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On 12/5/21 9:43 AM, Nicholas wrote:

For some strange reason my NanoVNA is now not responding correctly to any antenna designed for the AM broadcast band and instead is showing it as an open. I have confirmed the calibration using the test loads and it looks perfect so I am not sure what is going on here.

Could your antenna be picking up significant amounts of signal and overloading the input of the VNA?

For some strange reason my NanoVNA is now not responding correctly to any antenna designed for the AM broadcast band and instead is showing it as an open. I have confirmed the calibration using the test loads and it looks perfect so I am not sure what is going on here.

On 12/4/21 6:59 PM, Nicholas wrote:

One big reason why I got the device is to determine an unknown impedance on a transmitter and to adjust it to 50 ohms to drive antennas better. What method would I use for that, the transmitter by the way is a part 15 compliant AM one built from a kit with a maximum output of 100 mW and a continuously variable output control from 0 to 100 mW. This has been bugging me for quite a while but I have found the device very useful for looking at antennas.

it is? difficult to measure the output impedance of a high power amplifier (S22) in a meaningful way, because it really means you are feeding a signal into the output (like a salmon swimming upstream).? And it's not clear that that's the measurement you want.

One way to do it is to measure the output into varying loads (generically, called a load pull measurement), which you could do with a NanoVNA, and some sort of output coupler. From measuring the output signal with different loads, you can calculate the output Z.

Consider the amplifier as a Thevenin equivalent of a ideal voltage source in series with a output impedance Zout. The output voltage of the amplifier (which is what the VNA measures) is Vout = Videal*Zload/(Zout+Zload).? So if you measure the Vout with a couple or three Zload, you can calculate Zout.

I think the question was about finding Zeenko's store, so here is the link:


On Fri, Dec 3, 2021 at 9:49 AM 贵é濒颈虫 ?ngel <felixangelperiago@...>
wrote:

Hello Erik.

Zeenko's NanoVNA H4 is not a good NanoVNA?
I have a Nanovna but i want to buy an H4.

Regards
贵é濒颈虫

El vie., 3 dic. 2021 12:16, Erik <dl1ecd@...> escribió:

Looking for an approved vendor Aliexpress (Zeenko Store) without success.
Where to buy a NanoVNA H4 HW rev 4.3?
--
73 de dl1ecd, Erik

One big reason why I got the device is to determine an unknown impedance on a transmitter and to adjust it to 50 ohms to drive antennas better. What method would I use for that, the transmitter by the way is a part 15 compliant AM one built from a kit with a maximum output of 100 mW and a continuously variable output control from 0 to 100 mW. This has been bugging me for quite a while but I have found the device very useful for looking at antennas.

On Sat, Dec 4, 2021 at 06:38 AM, Ralph Bolt, K?RO wrote:

I understand how to use the Nano-VNA to measure a crystal's frequency.

Can I use the same configuration to measure the resonant frequency of a
parallel capacitor and inductor?

There are several ways to measure parallel L/C resonance with a VNA. Some are described half way down in this article.



Roger

Here is an excellent video that shows you how to use a NanoVNA-H/H4 to measure crystal parameters.



Roger

You were asking about fw for SYSJOINT and that is their official group. Whatever. Rewrite the firmware from scratch for all we care ?

Sorry, not V2...

On 12/4/21 6:35 AM, Ralph Bolt, K?RO via groups.io wrote:

I understand how to use the Nano-VNA to measure a crystal's frequency.

Can I use the same configuration to measure the resonant frequency of a parallel capacitor and inductor?

yes, and it's a lot easier, because the LC circuit is lower Q, so you don't have to worry about "missing" the resonance with only 101 points.

I understand how to use the Nano-VNA to measure a crystal's frequency.

Can I use the same configuration to measure the resonant frequency of a parallel capacitor and inductor?

Am Samstag, 4. Dezember 2021, 15:02:55 CET schrieb Hugen:

You can buy NanoVNA-H4 from the zeenko store. NanoVNA-H4 is now sold by
zeenko in version rev4.3.

Thank you for instantaneous response.

Erik, DL1ECD

You can buy NanoVNA-H4 from the zeenko store. NanoVNA-H4 is now sold by zeenko in version rev4.3.

It should be noted that the MCU used in the NanoVNA-H4 rev4.3 is the STM32F302CBT6. We have tested that the STM32F302CBT6 has the same RAM and ROM as the STM32F302CCT6.
Since no additional STM32F303 functions are used on the NanoVNA-H4, the STM32F302 and STM303 use on the NanoVNA-H4 are identical.

I am just finding this info about the V2plus4 and it’s locked down boatloader and fw author not willing to add ability to disable temperature compensation when CW mode is selected.

So is there no hope other than to try and buy a different V2 variant and sell this one ?

In the absence of solutions I have returned to the original Firmware. With it I can manage my NanoVNA from the PC with the usual software (NanoVNA-App, NanoVNA-Sharp, NanoVNA-Server).
Too bad not being able to enjoy the 401 points and manage it at the same time from the PC.

Thank you all.
Antonio - EA7HJ

Thank you for the info, Jempi. But is this firmware version the correct
one for my nanoVNA-F (not V2!) by sysjoint?

Hi all.
On amazon.co.uk I bought a NanoVNA from AllAboutFun. It had the STM32F302 chip. I contacted the company and in their reply they said

According to your question, we have communicated with the supplier.
This is an open source product, and the STM32F303CCT6 chip is currently out of stock.
We will definitely only use STM32F303CCT6 in the future.

I returned it to amazon and was refunded.

I then bought this one for ?114.18
Nooelec NanoVNA-H 4 Premium Bundle - Vector Network Analyzer Kit from Authorized Distributor with 50kHz-1.5GHz+ Portable VNA (4" LCD), EMI Shielding, Calibration Kit, 6pc Attenuator Kit and Much More!
Brand NooElec

It arrived this morning and I can confirm it has the ST32F303CCT6 chip in it.

I hope this helps UK users.
Colin MM5AGM

HI, Pse Check



Latest version 1.0.3 Sep 9-21

Suc6

JP

Hello Erik.

Zeenko's NanoVNA H4 is not a good NanoVNA?
I have a Nanovna but i want to buy an H4.

Regards
贵é濒颈虫