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The NanoVNA doesn't have a separate Source and receiver ports, so you can't do the external amplifier, coupler approach in the Rackley paper. Is there a reason you need high power for the test?

The NanoVNA doesn't have a separate Source and receiver ports, so you can't do the external amplifier, coupler approach in the Rackley paper. Is there a reason you need high power for the test?

From amfone :https://amfone.net/Amforum/index.php?topic=37502.0;wap2 John K5PRO: Before the days of plastic antenna analyzers, you either used a GR bridge or a slotted line (for VHF), or just knew

Thanks Jim, now I understand better. So, I will build a LC tuning circuit and I will measure afterwards to adjust it. -- 73 s Christian F8GHE

I've added impedance measurements to the S-parameter plotter. It now includes the one-port reflection method and the two-port series-through, shunt-through, and Y21 methods. Y21 cancels stray port

Roger, Thanks. I thought I had replied yesterday but apparently not. Well, let me shop some 0603 resistors and ferrites and I'll come back once I get something decent. Also, my board is scrap. 1-

Some of those techniques are more about measuring a high impedance component, so they wouldn’t work. You’re making an S11 measurement - it’s just challenging because for end fed antennas,

Jim thanks very much for your advise. During this afternoon I found these urls and now I don't know what is the best way to measure my end-feed antenna : Your or one of these : -

Also ensure that the cable that you are using is a data cable and not just one capable of only supplying power. Many cables can only supply power unless specifically stated, so I use a cable tester to

NanoVNA Saver does not touch your firmware so it could not have damaged your device. Your device cannot be "bricked" because the DFU loader is built into ROM on the microprocessor. Does your device

Nico, You mentioned that you are just starting off with RF design. You have picked a difficult starter project because at 900 MHz. there are many factors that come into play that are not big issues

Mine is not seen by Win 10 device manager. ( tried 2 cables and machines) I heard there is a way to get it out of DFU mode internally? Mine did not die updating firmware, but it was hooked up to PC

The feedline is still part of the antenna. The best you could do with this setup (the first image) is to decouple immediately after the SMA connector (ideally before the connector). 61 or 52

One way might be to use a transformer. ?Minicircuits has small, inexpensive transformers in a DIP package in ratios up to 16:1 or 25:1. 1:25 CORE & WIRE Transformer, 0.02 - 30 MHz, 50? |

Hi, Currently trying to design and tune a 1/2 end fed antenna (RF is applied on one end), I am looking for the correct method to measure its impedance. As this one is very high I don't know the right

I recently wrote a program to renormalize S-parameter impedance. This lets you measure a filter with a 50 ohm VNA even though the design impedance is higher. In the course of testing the program, I

Wow ! Thank you so much to every one for taking your time in helping me. I truly appreciate it. @Siegfried @John I finally did it. I've cut down my RG174 down to the shortest length I could (35mm).

And also remember line lengths on/in the dielectric are shortened by the reciprocal of the SQRT of the dielectric constant (I assume FR-4?....nominally 4.2). Dave -

Nico, A couple of points to consider. 1. I can't tell from your PCB photo if you had tracks on both sides of the board in order to implemented a transmission line from the matching network to the

I don't know that shortening it even more makes all that much difference. You can guestimate the loss and to a first order, you're looking for reasonably flat S11 across your band, right? So if 174