Re: Stimulus Span change a bit the Smith measurement
Interesting calculation, Jim. Your conductive tube is very descriptive, It points out that when designing an inductor, one should use the biggest wire that is consistent with the mechanical problems
By
Bob Larkin
·
#39358
·
|
Extra QEX copy
Does anyone want a copy of the January/February 2025 issue of QEX? The ARRL sent me two copies. It has the tinySA tracking generator design article in it. Of so *respond to me privately* at kc0wjn at
By
Dave Daniel
·
#39357
·
|
Re: H4 Firmware update error
NanoVNA App need use DFUSe driver for device in DFU mode, by default windows install driver for STM32CubeProgrammer (this driver allow flash in this software, but not work for NanoVNA-App or
By
DiSlord
·
#39356
·
|
H4 Firmware update error
Tried to update my H4 with the app and got this error: Opening \\?\usb#vid_0483&pid_df11#206a31562031#{a5dcbf10-6530-11d2-901f-00c04fb951ed} ?open failed Device Manager shows NanoVNA-H4 is connected.
By
Mark Jordan
·
#39355
·
|
Re: NanoVNA-H4 number screen malfunctioning
Before re-installing firmware, I would try a 'clear config' (under expert settings). That will help reset internal parameters, in case something amiss there is affecting this. Regarding new firmware,
By
Stan Dye
·
#39354
·
|
Re: NanoVNA-H4 number screen malfunctioning
As it should! Dfu is *NOT* a COM port, and requires it's own driver which is provided with the app of your choice. -- Sent from my Android device with K-9 Mail. Please excuse my brevity.
By
Tim Dawson
·
#39353
·
|
Re: NanoVNA-H4 number screen malfunctioning
I can't get the device to connect with a Windows computer in DFU mode. I can connect in normal mode with COM4. As soon as I put the device in DFU mode it disconnects and COM4 disappears from Device
By
Steve Johnson
·
#39352
·
|
NanoVNA-H4 number screen malfunctioning
I have a NanoVNA-H4 which has been working for months. Today I needed to test a broadcast band filter and when I try to enter any number on the number screen (for setting stimulus start/end etc.) the
By
Steve Johnson
·
#39351
·
|
Re: SWR readings change when NanoVNA is held
Hi Coyote, As others have already mentioned having a good choke on the feedline is the key. When operating mobile (40 and 20 meters) with a ham stick or hustler mobile antenna I use approximately 9 of
By
Donald Kirk
·
#39350
·
|
Re: NanoVNA update
Thanks for the well-worded clarification Stan. I think I¡¯ll go with STMCubeProgrammer since I already have too many other custom drivers installed for FPGA tools and dev boards. Tony
By
Tony Scaminaci
·
#39349
·
|
Re: TDR maximum length NanovnaH4
very long... It's driven by the lowest frequency in the sweep, which is something like 50 kHz. You want the thing being measured to be less than half a wavelength long. So 50kHz >> 3km.
By
Jim Lux
·
#39348
·
|
TDR maximum length NanovnaH4
Hello, has anyone measured or knows what is the maximum length that nanovnatdr can measure NanovnaH4
By
mamafu546@...
·
#39347
·
|
Re: Stimulus Span change a bit the Smith measurement
This isn¡¯t too far off from what you¡¯d expect just from the difference in diameter of AWG22 and AWG 26 wire ( 644 and 405 microns) - the Skin Depth at 14 MHz is about 17 microns, so they¡¯re
By
Jim Lux
·
#39346
·
|
Re: SWR readings change when NanoVNA is held
To state the obvious, the feed line and termination are, in this case, part of the antenna. In some cases an advantage, but not for reliable measurements of an antenna. Lester B Veenstra K1YCM M?YCM
By
Lester Veenstra
·
#39345
·
|
Re: NanoVNA update
You use the DFU file with DfuseDemo You use the bin file with STMCubeProgrammer (current downloadable version) I think either version works with nanovna-app (but I don't remember for sure). DfuseDemo
By
Stan Dye
·
#39344
·
|
Re: SWR readings change when NanoVNA is held
Thanks for all of the responses and the assistance. I haven't tried again, but will soon. I did put a choke on, and it greatly increased my SWR ---- hmmm. I'm encouraged from the responses. I thought
By
Coyote
·
#39343
·
|
Re: NanoVNA update
Stan, I have the same unit as Richard, v4.3-MS. Is dfuse the best way to update to 1.2.40 or is it better to use the .bin file? Also, I was under the impression that there were two versions, one for
By
Tony Scaminaci
·
#39342
·
|
Re: SWR readings change when NanoVNA is held
Can only imagine from whence DJ0IP lifted the drawing with his name on it, given the difficulty he has supporting his ¡°material¡± to an original source. Maynard¡¯s diagram certainly covered the
By
AG6CX
·
#39341
·
|
Re: SWR readings change when NanoVNA is held
Hi, Roger, That is a good diagram. Thanks for pointing that out. 73, Maynard W6PAP
By
Maynard Wright, P. E., W6PAP
·
#39340
·
|
Re: SWR readings change when NanoVNA is held
Maynard - Thanks for drawing. Here is another one that illustrates what I was posting. It is from this site -->> https://www.dj0ip.com/Common_Mode_Current
By
Roger Need
·
#39339
·
|