Re: Not available at Ali Express / Zeenko
That's a great thought, unfortunately, I haven't had luck with two disputes using PayPal.
In my case it seemed to come down to a "my word versus theirs thing.
The problem was difficult to prove using words and imagery. Because of that, no matter if I'm dealing with Ali, Banggood, or others, my spending limit all continue to be USD 25 (or so). Those stores are so far away it's not worth my risking shipping costs if they will exceed the replacement costs.
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Re: How do you measure a car antenna?
It is generally believed that the move to eliminate? AM radios in? cars is political not technical .Most conservative programs are on the AM radio band.
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On Saturday, August 26, 2023 at 11:03:32 AM CDT, W0LEV <davearea51a@...> wrote: The 4-Runner was a standard internal combustion engine.? The Ford Lightning is an EV.? With the EV's comes a massive amount of RFI.? It's so bad that manufacturers are eliminating AM radio from their vehicles. I'd venture a guess the problem is not with the antenna, but with the EV technology in general. Dave - W?LEV On Sat, Aug 26, 2023 at 1:22?PM Lawrance A. Schneider < llaassllaaass@...> wrote: Enclosed is the photo of a car antenna's mounting.? Note it is a single
pin.? Also enclosed is a picture of my Baofeng's antenna post.? Note that
the car antenna is a single post/pin.? The Baofeng's antenna has a pin
inside a mounting.? Thus, to measure the Baofeng's antenna you simply
connect it to the nanavna.? How to do the car antenna???
The reason I ask is experience with my old Toyota 4Runner's radio and my
new Ford Lightning's radio.? The 4Runner radio would work 50 to 80 miles
from a tower.? The Lightning will start to fade 20 miles from the same
towers.? Is the fault with the antenna or the radio???
Thank you for any cogent answer.? ? ? ? ? larry
-- *Dave - W?LEV* -- Dave - W?LEV
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Re: How do you measure a car antenna?
The 4-Runner was a standard internal combustion engine. The Ford Lightning is an EV. With the EV's comes a massive amount of RFI. It's so bad that manufacturers are eliminating AM radio from their vehicles. I'd venture a guess the problem is not with the antenna, but with the EV technology in general. Dave - W?LEV On Sat, Aug 26, 2023 at 1:22?PM Lawrance A. Schneider < llaassllaaass@...> wrote: Enclosed is the photo of a car antenna's mounting. Note it is a single
pin. Also enclosed is a picture of my Baofeng's antenna post. Note that
the car antenna is a single post/pin. The Baofeng's antenna has a pin
inside a mounting. Thus, to measure the Baofeng's antenna you simply
connect it to the nanavna. How to do the car antenna???
The reason I ask is experience with my old Toyota 4Runner's radio and my
new Ford Lightning's radio. The 4Runner radio would work 50 to 80 miles
from a tower. The Lightning will start to fade 20 miles from the same
towers. Is the fault with the antenna or the radio???
Thank you for any cogent answer. larry
-- *Dave - W?LEV* -- Dave - W?LEV
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Re: How do you measure a car antenna?
Hi, Larry,
Note that measurements with a VNA will examine the impedance presented by the antenna as a source but not its efficiency at receiving signals. If you compare two antennas, you might see a better impedance match with one, but a higher level incoming signal from the other.
If you have the ability to connect an external radio with an S-meter or signal level indication of some kind (maybe a spectrum analyzer), you might try that with both vehicles to see how much signal is arriving via each antenna. That, combined with the VNA readings, might give you some idea of how each antenna is performing.
Note that short receiving antennas are often not impedance matched to their receivers. Even if they are, the impedances of the antenna and the receiver may be much higher than 50 ohms so you might see a really high SWR, against 50 ohms, from a properly operating antenna.
73,
Maynard
W6PAP
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On 8/26/23 06:22, Lawrance A. Schneider wrote: Enclosed is the photo of a car antenna's mounting. Note it is a single pin. Also enclosed is a picture of my Baofeng's antenna post. Note that the car antenna is a single post/pin. The Baofeng's antenna has a pin inside a mounting. Thus, to measure the Baofeng's antenna you simply connect it to the nanavna. How to do the car antenna???
The reason I ask is experience with my old Toyota 4Runner's radio and my new Ford Lightning's radio. The 4Runner radio would work 50 to 80 miles from a tower. The Lightning will start to fade 20 miles from the same towers. Is the fault with the antenna or the radio???
Thank you for any cogent answer. larry
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Re: Not available at Ali Express / Zeenko
Or use PayPal which offers a better level of protection than dealing directly with AliExpress.
Lester B Veenstra K1YCM M?YCM W8YCM 6Y6Y W8YCM/6Y 6Y8LV (Reformed USNSG CTM1)
lester@...
452 Stable Ln
Keyser WV 26726 USA
GPS: 39.336826 N 78.982287 W (Google)
GPS: 39.33682 N 78.9823741 W (GPSDO)
Telephones:
Home: +1-304-289-6057
US cell +1-304-790-9192
Jamaica cell: +1-876-456-8898
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-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Gary W9TD Sent: Saturday, August 26, 2023 11:02 AM To: [email protected]Subject: Re: [nanovna-users] Not available at Ali Express / Zeenko I had the same problem with Aliexpress not taking my card. I think they view it as stolen or bogus and you need to call them and clear it up (Ha, Ha). I fixed the problem by opening a new account and using a different card. Gary W9TD
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Re: Not available at Ali Express / Zeenko
I had the same problem with Aliexpress not taking my card. I think they view it as stolen or bogus and you need to call them and clear it up (Ha, Ha). I fixed the problem by opening a new account and using a different card.
Gary
W9TD
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Re: How do you measure a car antenna?
Here's a document of vehicle rear window antenna concept:
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Re: How do you measure a car antenna?
Can you take a photo of the car antenna connection that's in focus? Zack W9SZ On Sat, Aug 26, 2023 at 8:22?AM Lawrance A. Schneider < llaassllaaass@...> wrote: Enclosed is the photo of a car antenna's mounting. Note it is a single
pin. Also enclosed is a picture of my Baofeng's antenna post. Note that
the car antenna is a single post/pin. The Baofeng's antenna has a pin
inside a mounting. Thus, to measure the Baofeng's antenna you simply
connect it to the nanavna. How to do the car antenna???
The reason I ask is experience with my old Toyota 4Runner's radio and my
new Ford Lightning's radio. The 4Runner radio would work 50 to 80 miles
from a tower. The Lightning will start to fade 20 miles from the same
towers. Is the fault with the antenna or the radio???
Thank you for any cogent answer. larry
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Re: How do you measure a car antenna?
Larry- Perhaps someone here who knows the theory could briefly cover impact of antenna impedance when the antenna is used for receiving.
I am posting because to me it seems the essence of your question is vehicle broadcast radio reception differences between various vehicle models.
That is a big subject probably best suited to an article.
Consider that a vehicle antenna may have a directional pattern, and you need to be driving in the same direction and road when comparing. VHF FM broadcast propagation changes and the effect is more pronounced at distance. You need to make a comparison between vehicles under similar propagation conditions.
I think if you are OK making a physical and visual change to your vehicle, you do what you can to make a better antenna than what was provided "OEM" by the manufacturer. Consider that the OEM radio or entertainment center was built as an integrated system, and changing the antenna might not work well with the OEM radio.
Back in the old days with an analog FM radio in a passenger vehicle, the radio person would mount a 1/4 wave whip at 100 MHz right in the center of the car cabin roof and make a solid connection to the metal roof for the coax shield. These days, nearly all vehicles have a disguised antenna that has compromises this group knows well.
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Re: Not available at Ali Express / Zeenko
I've had good results with Banggood. But you are always taking a risk
ordering from any of these companies. They have zero customers service.
Banggood seems to be the least horrible!
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On Sat, Aug 26, 2023, 9:07 AM G4OJW <g4ojw@...> wrote: Please note: lists Ali Express / Zeenko.
This is no longer available, Zeenko is selling no products currently.
I tried ordering via Ali Express some months ago, a few days after
successfully buying an AT-100M on Ali Express, to be told that they could
no longer accept my Visa card, which has worked and still works for many
years without any problems. I thus cannot recommend Ali Express in general
thus with a 50% success rate only, as their systems are odd.
However, can the above page be updated, and are there any others that are
not listed and reputable? The prices vary substantially, the Ali Express
was the best price via Zeenko before.
Thank you
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How do you measure a car antenna?
Enclosed is the photo of a car antenna's mounting. Note it is a single pin. Also enclosed is a picture of my Baofeng's antenna post. Note that the car antenna is a single post/pin. The Baofeng's antenna has a pin inside a mounting. Thus, to measure the Baofeng's antenna you simply connect it to the nanavna. How to do the car antenna???
The reason I ask is experience with my old Toyota 4Runner's radio and my new Ford Lightning's radio. The 4Runner radio would work 50 to 80 miles from a tower. The Lightning will start to fade 20 miles from the same towers. Is the fault with the antenna or the radio???
Thank you for any cogent answer. larry
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Re: VNA and antenna matching : calculating reactance needed to match
Thank you for all the replies.
The first six pages of seem to address my question. is very similar content.
"Notes on Antenna Tuners: The L-Network and Impedance Matching" by K6JCA is interesting
Kind regards,
Andrew
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Re: NanoVNA-App SWR graph does not match H4 graph
Thank you, Stan. That makes perfect sense. I was not aware that calibration sources could be different. I will check that option.
Thanks again,
Bob, KN4HH
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On Aug 25, 2023, at 3:50 PM, Stan Dye <standye@...> wrote:
?If the displays are different while doing a measurement, it is very likely
a calibration issue. Nanovna-app allows you to select the vna calibration
or the app calibration. Make sure that is set to vna to compare traces.
Note that the app receives the same exact s11 data that the nano uses for
display, so if the displays are different, there is a difference in the
calibration or display settings between the two.
On Fri, Aug 25, 2023, 10:42 AM W0LEV <davearea51a@...> wrote:
QUOTE: Consider this a benefit of the tiny battery powered Nano VNA. A
measurement can be made with minimal impact on the device under test.
Indeed. You hit the nail on squarely on the head. Consider the HP 8753C
with the S-Parameter test set. It weight in around 100+ lbs. I can not
use it with anything that requires a counterpoise or isolation from the
instrument as its too large, sits on a metal shelf, and is connected to the
power grid: a MAJOR increase in any counterpoise. The NANOVNAs allow me
to make measurments that the 8753C really can not make.
However, when one needs to measure at or above our 70-cm band, the size of
the NANOs become significant.
Dave - W?LEV
On Fri, Aug 25, 2023 at 3:50?PM Greg Strickland <greg@...>
wrote:
Last night I was measuring a high Q resonant circuit on the bench with
Nano VNA on battery. The battery was getting low and without physically
moving anything I connected a USB cable from Nano VNA to laptop a few feet
away. The measurement moved just a bit. Not a cause for concern because
it makes sense. Consider this a benefit of the tiny battery powered Nano
VNA. A measurement can be made with minimal impact on the device under
test.
--
*Dave - W?LEV*
--
Dave - W?LEV
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Re: NanoVNA-App SWR graph does not match H4 graph
If the displays are different while doing a measurement, it is very likely
a calibration issue. Nanovna-app allows you to select the vna calibration
or the app calibration. Make sure that is set to vna to compare traces.
Note that the app receives the same exact s11 data that the nano uses for
display, so if the displays are different, there is a difference in the
calibration or display settings between the two.
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Show quoted text
On Fri, Aug 25, 2023, 10:42 AM W0LEV <davearea51a@...> wrote: QUOTE: Consider this a benefit of the tiny battery powered Nano VNA. A
measurement can be made with minimal impact on the device under test.
Indeed. You hit the nail on squarely on the head. Consider the HP 8753C
with the S-Parameter test set. It weight in around 100+ lbs. I can not
use it with anything that requires a counterpoise or isolation from the
instrument as its too large, sits on a metal shelf, and is connected to the
power grid: a MAJOR increase in any counterpoise. The NANOVNAs allow me
to make measurments that the 8753C really can not make.
However, when one needs to measure at or above our 70-cm band, the size of
the NANOs become significant.
Dave - W?LEV
On Fri, Aug 25, 2023 at 3:50?PM Greg Strickland <greg@...>
wrote:
Last night I was measuring a high Q resonant circuit on the bench with
Nano VNA on battery. The battery was getting low and without physically
moving anything I connected a USB cable from Nano VNA to laptop a few feet
away. The measurement moved just a bit. Not a cause for concern because
it makes sense. Consider this a benefit of the tiny battery powered Nano
VNA. A measurement can be made with minimal impact on the device under
test.
--
*Dave - W?LEV*
--
Dave - W?LEV
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Re: Trouble calibrating NanoVna Classic after upgrade to 1.2.20
Flash old firmware and see if you get the same problem.
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On Fri, 25 Aug 2023 at 19:58, kumuzu1 <bulchandani@...> wrote:
I'm hoping someone can help me with my inability to calibrate my NanoVna
classic after upgrading
sucessfully to 1.2.20h.dfu.
While attempting to debug this problem, I did the following:
1) Ran a 'clearconfig 1234' via putty
2) Did a Touch Cal
3) Reduced the si535I frequency to 290 Mhz
4) Reset the calibration before starting the calibration process
But the nanoVna just wouldn't confirm a successful calibration when I
tested the Smith Chart with a 50 ohm or short load. I've attached an image
of what i see.
The odd part is that every so often the nanoVna does calibrate successfully
but when
I try and repeat the process it fails to calibrate.
Any clues? I love this little device and it is now a matter of personal
pride to get it to work!
Sanjay
AI6PM
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Trouble calibrating NanoVna Classic after upgrade to 1.2.20
I'm hoping someone can help me with my inability to calibrate my NanoVna
classic after upgrading
sucessfully to 1.2.20h.dfu.
While attempting to debug this problem, I did the following:
1) Ran a 'clearconfig 1234' via putty
2) Did a Touch Cal
3) Reduced the si535I frequency to 290 Mhz
4) Reset the calibration before starting the calibration process
But the nanoVna just wouldn't confirm a successful calibration when I
tested the Smith Chart with a 50 ohm or short load. I've attached an image
of what i see.
The odd part is that every so often the nanoVna does calibrate successfully
but when
I try and repeat the process it fails to calibrate.
Any clues? I love this little device and it is now a matter of personal
pride to get it to work!
Sanjay
AI6PM
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Re: NanoVNA-App SWR graph does not match H4 graph
QUOTE: Consider this a benefit of the tiny battery powered Nano VNA. A measurement can be made with minimal impact on the device under test. Indeed. You hit the nail on squarely on the head. Consider the HP 8753C with the S-Parameter test set. It weight in around 100+ lbs. I can not use it with anything that requires a counterpoise or isolation from the instrument as its too large, sits on a metal shelf, and is connected to the power grid: a MAJOR increase in any counterpoise. The NANOVNAs allow me to make measurments that the 8753C really can not make. However, when one needs to measure at or above our 70-cm band, the size of the NANOs become significant. Dave - W?LEV On Fri, Aug 25, 2023 at 3:50?PM Greg Strickland <greg@...> wrote: Last night I was measuring a high Q resonant circuit on the bench with
Nano VNA on battery. The battery was getting low and without physically
moving anything I connected a USB cable from Nano VNA to laptop a few feet
away. The measurement moved just a bit. Not a cause for concern because
it makes sense. Consider this a benefit of the tiny battery powered Nano
VNA. A measurement can be made with minimal impact on the device under
test.
-- *Dave - W?LEV* -- Dave - W?LEV
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Re: NanoVNA-App SWR graph does not match H4 graph
Dave, I understand your point about the counterpoise extension. However, I would think that the SWR readings would shift the same for both displays. What am I missing.
Bob, KN4HH
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On Aug 25, 2023, at 11:18 AM, W0LEV <davearea51a@...> wrote:
?When connected to the PC or laptop, the effective counterpoise is much
longer than when not connected. The counterpoise consists of anything
connected to the measuring unit, including the laptop/PC through the USB
cable. There is nothing wrong with either measurement. You must
electrically remove the "extension" of the counterpoise when connected to
the PC/laptop.
Dave - W?LEV
On Fri, Aug 25, 2023 at 3:05?PM Bob Watson via groups.io <kn4hhptc=
[email protected]> wrote:
I am using a NanoVNA H4 and NanoVNA-App for SWR display. I connected my
end fed half wave antenna to the CNA and compared the two graphical
displays. Both the NanoVNA and H4 displays were set for identical SWR and
frequency ranges (1:1 to 3:1 and 1-30Mhz).
The difference in displays is dramatic (ie 3Mhz. 2.1:1 vs over 3:1 SWR).
Has anyone observed a difference between the H4 and external display
software.
I would appreciate any comments.
Bob, KN4HH
--
*Dave - W?LEV*
--
Dave - W?LEV
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Re: NanoVNA-App SWR graph does not match H4 graph
On Fri, Aug 25, 2023 at 08:50 AM, Greg Strickland wrote:
Last night I was measuring a high Q resonant circuit on the bench with Nano
VNA on battery. The battery was getting low and without physically moving
anything I connected a USB cable from Nano VNA to laptop a few feet away. The
measurement moved just a bit. Not a cause for concern because it makes sense.
Consider this a benefit of the tiny battery powered Nano VNA. A measurement
can be made with minimal impact on the device under test.
Performance/measurements of the NanoVNA might change slightly with battery level. Try making the same standalone measurement with a full battery. Roger
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Re: NanoVNA-App SWR graph does not match H4 graph
Last night I was measuring a high Q resonant circuit on the bench with Nano VNA on battery. The battery was getting low and without physically moving anything I connected a USB cable from Nano VNA to laptop a few feet away. The measurement moved just a bit. Not a cause for concern because it makes sense. Consider this a benefit of the tiny battery powered Nano VNA. A measurement can be made with minimal impact on the device under test.
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Twenty4pack
Gary W9TD
Bob Watson
Roger Need