Re: NanoVNA_H4 4.3_MS schematics
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.
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Re: Smith's book. free download
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
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Re: NanoVNA_H4 4.3_MS schematics
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.
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Re: Smith's book. free download
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
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Re: Failure to get Nanovna saver to load/run
#nanovna-v2
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
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Re: NanoVNA_H4 4.3_MS schematics
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
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Re: NanoVNA_H4 4.3_MS schematics
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
toggle quoted message
Show quoted text
On Aug 9, 2022, at 02:30, Kyle Claisse <kporgaltmail@...> wrote:
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
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NanoVNA_H4 4.3_MS schematics
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
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Re: 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
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Re: At which point do we take the value of impedance to tune an antenna?
A lot of good discussion here, but I would like to answer the original question from Diane BONKOUNGOU: In my opinion you are not ready to match the antenna. You should bring the antenna to resonance at your desired frequency by shortening it to resonance first, then consider if the SWR is low enough to be finished or you need to match it. Be sure to measure the resonance with the antenna and the mounting the same as it will be in the finished product, metal parts and circuit boards will change the resonance if they change. Circuit board layout is critical at these frequencies. Be sure you have followed the chip manufacturer's layout recommendations EXACTLY in the RF areas of the circuit board, including trace widths and type of components used. Don't use zero ohm resistors as jumpers or to select a test connector versus the antenna circuit, since they are inductive at these frequencies, use SMD capacitors that are self resonant at your operating frequency. What SWR is low enough? Minimum 10 dB return loss or SWR = 2 or less was the value we used for consumer Wi-Fi and Bluetooth at the multi billion dollar company that I worked for. Trying to get it lower would usually lead to losses in the matching components wasting more power than was gained in signal strength.
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Re: At which point do we take the value of impedance to tune an antenna?
Hi, Jerry,
You're right that the lowest SWR may not occur at resonance, whichever definition of
resonance you use. For a particular combination of antenna and transmission line, 1:1
may not be possible as the resistance of the line may not pass through 50 ohms at
the same frequency where the reactance passes through zero ohms.
This may not matter much, if at all, in most cases. If you calculate what happens if you
don't achieve 1:1, but must settle for something "worse," the difference may not be
discernible during actual transmissions.
73,
Maynard
W6PAP
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Show quoted text
On Monday, August 08, 2022 06:00:25 PM Jerry Stuckle wrote: Maynard,
True in this particular case. I was just trying to simplify matters. I
guess I didn't do so well.
My point is that the lowest SWR is NOT necessarily the resonant point.
In fact, very few antennas have an impedance of 50 ohms at resonance.
The lowest SWR may be above or below the resonant frequency.
On 8/3/2022 11:06 AM, Maynard Wright, P. E., W6PAP wrote:
SWR = Zt / Zo applies only when both impedances are resistive. When Zt =
40 + j30 ohms, the load is highly reactive. The coefficient of
reflection rho is:
rho = (Zt - Zo) / (Zt + Zo) = 0 + j0.3333 ...
SWR = (1 + abs(rho)) / (1 - abs(rho)) = 2.0
73,
Maynard
W6PAP
On Tuesday, August 02, 2022 05:26:38 PM Jerry Stuckle wrote:
Incorrect. The VSWR is based on impedance - which is a combination of
resistance and reactance. A vertical at resonance will have an impedance
of about 35 + 0j ohms or an impedance of 35 ohms and a 50/35 or 1.43:1
SWR.
However, slightly off resonance it could have an impedance of say 40 +
30j
ohms, which would have a total impedance of 50 ohms (just an example for
ease of calculations) and an SWR of 1:1. The antenna is non-resonant at
the lowest SWR reading. -----------------------------------------
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Re: At which point do we take the value of impedance to tune an antenna?
Maynard,
True in this particular case. I was just trying to simplify matters. I guess I didn't do so well.
My point is that the lowest SWR is NOT necessarily the resonant point. In fact, very few antennas have an impedance of 50 ohms at resonance. The lowest SWR may be above or below the resonant frequency.
toggle quoted message
Show quoted text
On 8/3/2022 11:06 AM, Maynard Wright, P. E., W6PAP wrote: SWR = Zt / Zo applies only when both impedances are resistive. When Zt = 40 +
j30 ohms, the load is highly reactive. The coefficient of reflection rho is:
rho = (Zt - Zo) / (Zt + Zo) = 0 + j0.3333 ...
SWR = (1 + abs(rho)) / (1 - abs(rho)) = 2.0
73,
Maynard
W6PAP
On Tuesday, August 02, 2022 05:26:38 PM Jerry Stuckle wrote:
Incorrect. The VSWR is based on impedance - which is a combination of
resistance and reactance. A vertical at resonance will have an impedance
of about 35 + 0j ohms or an impedance of 35 ohms and a 50/35 or 1.43:1 SWR.
However, slightly off resonance it could have an impedance of say 40 + 30j
ohms, which would have a total impedance of 50 ohms (just an example for
ease of calculations) and an SWR of 1:1. The antenna is non-resonant at
the lowest SWR reading.
-----------------------------------------
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Re: At which point do we take the value of impedance to tune an antenna?
VSWR is measured in voltage but the cause is the difference in impedance (if there is one) between two items - in this case the feedline and the antenna.
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Re: At which point do we take the value of impedance to tune an antenna?
First of all, there is no SWR of 1:2. SWR is always X:1.
And a 50 ohm cable feeding a 50 ohm load is by definition an SWR of 1:1.
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Re: Smith's book. free download
For those that don't like strange download sites, the book is now on archive.org
Give the page a couple of hours to populate all the options. The pdf is available now, in browser read later.
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Re: Modify Original Nanovna for easy DFU mode like the H4
#dfu
#mods
On Wed, Jan 22, 2020 at 03:03 PM, Larry Rothman wrote: - Change R5 to 1K ohm (same as H4) One remark regarding the -H versions: If you look at Hugen's schematics, you will see that R5 has the same value of 1 kOhm as for the -H4 version. Therefore Larry's modification can be simplified. No need to change R5, just add one wire from P1/BOOT0 to the centre pin of the jog switch and you are on the very safe side regarding the HI potential.
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Re: Smith's book. free download
I have a collection of maybe a dozen Smith Chart variations that I keep as masters to make copies/scans as needed.
73, Don N2VGU
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Re: Smith's book. free download
One alternative that I use is the software, 3D Smith Chart: 3dsmithchart.com. Inexpensive. No color crayons necessary, ?
Frank
K4FMH
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Re: Smith's book. free download
Justin,
If you follow these things enough, sometimes with the more difficult to understand first, make the later simpler explanations just pop out at you and make sense. There is no wasted perusing of all this stuff we have access to. Keep perusing on¡..
Dave K8WPE
David J. Wilcox¡¯s iPad
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Show quoted text
On Aug 7, 2022, at 11:55 AM, Justin Bowser - KI5GKD <justin.bowser@...> wrote:
?TNX, just downloaded it. Pretty hefty PDF @ 21 MB!
Not sure I'll understand anything in it... :-\
73,
Justin B.
KI5GKD
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Larry McElhiney
Roger Need
Ho-Ro
Donald S Brant Jr
Frank K4FMH
David Wilcox K8WPE