开云体育

H4_REV4_3.pdf

Would you have the same for my nanovna-F I don't understand anything in github to treat this myself.
--
F1AMM Fran?ois

-----Message d'origine-----

De la part de Roger Need via
mardi 9 ao?t 2022 18:17

On 8/9/22 4:03 PM, Brian D wrote:

"Dave W6OQ via groups.io" <david.hostetler@...> wrote:

On Tue, Aug 9, 2022 at 12:16 PM, Ray W8LYJ wrote:

The only reason amateurs like to operate an antenna at or NEAR resonance
is because the feed point impedance is low so it’s easier to match.

Exactly! But not just amateurs, everyone!

Resonance could be a paralell resonance, as with a full wave dipole, which
is high impedance.

What one wants to avoid (with some transmitters) is too much reactive component - sure, you can cancel it with a passive component, but that component will have some loss AND the required value changes with frequency.

So if you have a transmitter that wants to see High Z, then you might choose that full wavelength doublet. If your transmitter wants to see low Z, then maybe a 1/4 wave over a ground plane (~35 ohms at resonance).

For a practical system engineering solution, leaving aside a regulatory constraint (like 1500 W PEP), you want to trade mismatch (not getting as much power to the antenna as you might with a match) vs loss in matching components vs loss in a passive pad (if the transmitter can't tolerate mismatch).

Lots of people (non-amateurs) use a terminated folded dipole as a very wide band low gain antenna, because they have RF power to burn, and they don't have to worry about (auto)tuning a matching network.

Many collinear arrays are also high-Z. That quoted statement from ARRL is
a gross over simplification! Dipoles, Yagis, yes. But there are many
common radiating structures that do not offer low-Z to match.

For my long doublet (half-wave resonance is about 950 kHz) fed with
parallel conductor transmission line I use for 160 through 6-meters the
real part of the measured impedance ranges from 12 to 1160 ohms in the
shack. After measuring the complex impedance in the shack and spending a
lot of time on SimSmith, I designed and built my own antenna matching unit
(a.k.a., "antenna tuner").

Dave - W?LEV

--
Dave - W?LEV

"Dave W6OQ via groups.io" <david.hostetler@...> wrote:

On Tue, Aug 9, 2022 at 12:16 PM, Ray W8LYJ wrote:

The only reason amateurs like to operate an antenna at or NEAR resonance
is because the feed point impedance is low so it’s easier to match.

Exactly! But not just amateurs, everyone!

Resonance could be a paralell resonance, as with a full wave dipole, which
is high impedance.

--
Brian D
G3VGZ G8AOE G3T
IO94im

On Tue, Aug 9, 2022 at 12:16 PM, Ray W8LYJ wrote:

The only reason amateurs like to operate an antenna at or NEAR resonance is
because the feed point impedance is low so it’s easier to match.

Exactly! But not just amateurs, everyone!

Thanks, but still a problem.

Wouldn’t download with Chrome, but as advised I used Edge. Initially said it wouldn’t download because of malware risk, but ignored that and downloaded.

When clicked to open, it advised a version 4 was available. Clicking ok then led to the programme opening, but clicking connect, with correct COM port, led to no data showing.

David

On Tue, Aug 9, 2022 at 11:02 AM, Kyle Claisse wrote:

Awesome, that schematic looks correct! Its definitely not the cable, theres no
current draw when the switch is off but when the switch is on the USB port
draws around 300mA but doesn't charge the battery no matter how long the
device is left on that way.

You should be drawing current when the NanoVNA is off if the battery needs charging. The battery has a protection circuit in it to prevent over and undercharge. Perhaps that has failed. You can see it through the yellow Kapton tape.

Try taking the battery out of the nanoVNA and see if it will take current from an adjustable power supply. Start with a low voltage and then move up slowly to 4.1 Volts.

Roger

thank you

martin
n6qlh

On Tue, Aug 9, 2022 at 12:14 PM Larry McElhiney via groups.io <lmcelhiney=
[email protected]> wrote:

Hi Martin,
I do not use any Malware protection on my iPads, but a search for iOS
Malware should give you options.

Larry AC9OX

Sent from Yahoo Mail for iPad

From ARRL antenna book many editions:
Resonance has no effect on antenna performance. The only reason amateurs like to operate an antenna at or NEAR resonance is because the feed point impedance is low so it’s easier to match.
Ray
W8LYJ

Hi Martin,
I do not use any Malware protection on my iPads, but a search for iOS Malware should give you options.

Larry?AC9OX

Sent from Yahoo Mail for iPad

what do you use to scan for malesre in the iphone? i eould like to get a
anti virus scanner

Martin

On Tue, Aug 9, 2022 at 11:23 AM Larry McElhiney via groups.io <lmcelhiney=
[email protected]> wrote:

For those who are most concerned about copyright, one of the links has an
eBook which available at $120. Not sure whether that money goes to pay for
the copy or not.

I download to Files on my iPad and have not seen any Malware issues under
iOS.

Larry
AC9OX

I found a nicely translated datasheet for the 4056 and the temp pin to ground disables temperature monitoring so that's not it. I can't measure anything wrong on the board but it just refuses to charge. It runs fine on the battery although the voltage is now at 3.25v and dropping.

For those who are most concerned about copyright, one of the links has an eBook which available at $120. Not sure whether that money goes to pay for the copy or not.

I download to Files on my iPad and have not seen any Malware issues under iOS.

Larry
AC9OX

Awesome, that schematic looks correct! Its definitely not the cable, theres no current draw when the switch is off but when the switch is on the USB port draws around 300mA but doesn't charge the battery no matter how long the device is left on that way. Essentially, for now, I have to use it plugged into an external USB battery as the internal battery is nearly dead. I'm measuring a dead short on the TEMP pin which I suspect may be responsible but now that I have the schematics I can get a better idea.

Many times when I am looking for a book I type the title in the search bar and put PDF after it and find what I want. Sometimes there is malware. In that case I run a free program called tron. It has allways fixed the problem.
Chris

Sent from Mail for Windows

From: Dan Abell
Sent: Tuesday, August 9, 2022 11:14 AM
To: [email protected]
Subject: Re: [nanovna-users] Smith's book. free download

All, these sources of “free books” most likely contain some current copyrighted material and despite a USA string in the URL are more likely Chinese or other offshore based entities. Just know what you are doing.

Oh and here’s a quote from PCMag: “ PC Matic does install an ad blocker in your browsers, but there's no component to detect and avert malware-hosting URLs or phishing URLs”.

Just saying ...

Dan

On Tue, Aug 9, 2022 at 08:14 AM, David Hilton-Jones wrote:

NanoVNA-F V2

The -F V2 is a Sysjoint product. Thy have their own version of Saver. Download at this link...



Roger

On Tue, Aug 9, 2022 at 08:14 AM, Kyle Claisse wrote:

Does anyone have a link to a schematic diagram for the HW version
4.3_MS of the NanoVNA-H4?

Roger

Some charge cables work and some don't. If you have another cable try it. The cable is likely the issue unless you've used it in the past and it worked with the H4.

73,
Cliff, AE5ZA

Does anyone have a link to a schematic diagram for the HW version
4.3_MS of the NanoVNA-H4? My NanoVNA-H4 doesn't charge (no charge
light and no current flow) when connected to USB. I looked at the
board and its charging IC is an LN4056-H (labeled U2) but none of the
schematics I have found seem use this IC. I am having a hard time
diagnosing the issue without correct schematics. Are these newer
diagrams available publicly?

Thanks,
Kyle

I'm going mad trying to get Saver to load and run.

NanoVNA-F V2
Rev. C
Firmware v0.3.0
Build Aug 2021

Windows 10 - up to date. Running as Administrator

NanoVNASaver.x64
v0.4.0

I download, extract, run as administrator. Black window appears, fills with text, then closes, and then nothing (I've waited an hour!)

No doubt something I'm doing wrong, but what?!

David, G4YTL