开云体育

This is a good argument if you are well versed in antenna analysis and really understand the capabilities of the MJF 259 family, nanoVNA, and others. I have owned and used the MFJ and nano but when

It really would be better to have the two cables for any two port testing you perform, as they are. Mark them too just to be certain. And for your testing of the Antenna, Have a third cable that you

Alezis, Try running a Calibration if you haven't done that already. I am not sure that will deal with all 3.4 vs 3.1 issues, but it should get traces on the screen unless the configuration settings

Hello everyone, a friend came by to update his nanovna. It is a black nanovna and the QR code redirect to nanovna.com which leads to this forum. So I did pick the latest hugen firmware and the update

MFJ sells some products that claim to be VNAs: https://mfjenterprises.com/products/mfj-223 https://mfjenterprises.com/products/mfj-227 https://mfjenterprises.com/products/mfj-225 Only the last of

Dave, I'm not arguing. I am discussing the statements about the MFJ-259 and the NanoVNA. The 259 does not claim to be a VNA ("The NANOVNA's come *far* closer to the HP 8753C capability than the MFJ

I am not going to enter into a tit-for-tat argument. My statements addressing both the MFJ and NANOVNA's come from experience of using both products. I confess, I'm spoiled by years of use of the HP

I'd done a brief check before posting, evaluated the impedance at w=sqrt(1/LC). Saw zero reactance there and assumed I was done. Guess I was wrong! Thanks for the puzzle. Jerry

I've had an MFJ-259 for about 30 years. I use it primarily for adjusting the length of dipoles and low-level tuning up of my antenna tuning units, the main one being an MFJ-969, but I have a few

[email protected]> wrote: The circuit is more a curiosity than anything else. But it hopefully gets people away from the belief that the resonant frequency of a parallel turned is independent of

[email protected]> wrote: The resonant frequency of a parallel tuned circuit does depend on the resistive losses, but for a series tuned circuit it does not. I believe that all the books aimed at

I don’t know how to do it on my iPhone. I use the gmail app. Someone worked it out. The result is that the impedance is real at all frequencies, so you could argue it’s resonate at all

[email protected]> wrote: That’s true for series connected devices, not parallel. As someone has shown, the impedance is purely real at all frequencies. G8WRB Dr. David Kirkby, Kirkby Microwave

Hi Larry, Yes, I've used that page from Tom. It is more complicated that the NanoVNA for sure....He was an MFJ contract employee for years but stepped away just a few years ago. I used his guide to

Please read the messages in this thread to answer your question.

Do you have experience with MFJ-225. How is it compared to NanoVNA? -- 73, Pedja

I was curious about what was involved with calibrating the MFJ259 - so I did some searching and found this webpage: https://www.w8ji.com/mfj-259b_calibration.htm It appears to be quite involved job

Hi Bob, Very well articulated statement on why the NanoVNA is the preferred tool for you. I'm delighted that you've learned what it can do for you. It's clear though that only a smaller share of hams

Hi Dave, Did you calibrate your 259 and did you buy it new? I can tell you from many customer service calls to MFJ that many complaints arrive from customers who purchased the 259/269 units used. The

By "standard definitions" I mean the correct values of delay, C0, C1, etc to use for a specific open or short ("calibration standard"). The question is not about how coefficients like C0 are defined.