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What frequency range are you calibrated for? Perhaps recalibrate for a narrower range spanning the AM broadcast band, say 200 kHz to 2500 kHz.? Good luck.

Ken - WB?OCV

Those creations will likely work adequately for HF frequencies and below.
But at VHF and above, the leads and composition of the resistors will cause
some issues due to the parasitic inductance.

I checked it elsewhere and it does not seem to be responding at all below 50 MHz so it is not just the AM broadcast band but also HF and to an extent low VHF as well.

try these out,, i too have been trying to get better cal kit just for the nanovna, i made set of
so239 (see my post "Calibration, Compensation, DIY Parts Hacking!...... My First Post!") and i think
its ok but i still want to order these( ) and see if my tinkering is ok, plus having a factorie cal set will let me build more stuff knowing i have more then one standard to rely/test on on.. good
luck
KK6DBR

Thanks for a great reference, Roger. There's much to be learned in that video.

73, Ralph Bolt, K?RO

Thanks Jim. I tried it with good success.

73, Ralph Blt, K?RO

It was working perfectly in the AM broadcast band before both the S21 and S22 connectors so I don't think that is the problem. The nearest AM radio station to me is about six miles away and I am using the upper edge of the band but that is a reasonable possibility.

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.