Re: AliExpress Purchase Issue - Credit Card Refused
I just purchased some PE4302 Attenuator chips with my Paypal Mastercard on Alibaba. No problems. I purchased my TinySA from them a few months ago. Also went smoothly. On Sun, Dec 27, 2020 at 4:25 PM john marks via groups.io <kb4uxc= [email protected]> wrote: RandL has the H4 back in stock
On Sunday, December 27, 2020, 4:22 PM, Sandra Carroll <smgvbest@...>
wrote:
Chases fraud systems does not like Aliexpress or many outside the USA
purchases. I get around this using paypal to aliexpress.
I used to work for Chase when they where implementing that fraud system.
I was the product installer for the POC at the time then started installing
it when I changed job to work for Nationwide.
Sandra
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Jim
Hill, w6ivw
Sent: Sunday, December 27, 2020 3:06 PM
To: [email protected]
Subject: Re: [nanovna-users] AliExpress Purchase Issue - Credit Card
Refused
I was successful today. I used a Citi card, and the transaction went
through. The Chase card I used to purchase the nanoVNA didn't work again
today. I thought of phoning Chase to see if they changed their policies,
but would face their phone tree which successfully prevents me from talking
to a human being.
It was not all bad. When I ordered again, I carefully checked to verify I
was using the DeepElec site, and ended up at a different page with more
items listed and bought a few more.
Ken; I like your idea. Later, when I can safely walk into a bank, i'll
look into it.
Jim
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I know I've seen threads about using the nanoVNA as a signal source, and
also working with active devices, but don't recall seeing anything about
input level limitations. I'm sure the information must have been there,
but it didn't mean anything to me at the time. It makes sense though, that
it couldn't handle too much of a signal level.
Fun stuff!
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On Sun, Dec 27, 2020 at 8:19 AM Bob M. <wa1mik@...> wrote: I was doing some preamp testing and measured the output of my S-A-A-2 at
about -10dBm. I didn't bother with peak-hold or anything like that, just
hooked it up and looked at the screen. I think there was a bit less signal
at the higher end, but only by a couple of dB.
The input of my unit does not like signals much higher than about -5dBm.
It seems these devices really expect a passive (i.e. <0dB gain) device to
be connected. I had to use one or two 10dB pads on the input of the preamp
to reduce the levels so the NanoVNA would produce accurate indications.
It looks like a later version of the NanoVNA has a selectable output
level, but even reducing it by 12dB doesn't help with a preamp that has
18dB gain.
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Re: AliExpress Purchase Issue - Credit Card Refused
RandL has the H4 back in stock
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On Sunday, December 27, 2020, 4:22 PM, Sandra Carroll <smgvbest@...> wrote: Chases fraud systems does not like Aliexpress or many outside the USA purchases.? I get around this using paypal to aliexpress.? I used to work for Chase when they where implementing that fraud system.? I was the product installer for the POC at the time then started installing it when I changed job to work for Nationwide. Sandra -----Original Message----- From: [email protected] < [email protected]> On Behalf Of Jim Hill, w6ivw Sent: Sunday, December 27, 2020 3:06 PM To: [email protected]Subject: Re: [nanovna-users] AliExpress Purchase Issue - Credit Card Refused I was successful today.? I used a Citi card, and the transaction went through.? The Chase card I used to purchase the nanoVNA didn't work again today. I thought of phoning Chase to see if they changed their policies, but would face their phone tree which successfully prevents me from talking to a human being. It was not all bad.? When I ordered again, I carefully checked to verify I was using the DeepElec site, and ended up at a different page with more items listed and bought a few more. Ken; I like your idea.? Later, when I can safely walk into a bank, i'll look into it. Jim
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Re: AliExpress Purchase Issue - Credit Card Refused
Chases fraud systems does not like Aliexpress or many outside the USA purchases. I get around this using paypal to aliexpress.
I used to work for Chase when they where implementing that fraud system. I was the product installer for the POC at the time then started installing it when I changed job to work for Nationwide.
Sandra
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-----Original Message----- From: [email protected] < [email protected]> On Behalf Of Jim Hill, w6ivw Sent: Sunday, December 27, 2020 3:06 PM To: [email protected]Subject: Re: [nanovna-users] AliExpress Purchase Issue - Credit Card Refused I was successful today. I used a Citi card, and the transaction went through. The Chase card I used to purchase the nanoVNA didn't work again today. I thought of phoning Chase to see if they changed their policies, but would face their phone tree which successfully prevents me from talking to a human being. It was not all bad. When I ordered again, I carefully checked to verify I was using the DeepElec site, and ended up at a different page with more items listed and bought a few more. Ken; I like your idea. Later, when I can safely walk into a bank, i'll look into it. Jim
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And a good reason to use a balun is that without it, you can't measure antenna impedance. (Or at least I cant.) Impedance bridge readings are wrong and do not change no matter what you do.
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Re: AliExpress Purchase Issue - Credit Card Refused
I was successful today. I used a Citi card, and the transaction went through. The Chase card I used to purchase the nanoVNA didn't work again today. I thought of phoning Chase to see if they changed their policies, but would face their phone tree which successfully prevents me from talking to a human being.
It was not all bad. When I ordered again, I carefully checked to verify I was using the DeepElec site, and ended up at a different page with more items listed and bought a few more.
Ken; I like your idea. Later, when I can safely walk into a bank, i'll look into it.
Jim
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Re: File /Absolute Beginner Guide to The NanoVNA/Absolute_Beginner_Guide_NanoVNA_v1_5.pdf uploaded
#file-notice
Martin, you have my vote for whatever office you choose to be elected for.
Thank you.
John
VE7KKQ
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On Sun, Dec 27, 2020 at 2:43 AM rrex lehman <WB8TDG@...> wrote: Thank you Martin that's great, very helpful !
Rex
WB8TDG
On Sat, Dec 26, 2020 at 4:13 PM Dave via groups.io <dvfuller=
[email protected]> wrote:
Martin it's people like you who make the world a better place to live in
thank you.
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Re: AliExpress Purchase Issue - Credit Card Refused
When I order things from Ali, I usually get an email from my bank asking did I *really* place this order? I answer "yes" and the transaction goes through. Of course, you need to have email communications set up with your bank for this to work. If you don't, then I expect the bank will just refuse to accept the charge and thus Ali will refuse to accept your card.
Ken
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I was doing some preamp testing and measured the output of my S-A-A-2 at about -10dBm. I didn't bother with peak-hold or anything like that, just hooked it up and looked at the screen. I think there was a bit less signal at the higher end, but only by a couple of dB.
The input of my unit does not like signals much higher than about -5dBm. It seems these devices really expect a passive (i.e. <0dB gain) device to be connected. I had to use one or two 10dB pads on the input of the preamp to reduce the levels so the NanoVNA would produce accurate indications.
It looks like a later version of the NanoVNA has a selectable output level, but even reducing it by 12dB doesn't help with a preamp that has 18dB gain.
|
Re: File /Absolute Beginner Guide to The NanoVNA/Absolute_Beginner_Guide_NanoVNA_v1_5.pdf uploaded
#file-notice
Thank you Martin that's great, very helpful ! Rex WB8TDG On Sat, Dec 26, 2020 at 4:13 PM Dave via groups.io <dvfuller= [email protected]> wrote: Martin it's people like you who make the world a better place to live in
thank you.
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On 12/26/20 5:22 PM, Oristo wrote: Any idea what the output levels are? /g/nanovna-users/wiki/13116#nanoVNA-power-output
Note well that the NanoVNA doesn't put out a sine wave (above 300 MHz), it uses the 3rd harmonic as a "frequency range extension" - so if your device is nonlinear or broadband, the measurement power isn't the same as the power into the device. I don't think it would produce correct results on something like a wideband minicircuits amp (like the ZX60-4016s I use all the time) - since it has gain from (almost)DC - 4 GHz - it will process everything, including the fundamental and the harmonics. Say you're measuring at 600 MHz, the NanoVNA is actually set to 200 MHz, and amplifier will see both 200 and 600 (and 1GHz, etc.) - the phase shift at those frequencies are different, so the phase you measure is some combination of them.
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AliExpress Purchase Issue - Credit Card Refused
In early November, I purchased a nanoVNA-f from DeepElec through their store in AliExpress, using a credit card. It was received in early December, with no problems. I was not sure about quality of the adapters as I was not sure if DeepElec supplied them, so just purchased a UHF to SMA adapter set. Mechanically, the set looked fine, so attempted to purchase some more adapters and other accessories today. This time, DeepElec refused my credit card. I tried a second card, with the same results.
Has anyone else has this problem recently?
Jim
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Re: Assorted NanoVNA-H4 observations
I always search for the answers before asking the questions. Most of the time that works well, but sometimes in search results are multiple answers, sometimes contradictory. Other times I don't know enough to specify the proper search term or phrase.
Search engines are magnificent things, but not all-knowing or all-powerful. They are just a tool, and if the tool doesn't find the job/question at hand they they are not very useful in that application.
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Re: File /Absolute Beginner Guide to The NanoVNA/Absolute_Beginner_Guide_NanoVNA_v1_5.pdf uploaded
#file-notice
Martin it's people like you who make the world a better place to live in thank you.
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Many thanks, Jim!
Any idea what the output levels are?
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On Sat, Dec 26, 2020 at 1:41 PM Jim Lux <jim@...> wrote: On 12/26/20 10:23 AM, stefan baartman wrote:
Can anyone point me to the Specifications, especially Max Input levels for this device?
Thanks!
Stefan K8SEB
I don't know that there's an actual "spec sheet" - there's some
discussion on the list a few months ago, with respect to "what might
burn it out".
On port 1 (the receive port, port 0 is the source/reflected) the first
thing is a 20dB attenuator, so R24, a 56 ohm resistor probably takes the
biggest hit. Then it's into the SA612 input.
The SA612 third order intercept is -13 dBm (which is really low) - the
part is designed for input levels like -45 dBm. Fig 13 in the data
sheet shows the mixer is fully saturated by -20dBm and starts to
compress around -30dBm. I think you probably don't want to see much
more than -10dBm into the receiver port of the NanoVNA, and -40 would be
better.
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On 12/26/20 10:23 AM, stefan baartman wrote: Can anyone point me to the Specifications, especially Max Input levels for this device?
Thanks!
Stefan K8SEB
I don't know that there's an actual "spec sheet" - there's some discussion on the list a few months ago, with respect to "what might burn it out". On port 1 (the receive port, port 0 is the source/reflected) the first thing is a 20dB attenuator, so R24, a 56 ohm resistor probably takes the biggest hit. Then it's into the SA612 input. The SA612 third order intercept is -13 dBm (which is really low) - the part is designed for input levels like -45 dBm.? Fig 13 in the data sheet shows the mixer is fully saturated by -20dBm and starts to compress around -30dBm.? I think you probably don't want to see much more than -10dBm into the receiver port of the NanoVNA, and -40 would be better.
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Can anyone point me to the Specifications, especially Max Input levels for this device?
Thanks!
Stefan K8SEB
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Re: Assorted NanoVNA-H4 observations
Okay, thanks. I'll try it out later.
Regards,
Jason
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On 2020-12-26 12:42 p.m., Dragan Milivojevic wrote: You need a serial terminal. Try cutecom, simple and easy.
On Sat, 26 Dec 2020 at 18:30, Jason Ringas <pantheriusmaximus@...>
wrote:
How is this done in Linux? I have the chart with all the commands, but
how do I get in there to begin with?
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Re: Assorted NanoVNA-H4 observations
You need a serial terminal. Try cutecom, simple and easy. On Sat, 26 Dec 2020 at 18:30, Jason Ringas <pantheriusmaximus@...> wrote: How is this done in Linux? I have the chart with all the commands, but
how do I get in there to begin with?
Thanks,
Jason
On 2020-12-26 4:05 a.m., stevepilotltd wrote:
1 To clear settings completely do it via CLI with clearconfig 1234 command ( command line interface). <snip>
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Ken Jamrogowicz
Bob M.
Oristo