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S21 offset

 

I have a NanoVNA-H: HW version 3.4 with Dislord firmware 1.2.20. I have run the SOLT calibration. When I leave CH0 and CH1 connected together and do an S21 Logmag plot, there is almost -3dB offset over the entire plot. Shouldn't there be a straight at 0dB? I know I can enter an offset value to compensate but that seems like a work-around rather than fixing the problem. What might I be doing wrong?


Re: NanoVNA for 120 ohm Twin wire Balanced lines

 

Some users have installed bluetooth adapters, which can give the same
isolation result.
These use the serial port available inside the nanovna.
You could also use a pair of opto-isolators on the internal serial port
lines, and connect a serial control port through them to give electrical
isolation. The cable wires would still be there, which may still have some
minor effect, even though they are electrically isolated.
Unfortunately you can't do an optical approach with the USB port, since it
requires electrical connectivity for power, etc.
Adding a true optical control port that uses optical cable is possible, but
would likely be more than the cost of the nanovna.

On Thu, Aug 31, 2023 at 4:24?AM Greg Strickland <greg@...>
wrote:

**Feature creep alert**

Could sensitive measurements be easier if Nano VNA had an optical
transmitter and companion receiver, or an internal memory to record "screen
shot" or measurements on a timer?






Re: Not available at Ali Express / Zeenko

 

Anything that uses PayPal or other 3rd party reputable card processing is safe.
You just have to know if a website is storing the data (uncommon these days)
or redirecting to a card processor.

On Thu, 31 Aug 2023 at 18:32, G4OJW <g4ojw@...> wrote:

OK, a million sounded like an exact number :-) but seriously, yes, this is why I use a virtual card which I can switch on and off whenever it is needed online and suggest everyone does that. Has worked for years and still works, with seemingly every company and including Ali Express. Only on the second order did they refuse the card.





Re: Not available at Ali Express / Zeenko

 

They don't and there is no such thing as real free shipping,
it was just included in the price.
Shipping is much cheaper from China or the rest of the world.
It has to do with agreements between states.

On Thu, 31 Aug 2023 at 16:52, Dick <w1ksz@...> wrote:

The Chinese Government subsidizes some of there
Postal System to a greater extent than the US Gov't
does for the USPS.

I have ordered $1.24 in parts from China and got free
shipping.


Re: Not available at Ali Express / Zeenko

 

This is allowed because China is considered a "developing" counry. It is the second largest economy but the GDP per person is lower than developed countries

Mike N2MS

Mike N2MS


On 08/31/2023 10:52 AM EDT Dick < w1ksz@... > wrote:


The Chinese Government subsidizes some of there
Postal System to a greater extent than the US Gov't
does for the USPS.

I have ordered $1.24 in parts from China and got free
shipping.

Not what I would call an even playing field.

73, Dick, W1KSZ
________________________________
From: [email protected] < [email protected] > on behalf of
Manfred Mornhinweg < manfred@... >
Sent: Thursday, August 31, 2023 7:48 AM
To: [email protected] < [email protected] >
Subject: Re: [nanovna-users] Not available at Ali Express / Zeenko


United Parcel Service (UPS Worldwide Expedited) $225.02
USPS (Priority Mail International?) $72.01
That's also why I stopped ordering from the US. At least RandL is willing
to ship by mail! Many, if not most US companies, refuse to ship by mail,
and only give a choice between DHL, UPS and FedEx, with shipping charges
like the one above.

That the USPS charges $72 for a small parcel isn't the fault of companies
like RandL, of course. But it's hard for me to understand why USPS charges
so much, while China Post charges $4 for shipping the same thing, just as
fast if not faster, fully trackable, over twice the distance! And also
because just a few years ago I could get Priority Mail parcels from the US
for $14 shipping charge. Why has it gone up 5-fold?

And the shipping charges of the Express companies are of course
ridiculous. With any parcel that's a little larger, it's often cheaper to
buy a two-way air ticket and travel to the US to pick up the parcel there
and bring it home in the suitcase, instead of having it shipped by one of
those companies!

In addition those Express companies raise high service charges on
delivery, at least in my country. If I buy something for $80 in the US,
plus $225 shipping by UPS, I have to pay $18 import tax, $61 VAT, $79 UPS
handling fee, and $15 VAT on the handling fee, and then the credit card
company applies a 5% money conversion charge.

Instead the postal service raises no handling fee, and small imports from
China are tax-free. So....

The sellers in the USA are usually very good, reliable, efficient, and
nice to deal with. But the high shipping charges, and in many cases an
unwillingness to ship by mail, have pretty much killed importing from the
US, for many of us living in "the rest of the world".










Re: Not available at Ali Express / Zeenko

 

The Chinese Government subsidizes some of there
Postal System to a greater extent than the US Gov't
does for the USPS.

I have ordered $1.24 in parts from China and got free
shipping.

Not what I would call an even playing field.

73, Dick, W1KSZ
________________________________
From: [email protected] <[email protected]> on behalf of Manfred Mornhinweg <manfred@...>
Sent: Thursday, August 31, 2023 7:48 AM
To: [email protected] <[email protected]>
Subject: Re: [nanovna-users] Not available at Ali Express / Zeenko

United Parcel Service (UPS Worldwide Expedited) $225.02
USPS (Priority Mail International?) $72.01
That's also why I stopped ordering from the US. At least RandL is willing to ship by mail! Many, if not most US companies, refuse to ship by mail, and only give a choice between DHL, UPS and FedEx, with shipping charges like the one above.

That the USPS charges $72 for a small parcel isn't the fault of companies like RandL, of course. But it's hard for me to understand why USPS charges so much, while China Post charges $4 for shipping the same thing, just as fast if not faster, fully trackable, over twice the distance! And also because just a few years ago I could get Priority Mail parcels from the US for $14 shipping charge. Why has it gone up 5-fold?

And the shipping charges of the Express companies are of course ridiculous. With any parcel that's a little larger, it's often cheaper to buy a two-way air ticket and travel to the US to pick up the parcel there and bring it home in the suitcase, instead of having it shipped by one of those companies!

In addition those Express companies raise high service charges on delivery, at least in my country. If I buy something for $80 in the US, plus $225 shipping by UPS, I have to pay $18 import tax, $61 VAT, $79 UPS handling fee, and $15 VAT on the handling fee, and then the credit card company applies a 5% money conversion charge.

Instead the postal service raises no handling fee, and small imports from China are tax-free. So....

The sellers in the USA are usually very good, reliable, efficient, and nice to deal with. But the high shipping charges, and in many cases an unwillingness to ship by mail, have pretty much killed importing from the US, for many of us living in "the rest of the world".


Re: Not available at Ali Express / Zeenko

 

United Parcel Service (UPS Worldwide Expedited) $225.02
USPS (Priority Mail International?) $72.01
That's also why I stopped ordering from the US. At least RandL is willing to ship by mail! Many, if not most US companies, refuse to ship by mail, and only give a choice between DHL, UPS and FedEx, with shipping charges like the one above.

That the USPS charges $72 for a small parcel isn't the fault of companies like RandL, of course. But it's hard for me to understand why USPS charges so much, while China Post charges $4 for shipping the same thing, just as fast if not faster, fully trackable, over twice the distance! And also because just a few years ago I could get Priority Mail parcels from the US for $14 shipping charge. Why has it gone up 5-fold?

And the shipping charges of the Express companies are of course ridiculous. With any parcel that's a little larger, it's often cheaper to buy a two-way air ticket and travel to the US to pick up the parcel there and bring it home in the suitcase, instead of having it shipped by one of those companies!

In addition those Express companies raise high service charges on delivery, at least in my country. If I buy something for $80 in the US, plus $225 shipping by UPS, I have to pay $18 import tax, $61 VAT, $79 UPS handling fee, and $15 VAT on the handling fee, and then the credit card company applies a 5% money conversion charge.

Instead the postal service raises no handling fee, and small imports from China are tax-free. So....

The sellers in the USA are usually very good, reliable, efficient, and nice to deal with. But the high shipping charges, and in many cases an unwillingness to ship by mail, have pretty much killed importing from the US, for many of us living in "the rest of the world".


Re: Not available at Ali Express / Zeenko

 

Basic understanding of how card processing works / how prevalent card
skimming is.
How do you imagine that someone selling something on Ebay gains access to your
credit card details?

On Thu, 31 Aug 2023 at 07:08, G4OJW <g4ojw@...> wrote:

Is that statistic based on your feeling, on some logical assumptions, or on a scientific analysis or a survey?


Re: NanoVNA for 120 ohm Twin wire Balanced lines

 

**Feature creep alert**

Could sensitive measurements be easier if Nano VNA had an optical transmitter and companion receiver, or an internal memory to record "screen shot" or measurements on a timer?


Re: Not available at Ali Express / Zeenko

 

On 30/08/2023 19:12, G4OJW wrote:
Yes but you guys are in USA. Of course, you should order from a USA
supplier. If I I want to order from Randl, here is what they'll charge me for
shipping:

United Parcel Service (UPS Worldwide Expedited) $225.02
USPS (Priority Mail International?) $72.01
.
.
.

If you can use your G4OJW address get it from Mirfield:



They do the spectrum analysers too:



73,
David GM8ARV
--
SatSignal Software - Quality software for you
Web:
Email: david-taylor@...
Twitter: @gm8arv


Re: Not available at Ali Express / Zeenko

 

You have a million times greater chance of your card details getting
stolen when paying for gas than
the same happening when using PayPal.

On Wed, 30 Aug 2023 at 23:00, Julio VE3FH via groups.io
<ve3fh@...> wrote:

I share your concerns. I bought my TinySA from the SeeSii store in ebay.ca, it and arrived in six days and shipping was USD $2.99, they do carry the NanoVNA H4 and I'll probably buy a NanoVNA from them shortly. The issue with ebay is that payments are processed by paypal so you risk your credit card being compromised, it happened to me at least three times already.
73,Julio VE3FH


Re: Not available at Ali Express / Zeenko

 

I share your concerns. I bought my TinySA from the SeeSii store in ebay.ca, it?and arrived in six days and shipping was USD $2.99, they do carry the NanoVNA H4 and I'll probably buy a NanoVNA from them shortly. The issue with ebay is that payments are processed by paypal so you risk your credit card being compromised, it happened to me at least three times already.
73,Julio VE3FH

On Wednesday, August 30, 2023 at 02:12:29 p.m. EDT, G4OJW <g4ojw@...> wrote:

Yes but you guys are in USA. Of course, you should order from a USA supplier. If I I want to order from Randl, here is what they'll charge me for shipping:

United Parcel Service (UPS Worldwide Expedited)??? $225.02
USPS (Priority Mail International?)??? $72.01

Only those two over-the-top options ON TOP of the $79 "special price". Like I said, smaller business USA thinks the rest of the world doesn't exist and is a risky inconvenience to be deterred, unlike the big business such as Amazon.

Ali Express: $59 and $5.92 shipping, I ordered before, arrived in about a week, no issues, but for earlier mentioned reasons won't do business with them. But that's still 72 dollars cheaper than Randl!

Amazon: FREE shipping, but they make sure Thailand gets their tax: $13.44 Import Fees Deposit & FREE Shipping to Thailand and the price of the NANO VNA H4? $59.99.

TOTAL price is LESS for me in Thailand ($73.43) via the USA Bezos Amazon and the approved online store AURSINC than for you in the USA via Randl's "Special Price" ($79). Assuming they ship to you for free.

Of course, the VNA is from China, I'm on the border of China, and Bezos has his wallet in China, so that all makes sense but I'm sure it's a similar price to USA and no two whacko options of $72 or $225 plus two cents shipping.

Isn't it wonderful how these companies such as DHL make an absolute killing? No wonder the ALL supported C-v-D.

Ali Baba would even beat Amazon, mainly because it has some way to avoid paying Thailand import taxes.

It's still unfortunate that it's difficult to compete with Ali/Amazon but that's the way most wanted it from back when there was a chance to support small businesses, but the cheaper dollars of the big ones attracted short sightedness.

Thanks to the many who provided advice, I couldn't see any PayPal option on Ali Express and then after reading some other feedback here decided Amazon would be the safest choice, from the approved AURSINC store.


Re: How do you measure a car antenna?

 

It used to be that all we had to worry about was light pollution, just try to find a place where you can see the Milky Way.

As more and more RF/wireless devices and other electronic devices that utilize fast switching designs come into existence more and more of the electromagnetic spectrum is becoming hopelessly polluted.

Progress?

On 8/30/2023 11:36 AM, G4OJW wrote:
Indeed. Unfortunately they don't work for us though, but big industry, so they allow all sorts of RFI to pass into countries at the borders. That's the point at which they could do their job and economically if they wanted, raking in huge fines from their friends in Big Industry. Likely not at the local level after sales going checking various vehicles etc. That'd be too costly. Rising noise levels is a headache for many and kills the hobby. I'm in a low noise area and find that not many stations that I can hear with a clear 559 can hear me. More interesting if stations would exchange RSN with N for local noise level, and not the T9. The late W4RNL also advocated for such. E.g. system.




Re: How do you measure a car antenna?

 

Did the Commission or its representative look to see if the device is causing harmful interference?

Probably not...

Because if they had, they would have found that the device IS causing harmful interference.

Interesting how that works.

On 8/30/2023 11:16 AM, G4OJW wrote:
Why? Did the Commission or its representative find the device is causing harmful interference? NO.

On Wed, Aug 30, 2023 at 01:10 PM, Geoff Peters - AB6BT wrote:

the Commission or its representative that the device is causing harmful
interference


Re: How do you measure a car antenna?

 

"The operator of the exempted device shall be required to stop operating the device upon a finding by the Commission or its representative that the device is causing harmful interference. Operation shall not resume until the condition causing the harmful interference has been corrected."

So I guess you have to stop operating your electric vehicle...

On 8/30/2023 10:41 AM, Frank Evans wrote:
The operator of the exempted device shall be required to stop operating the device upon a finding by the Commission or its representative that the device is causing harmful interference. Operation shall not resume until the condition causing the harmful interference has been corrected.


Re: How do you measure a car antenna?

 

Here's the exempted devices paragraph from Title 47, C.F.R. Part 15
============================================================


¡ì 15.103 Exempted devices.

Except as provided in paragraph (j) <(j)> of this section, the following devices are subject only to the general conditions of operation in ¡ì¡ì 15.5 <> and 15.29 <>, and are exempt from the specific technical standards and other requirements contained in this part. The operator of the exempted device shall be required to stop operating the device upon a finding by the Commission or its representative that the device is causing harmful interference. Operation shall not resume until the condition causing the harmful interference has been corrected. Although not mandatory, it is strongly recommended that the manufacturer of an exempted device endeavor to have the device meet the specific technical standards in this part.

(a) A digital device utilized exclusively in any transportation vehicle including motor vehicles and aircraft.

(b) A digital device used exclusively as an electronic control or power system utilized by a public utility or in an industrial plant. The term /public utility/ includes equipment only to the extent that it is in a dedicated building or large room owned or leased by the utility and does not extend to equipment installed in a subscriber's facility.

(c) A digital device used exclusively as industrial, commercial, or medical test equipment.

(d) A digital device utilized exclusively in an appliance, e.g., microwave oven, dishwasher, clothes dryer, air conditioner (central or window), etc.

(e) Specialized medical digital devices (generally used at the direction of or under the supervision of a licensed health care practitioner) whether used in a patient's home or a health care facility. Non-specialized medical devices, /i.e./, devices marketed through retail channels for use by the general public, are not exempted. This exemption also does not apply to digital devices used for record keeping or any purpose not directly connected with medical treatment.

(f) Digital devices that have a power consumption not exceeding 6 nW.

(g) Joystick controllers or similar devices, such as a mouse, used with digital devices but which contain only non-digital circuitry or a simple circuit to convert the signal to the format required (e.g., an integrated circuit for analog to digital conversion) are viewed as passive add-on devices, not themselves directly subject to the technical standards or the equipment authorization requirements.

(h) Digital devices in which both the highest frequency generated and the highest frequency used are less than 1.705 MHz and which do not operate from the AC power lines or contain provisions for operation while connected to the AC power lines. Digital devices that include, or make provision for the use of, battery eliminators, AC adaptors or battery chargers which permit operation while charging or that connect to the AC power lines indirectly, obtaining their power through another device which is connected to the AC power lines, do not fall under this exemption.

(i) Responsible parties should note that equipment containing more than one device is not exempt from the technical standards in this part unless all of the devices in the equipment meet the criteria for exemption. If only one of the included devices qualifies for exemption, the remainder of the equipment must comply with any applicable regulations. If a device performs more than one function and all of those functions do not meet the criteria for exemption, the device does not qualify for inclusion under the exemptions.

(j) Notwithstanding other provisions of this section, the rules governing certification apply to any equipment produced by any entity identified on the Covered List, as established pursuant to ¡ì 1.50002 of this chapter <>, as producing covered communications equipment.

======================================================================

Frank Evans

On 8/30/2023 10:46 AM, Mike C. wrote:
Hmmmm... so you'll be 'testing' while you're applying the brakes???

On 8/30/2023 10:58 AM, KENT BRITAIN wrote:
? Well, some of them kind of do.? ? ?Part of Dynamic Braking!
Kent
???? On Wednesday, August 30, 2023 at 09:14:21 AM CDT, Mike C.<mg@...>? wrote:
? ? EV's don't have "alternators". :0)

On 8/27/2023 5:52 PM, Rick Murphy wrote:
The AM radio in my car works just fine. Chevy BoltEV.
How short our memories are - does nobody else remember "alternator noise"?
Cars are mobile noise generators.

73,
?? ? ? -Rick

On Sat, Aug 26, 2023 at 9:47?PM N7RWB Craig Cherry via groups.io
<craig.cherry@...> ? wrote:

Ken, looking through FCC part 15 rules on emissions, I don¡¯t see any
exemption for electric car motors or power systems. Do you have a reference
to a FCC document for the exemption you mentioned?















Re: How do you measure a car antenna?

 

Hmmmm... so you'll be 'testing' while you're applying the brakes???

On 8/30/2023 10:58 AM, KENT BRITAIN wrote:
Well, some of them kind of do.? ? ?Part of Dynamic Braking!
Kent
On Wednesday, August 30, 2023 at 09:14:21 AM CDT, Mike C.<mg@...> wrote:
EV's don't have "alternators". :0)

On 8/27/2023 5:52 PM, Rick Murphy wrote:
The AM radio in my car works just fine. Chevy BoltEV.
How short our memories are - does nobody else remember "alternator noise"?
Cars are mobile noise generators.

73,
? ? ? -Rick

On Sat, Aug 26, 2023 at 9:47?PM N7RWB Craig Cherry via groups.io
<craig.cherry@...> ? wrote:

Ken, looking through FCC part 15 rules on emissions, I don¡¯t see any
exemption for electric car motors or power systems. Do you have a reference
to a FCC document for the exemption you mentioned?












Re: nano VNA-H will not connect via USB to control apps on Win10 - help please

 

1. Nanovna-H and Nanovna-H4 do not require a driver under Windows 10 to
connect to Nanovna-app, etc.
2. So either there is some problem with your nanovna, the cable, or the
computer.
3. I recommend first testing the nanovna/cable by using a friend's Win10
computer (no previous nanovna connection attempts).
3a. Open device manager
3b. Plug in usb cable to nanovna and computer (with nanovna off)
3c. Turn on nanovna.
3d. The device manager screen should update as the USB PnP detects the
device
3e. It should appear under the "Ports (COM & LPT)" category as "USB
Serial Device"
3f. When you turn off the nanovna, that same device should disappear
from the list.
3g. If this does not happen, either the cable or the nanovna has a
problem.
4. If the test in 3 works, your nanovna and cable are good, and there is
something goofed up in your computer to diagnose.

Which version of firmware is in your nanovnaa-H? It shouldn't matter, but
would give us a frame of reference to help you.
Stan


On Wed, Aug 30, 2023 at 12:52?AM Brian Stokes <brianstokes@...>
wrote:

Hi Paul

There are no devices shown in gray. nanoVNA-QT can't see the device.
Instructions in say it needs a
driver. I installed CypressDriverInstaller_1.exe

Still doesn't work.

Thanks






Re: How do you measure a car antenna?

 

Also, the older tube type car radios used vibrators and a transformer to
generate the necessary plate voltages for the tubes. Those vibrator
circuits generated some noise.

Zack W9SZ

On Wed, Aug 30, 2023 at 9:58?AM KENT BRITAIN <WA5VJB@...> wrote:

Well, some of them kind of do. Part of Dynamic Braking!
Kent
On Wednesday, August 30, 2023 at 09:14:21 AM CDT, Mike C. <mg@...>
wrote:

EV's don't have "alternators". :0)

On 8/27/2023 5:52 PM, Rick Murphy wrote:
The AM radio in my car works just fine. Chevy BoltEV.
How short our memories are - does nobody else remember "alternator
noise"?
Cars are mobile noise generators.

73,
-Rick

On Sat, Aug 26, 2023 at 9:47?PM N7RWB Craig Cherry via groups.io
<craig.cherry@...> wrote:

Ken, looking through FCC part 15 rules on emissions, I don¡¯t see any
exemption for electric car motors or power systems. Do you have a
reference
to a FCC document for the exemption you mentioned?
















Re: Not available at Ali Express / Zeenko

 

Same here. I've been very happy with it.

Zack W9SZ

On Wed, Aug 30, 2023 at 9:51?AM Pirok-W4UNX <jason.pirok@...> wrote:

Randl.com is where I got my H4.

On Wed, Aug 30, 2023, 09:24 KD2YYI <tim.sooley@...> wrote:

As someone who just got nanoVNA 4 from amazon I recommend following this
guide from nanovna.com to ensure you get a legit one that is firmware
upgradable.