开云体育

Thanks a ton guys! have some 50ohm for dummy loads I planned to build, will use and report.

Hi Larry,

Thanks.

I have one from the first batch, I am used to upgrade.

And it's so easy to go into dfuse mode...

Newer FW versions add functionality and/or correct errors.
Any FW version from the beginning of 2020 will do and they are easy to flash into the device.

Thanks, but sorry I did not get if you answered my question: best fw for nanovna-saver

Cheers and thanks

Thank you
it seems I am too late...

Chris

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'Everything should be made as simple as possible, but not simpler.' -- Albert Einstein

Am 24.03.2020 um 11:23 schrieb CT2FZI:

On Tindie you can pay with Paypal. In my account I can use it for paying...

Chris

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'Everything should be made as simple as possible, but not simpler.' -- Albert Einstein

Am 05.03.2020 um 21:27 schrieb Larry Rothman:

The nanovna saver is not currently being developed
because of the busy programmer.
Latest Version: 0.2.2.1 (Python 0.2.2)


The 2.8-inch core nanovna edy555 version 0.7.1-20200321,

while the Hugen version is 0.4.5-4.
beware, because here you can find the version of -H4 you need -H


Otherwise, check out the Wiki folder.

Hi everyone,

From all the firmware versions for the nanovna-H (original) what firmware do you recomend to take the most from the nanovna-saver?

Or, is the nanovna-saver agnostic to fw version?

Cheers and thanks

Howdy Pablo! This virus should has thrown the world into turmoil... I hope it turns out to be a minor virus, not as bad as the flu.
As far as coax for antenna for an H/T, I would assume around 145 MHz and/or 445 MHz for ham bands?

I use a good quality RG-6 for my scanners. This is of course adding in a 1.5:1 SWR but due to being used receive only, it's of little consequence.
I have 800 MHz trunking systems I monitor as well as low band VHF (45 MHz) and the coax I swept is pretty wide band and low loss. I have multiple scanners so I use a small CATV distribution amplifier. Each port is 7 db gain so it compensates for coax losses. I have under 20 meters going to a discone antenna. The amp does provide a bias-t function so i could use an LNA at the antenna....the one I have is 17 db gain but I don't need it. My scanners all have BNC antenna connectors so I use a BNC-F adapter and then about .7 meter pigtails of RG-6 from the amp to the receivers. It all appears to work well.
Food for thought or maybe excess information....

73 de Tim, K4SHF

Hi Roger,

Thanks for this, your results look very similar to mine, there is a slight difference in the frequency of the dips but I assume this is due to differences in the mix of the core material, winding pattern (causing a difference of capacitance between turns) and also stray capacitance and inductance on connecting wires.

The images below show my results of two back to back 1T to 8T impedance transformers using BN73-202 binocular cores with plastic insulated wires compared to yours (mine look just like the ones in the photo you attached, they are wound in exactly the same way). I have added your images next to my results for comparison, mine are the left ones and yours are the right ones.

I am pleased my results match so closely to yours - it is always helpful to be able to compare results.

Thanks for taking the time do do this.

Tindie out of stock - I have purchased their last unit :)

Kerr,

I wound two 1T to 8T impedance transformers using BN73-202 binocular cores and insulated, solid, silver-plated wire-wrap wire. They were connected back to back and the 1T sides soldered to SMA connectors as shown below. NanoVNA Saver was used to make the measurements from 1 MHz. to 30 MHz (plots below). The worst case S21 loss was 5.9 dB at 30 MHz. (back-back) which is about 3 dB for one transformer. In the 40M band the S21 was -2.69 dB (back-back) or -1.35 dB for one transformer which is quite good. Return loss (S11) varied from 12 dB to 3.71 dB across the 30 MHz. test range.

There is enough room in the core holes to wind 2T to 16T but I have not done this yet.

Pablo you can also take a look at this video that is very detailed on how to determine the impedance and velocity factor of any unknow coax cable:

Saludos Pablo,

You could use the TDR function of the NanoVNA to check the impedance of an unknown coax cable by soldering a non-inductive variable resistor (value within the range of the suspected cable impedance) at the far end of the coax cable. Normally if you leave the end of the cable open circuit you will see a reflection due to the impedance mismatch. Vary the value of the variable resistor and once you see that the reflection is gone you know that the resistance that the variable resistor is set to is equivalent to the cable impedance. Just measure the resistance of the variable resistor with a DMM and you're good to go.

Hope that helps.
Alex

Had exactly the same DANG here. Totally loose display and connector broken.

I was able to resolder the display onto the pcb. Took me 5 times of trying but I succeeded :-)

Give it a try.

73,

Arie Pa3a

50 or 75Ω, it shouldn't make a big difference unless you are wanting to push high power through it.

Try these:

/g/nanovna-users/topic/69269493

Hi guys and greeting from Buenos Aires, Argentina. We're in full country quarantine since thursday, I was planning on buying some cable, but our govt acted so fast that I had no time, so I'm stuck at home with a couple of rolls of coaxial cable and wanting to improve my external antenna for my HT.
Have a Hugen VNA with Eddy 0.7 firmware but still don't trully know how to use it besides basic stuff.
They are probably 75ohm but from photos I found on the web some may actually be rg58, can you guys tell me how to use nanoVNA to know the cable impedance?

Thanks

Gyula wrote:

You will then need to use the ST-LINK utility with the following memory
parameters:
- Address: 0x08000000
- Size: 0x20000
- Data width: 8 bits
It seems that on MAC OSX, ST-Link is available with the terminal program, so
the .bin file can be uploaded - no need to convert .dfu.

Guyla, correct, no need to convert to .dfu, but dfu-util can update with the ch.bin file.

It is not necessary to install STLink (at least in 10.14.6), but is there some other benefit to installing it?

BTW, since Homebrew was originally used to install dfu-util, I could install STLink like this:
brew install stlink

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I_B_Nbridgema

Oh, I really hope we will not be disappointed by Gabriel's little baby. I'm waiting too long already...
Less noisy I hope at 900 MHz than VNWA and NanoVNA and finally 2.4 GHz!
Reinier