开云体育

Alan, The schematics are in the Wiki. There are only resistors in the input pad. You need to measure them to see which is fried. Hopefully, you didn't fry the SA612 input. If you have 2 soldering

So S21 has been damaged when I was checking a LNA, i gapped it for 2 seconds and hooked the attenuator on the wrong side. It is a H4, I was going to order a new one as needed pass through on most

I'm not sure a USB cable would make a difference if the feedline is properly "isolated" from the environment. (i.e. the USB cable isn't coiled up with the transmission line). I can't think of a

Sorry - that should be 3v at each of the points, not between. Now, with that said, I just had weirdness with my Nano-H - it wouldn't boot. It turned out the Enter button (I installed buttons on mine)

I measured it while unplugged from USB, I get 3.4V between VDD and Ground but no voltage between VDD and the capacitor in the picture.

The only thing at this point is to measure the VDD out of the 3v regulator to make sure it's working. Schematics are in the Wiki.I've attached an early H4 PCB image for you.

Your battery is defective - get a new one or have a look at some of my early posts where I used a cellphone battery. /g/nanovna-users/attachment/223/0/Battery-PCB-MiscShields.jpg

my nano vna Hugen v4 shows full battery but after about 10 seconds turn off.... connected to USB port works fine wrote:

Sorry should have been clearer, it doesn't turn on even with the battery disconnected.

Correct - that is controlled by the charging/inverter chip. Can you turn your Nano turn on when connected to USB and the battery is disconnected?

Hi Larry, When I disconnect the battery and plug the USB in the LED blinks as if it is charging. sorry for double post, didn't realize my other one went though.

Just make sure, as others have pointed out, that you don’t have any other wires (power supply, USB to computer,, etc) connected to the nanoVNA. 73, Willie N1JBJ

Considering that the NanoVNA is smaller than a lot of HF baluns for balanced lines, I don't think you need the balun, either (until you get up to where the NanoVNA is a significant fraction of a

On 2/16/22 11:28 PM, Bob Ecclestone VK2ZRE wrote: > I'm wondering if the correct way to measure the length of window line > with a NanoVNA is fundamentally different than that of measuring coax. > >

We're measuring impedance here. No matching transformer is needed. Just a 1:1 high common mode Z balun. From the Z's measured you determine the characteristics of the balanced transmission line OR and

Hi Brady, Did you try disconnecting the battery and powering the Nano from a USB source? Sometimes when the battery gets too low, the CPU can get into a weird state (assuming you have the battery

Hi All, My Nano VNA-H4 was sitting for a while, and after charging will not turn on. I checked the battery voltage, it is fully charged. The red LED works, not sure what to do next. Any help would be

Agree with Kevin. Very good explanation. John, wa3jrs

Bob, thank you so much for your very detailed answer. It'll take me awhile to get the ferrite and build the test jig, but I'll let the group know of my results. Thank you, again, for so generously

I have the same looking unit with the same firmware. It says it is supposed to go to 3ghz but mine only allows 2.413ghz as top end. Have you tested yours to 3ghz?