot shows me the original resonance of the 80m dipole around 3600 kHz (without the tuner) and the SWR and RETURN LOSS graphs verify this as well. Now, post antenna tuner, matched to the TOP of the 75m band, there is a second NEW resonance at around 3900 kHz post antenna tuner. Thus, the tuner RE-REFLECTS the reflected wave at 3900 kHz back in the direction of the antenna. Something W2DU Walt Maxwell claimed was how it worked.
Fascinating stuff. The tuner (in my shack) provides a "conjugate" impedance to offset the reactance at the feed line/antenna boundary. Thus an impedance of R + jX (in my shack) combines with an impedance of R - jX in the tuner ==> resulting in an impedance of R + j0 for the radio, with R about 50 ohms. Beautiful.
And, my low-loss RG213 feed line at 4 MHz, even with a 4:1 SWR, has less than a 1 dB "loss" due to the 4:1 SWR.
A 1 dB loss is barely noticeable.
So why worry about broad-band 80m antennas (gazillion articles in QST)?
Just put a decent tuner in your shack and QSY where you want with very little attenuation in low-loss cable (on 80m).
There is also very little "loss" in the tuner itself with decent size inductors and capacitors.
So cool to see all of this concept verified on the NANO VNA PHASE plot using VNA SAVER software (Win 10).
de Barry k3eui
Phila
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Re: Setting up NanoVNA-H for First Use
Can you add renaming the slots?
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On Dec 9, 2020, at 9:48 PM, DiSlord <dislordlive@...> wrote:
Settings for Freq range, trace count, scale and so on, stored to calibration slot after calibration, and load after load from it.
Also you can change setting, and store to slot. Calibrate->Save>Slot N
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Reading PHASE measurements on an 80m dipole with NANO VNA SAVER
Looking at the PHASE data on a single band 80m center fed dipole.
See the two attachments: one without antenna tuner, one with an antenna tunder
I've had so much fun and have learned so much about antenna parameters with this little Nano VNA device.
One of the parameters that I was not familiar with is to look at the PHASE data, say on an 80m dipole: a 130 ft long center-fed dipole with about 150 feet of low-loss RG213 50-ohm coax.
The antenna on 80m had a natural resonance around 3580 kHz (where I like to operate digi modes on NBEMS nets).
Remember at resonance, the reactance is zero (regardless of the SWR). The PHASE is zero degrees.
But that antenna had an awful SWR at the top of the band, where the phone nets play around 3990 kHz.
At 3990 kHz, the SWR was more like 4:1 and my rig was not happy.
So, how do I QSY to the top of the band with decent SWR without cutting 10 feet off my dipole?
Well, with an antenna "tuner" in the shack, I can null out the reactance of the antenna at 3990 kHz, and get an almost 1:1 SWR on the coax going to the transmitter.
My rig is "happy" at 3990 kHz with that low SWR. But the SWR is still 4:1 on my feed line.
The SWR is only reduced on the coax between the tuner and the rig.
How would a PHASE plot look for my antenna AFTER the RF passes thru my antenna tuner (T network)?
Well, a PHASE plot shows me the original resonance of the 80m dipole around 3600 kHz (without the tuner) and the SWR and RETURN LOSS graphs verify this as well. Now, post antenna tuner, matched to the TOP of the 75m band, there is a second NEW resonance at around 3900 kHz post antenna tuner. Thus, the tuner RE-REFLECTS the reflected wave at 3900 kHz back in the direction of the antenna. Something W2DU Walt Maxwell claimed was how it worked.
Fascinating stuff. The tuner (in my shack) provides a "conjugate" impedance to offset the reactance at the feed line/antenna boundary. Thus an impedance of R + jX (in my shack) combines with an impedance of R - jX in the tuner ==> resulting in an impedance of R + j0 for the radio, with R about 50 ohms. Beautiful.
And, my low-loss RG213 feed line at 4 MHz, even with a 4:1 SWR, has less than a 1 dB "loss" due to the 4:1 SWR.
A 1 dB loss is barely noticeable.
So why worry about broad-band 80m antennas (gazillion articles in QST)?
Just put a decent tuner in your shack and QSY where you want with very little attenuation in low-loss cable (on 80m).
There is also very little "loss" in the tuner itself with decent size inductors and capacitors.
So cool to see all of this concept verified on the NANO VNA PHASE plot using VNA SAVER software (Win 10).
de Barry k3eui
Phila
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Re: NanoVNA-H4 Calibration Loads
This seems to be true for the V2 Plus4 version, supplied a 50.931 ohm cal load and I was told by OEM is to improve the HF Return Loss. Also did confirm that using a cal load closer to 50 ohms does improve the LF measurements with the V2 Plus4.
Best,
--
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike
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Re: MiniVNA vs NanoVNA Balun Test plot query
Roger,
Thank you for your feedback, notes and links. If I had does electronic engineering or studies in significant depth and worked in the field then I suspect that alternate terms used for the same thing may be less of an issue than they seem to be when you come back to something after years away from it and are grappling with things. I agree wholeheartedly with your comments regarding baluns, being apparently simple, but then gravity was simple ... things, simply fell to the ground until we got into Newtonian meaurements HI.
I have spent some time working on things and and with some help making up an addon test rig arrangement so that I can test S11 VSWR impact of the choke and S21 common Mode rejection but as yet I am waiting for some bits to arrive so I can connect each pairing between the center feeds of the CH0 and CH1 SMA conectors to plot that. I probably only need to check one pairing but I may as well check both match.
Ross,
Thank you too.
I like the signature..... Bite off ... and Chew like.... Well I am trying to do this in a way that is postive.
Both and to Dave Daniel
I doubt I'll post much on in the group if at all. Overall I didn't need be made to feel foolish, incompetent or worthless though sadly it seems that this is often the way of the internet and is why I think it is in decline.
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The nanovna returned to work
I reflow the board and everything is normal now
Calibrated and reading my antennas
Thank you all for your help
|
Re: NanoVNA-H4 Calibration Loads
It may have been intentional, Roger, or at least fortuitous.
See the second article down here:
Mike - M0MLM
------------------------------------------------------------------------
*From:* Roger Need via groups.io [mailto:sailtamarack@...]
*Sent:* Sunday, 13 December 2020, 2:19 am
*Subject:* [nanovna-users] NanoVNA-H4 Calibration Loads
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Today I unboxed and tested a new NanoVNA-H4. The first thing I did was to measure the calibration loads supplied in the box. I tested them with a DE-5000 LCR meter at DC and 100 kHz. The short was .01 ohm but the "50 ohm" cal load was 50.78 ohms. This is not nearly as close as the "50 ohm" cal load in my NanoVNA-H which read 49.79 ohms. Both NanoVNAs are genuine Hugen products. I also noticed that there are physical differences and finish between the -H and H4 loads. Even the through connector is a different size.
Kurt Poulsen did a nice job characterizing the 2.8" -H loads and it would have been nice if the H4 had continued to use the same devices. I guess I will continue to use the old set which is closer to 50 ohms.
I though I would post this so others know that not all the cal loads are the same in Hugen's products. A photo of both is attached.
Roger
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I tested the 2 connectors and they are normal
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Re: NanoVNA-H4 Calibration Loads
Ask Kurt to characterize these?
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On Sun, 13 Dec 2020 at 05:33, Hugen <hugen@...> wrote: On Sun, Dec 13, 2020 at 10:19 AM, Roger Need wrote:
50.78 ohms
The load attached to the H4 has been re-matched to perform better at
higher frequencies. The 49.9 ohm load used earlier performed quite badly
above 2GHz, but the new and improved load can get S11 below -30dB at 6GHz.
For measurements that require higher frequencies, the new load better. For
UHF measurement, I suggest you use the load included with H4 for
calibration.
|
Re: NanoVNA-H4 Calibration Loads
On Sun, Dec 13, 2020 at 10:19 AM, Roger Need wrote:
50.78 ohms
The load attached to the H4 has been re-matched to perform better at higher frequencies. The 49.9 ohm load used earlier performed quite badly above 2GHz, but the new and improved load can get S11 below -30dB at 6GHz. For measurements that require higher frequencies, the new load better. For UHF measurement, I suggest you use the load included with H4 for calibration.
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Re: Bluetooth HC5 and nanoVNA-H
On 12/11/20 8:02 AM, Gyula Molnar wrote: Bring the necessary connection points to the back of a "female" type socket, so you only need to plug it in when you want to use it.
you could probably glue a 3-4 pin header (or the socket side) and the mate on the BT unit. There are also plenty of really tiny connectors from companies like Hirose or Omnetics.
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Re: NanoVNA-H4 Calibration Loads
I'm waiting on my H4 to be delivered and one of the reasons that I went through the trouble of ordering from Hugen (they don't ship to Serbia, had to ship it to Germany) was so I could use Kurt characterization files. FFS On Sun, 13 Dec 2020 at 03:19, Roger Need via groups.io <sailtamarack= [email protected]> wrote: Today I unboxed and tested a new NanoVNA-H4. The first thing I did was
to measure the calibration loads supplied in the box. I tested them with a
DE-5000 LCR meter at DC and 100 kHz. The short was .01 ohm but the "50
ohm" cal load was 50.78 ohms. This is not nearly as close as the "50 ohm"
cal load in my NanoVNA-H which read 49.79 ohms. Both NanoVNAs are genuine
Hugen products. I also noticed that there are physical differences and
finish between the -H and H4 loads. Even the through connector is a
different size.
Kurt Poulsen did a nice job characterizing the 2.8" -H loads and it would
have been nice if the H4 had continued to use the same devices. I guess I
will continue to use the old set which is closer to 50 ohms.
I though I would post this so others know that not all the cal loads are
the same in Hugen's products. A photo of both is attached.
Roger
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NanoVNA-H4 Calibration Loads
Today I unboxed and tested a new NanoVNA-H4. The first thing I did was to measure the calibration loads supplied in the box. I tested them with a DE-5000 LCR meter at DC and 100 kHz. The short was .01 ohm but the "50 ohm" cal load was 50.78 ohms. This is not nearly as close as the "50 ohm" cal load in my NanoVNA-H which read 49.79 ohms. Both NanoVNAs are genuine Hugen products. I also noticed that there are physical differences and finish between the -H and H4 loads. Even the through connector is a different size.
Kurt Poulsen did a nice job characterizing the 2.8" -H loads and it would have been nice if the H4 had continued to use the same devices. I guess I will continue to use the old set which is closer to 50 ohms.
I though I would post this so others know that not all the cal loads are the same in Hugen's products. A photo of both is attached.
Roger
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Re: Nanovna does not read signal
Does it power up?
John
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On Sat, Dec 12, 2020 at 4:24 PM Dave Fugleberg <dave.w0zf@...> wrote: the nanoVNA has to first produce the signal to see it reflected back...can
you verify with a receiver that it's outputting a signal ? You can set the
stimulus center frequency to whatever is convenient and set the span to 0
and it'll put out a signal at that frequency that you can pick up on a
nearby receiver.Might need to connect a piece of wire to CH0 to act as an
antenna.
Does it calibrate properly with the open/short/load standards? If it does,
that would indicate that it's both generating and receiving a signal.
On Sat, Dec 12, 2020 at 2:17 PM J¨²nior PY2ADA via groups.io <aaj280174=
[email protected]> wrote:
Yesterday I went to check the resonance of my EFHW antenna with the
nanovna h and found that in no port I can read the signal.
I removed it from the antenna and tested it with a simple dipole and it
also does not present a signal reading in the swr and logmag formats.
I believe the nanovna has a defective input component, as it connects and
I can access all functions.
Does anyone have any solution of what may be happening.
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Re: Nanovna does not read signal
the nanoVNA has to first produce the signal to see it reflected back...can you verify with a receiver that it's outputting a signal ? You can set the stimulus center frequency to whatever is convenient and set the span to 0 and it'll put out a signal at that frequency that you can pick up on a nearby receiver.Might need to connect a piece of wire to CH0 to act as an antenna. Does it calibrate properly with the open/short/load standards? If it does, that would indicate that it's both generating and receiving a signal. On Sat, Dec 12, 2020 at 2:17 PM J¨²nior PY2ADA via groups.io <aaj280174= [email protected]> wrote: Yesterday I went to check the resonance of my EFHW antenna with the
nanovna h and found that in no port I can read the signal.
I removed it from the antenna and tested it with a simple dipole and it
also does not present a signal reading in the swr and logmag formats.
I believe the nanovna has a defective input component, as it connects and
I can access all functions.
Does anyone have any solution of what may be happening.
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Can you successfully cal it? Dave - W?LEV On Sat, Dec 12, 2020 at 8:17 PM J¨²nior PY2ADA via groups.io <aaj280174= [email protected]> wrote: Yesterday I went to check the resonance of my EFHW antenna with the
nanovna h and found that in no port I can read the signal.
I removed it from the antenna and tested it with a simple dipole and it
also does not present a signal reading in the swr and logmag formats.
I believe the nanovna has a defective input component, as it connects and
I can access all functions.
Does anyone have any solution of what may be happening.
-- *Dave - W?LEV* *Just Let Darwin Work*
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Roger Need
schweppe
Barry K3EUI
Mike Wyatt
J¨²nior PY2ADA
