开云体育

There are a multitude of forum messages that detail how to flash the DFU file in Linux. It's also mentioned in the various user guides in the forum files area. A quick search of messages using search

glad you've got it sorted. BTW, is there any DFU tool on linux?

Thanks to all, many thanks, Now i perfectly understand everything. I will try everything you told me this week end ! And i love the idea of the TV rabit antenna ! Have all a great day !

Hi Mike. You will need to construct a bias Tee. A shunt choke to feed supply to the amp on the output port with a series C for a DC block to CH1 of the vna. If there is a DC block internal to the

Can someone suggest a setup including isolation caps and chokes to test an HF wideband (1.6 MHZ to 28 MHz) pre amp that is used to match a single vertical 17 feet tall to 75 ohm coax. The preamp is

I use 1 uH/meter, which is somewhat larger, but the right general magnitude.? Inductance doesn't vary very quickly with diameter or shape, it's all about length and whether there's coupling from one

There is no doubt, today, parallel conductor transmission lines are neglected. It was the first xmsn line we used following the spark days. No doubt coaxial cable is install-and-forget-it, especially

A number I've always kept in mind for AWG #18 enamelled single conductor copper wire: 18.1 nH / inch. Dave - W?LEV -- *Dave - W?LEV* *Just Let Darwin Work*

I just did this (unintentionally!) on my NanoVNA Mk1 and can confirm that the instructions re entering DFU mode in the Windows guide are correct. (I'm using linux.) After the jumper connection is

Thanks Gyula! I updated the firmware and cleared the config as you described. That may have been the ticket, but too early to tell just yet. I also have two new firmware to experiment with! Using the

I did the same thing just a bit ago, but with a different firmware. I was able to shut down the NanoVNA (wait until the light goes out), short the two pins, power back on. The USB bootloader was once

I do not think the importance of this can be understated. 50 Ohms has always been a nominal, not exact, goal for system design. The efforts to modify the manufactured tool to get the port impedance to

*Dave - W?LEV* The ARRL Antenna Handbook ladder line nomograph that shows spacing versus wire size I have been seeing in ARRL publications for the last 55 years licensed. I agree it does not take

Just something to consider. Think about the shunt C of 6 resistors in parallel. There might be as high as 0.5 pF per resistor. I measured axial lead resistors with my old HP (BRC) 250 RX meter

It kind of depends on what you're trying to measure. If you're confirming S11 for the design, then a ground plane works great - you model it over a ground plane, build it, and see if it matches the

Hi Matt, After a firmware upgrade, all previous data must be deleted from the device storage to prevent it from being used. Therefore, after updating the firmware, use the 'clearconfig 1234' command

My approach is to attach the antenna to the NanoVNA to mimic the handie-talkie as best as possible. Hold the VNA as you would a radio and make your measurements. A rubber ducky on a ground plane is

Hello Pierre, Yes, what the others have said, your hand changes the loading on half the antenna, both with HT and Nano. If your goal is max range mountain-topping, you can easily make a much better

I'm probably one of those rare birds who actually uses twin-lead VF and Zo. There's about a 30 foot run of coax from where my doublet's window-line terminates on an outside wall of the house to the

The coax braid/ground is connected. I should elaborate that I see higher than normal readings when testing many different antennas. I just tried flashing back to the 0.7 firmware and get the same