开云体育

On Sun, Jan 5, 2020 at 08:04 PM, Gary O'Neil wrote: Hi Gary, I don't know if I can answer your questions, but let me start with the last ones... > > This brings up yet another question. If the devices

You might try rapping the connectors on the ends of the line and check for any changes in S11 or S21 response. S21 loss should be less then -0.5 dB @ 30 MHz for 350' of 1.25" hardline. If connectors

I hesitate to jump into this, but... The "correction coefficients" that professional VNAs apply to compensate for, e.g., fringing capacitance in the opens, are not just electrical measurements of

Hey Allison, Thanks for the hints. Any idea on the referenced books? Thanks, Adrian

Hi Gabriel, MiniCkts and Toko will build whatever you want - it all boils down to how much you're willing to pay... ...and yes, for a short manufacturing run like this, it's not worth it. Unless... If

I missed what was actually being tested.... Also, if one is testing cables themselves, is there a finite distant limit? BR Tim K4SHF

Good to hear that better symmetry is a solution. The problem with tuning as you do now is that it is frequency dependent. Maybe you can try to increase the pcb trace length to compensate for the

Robert, It would be desirable if you could also measure the transmission through the cable, including both magnitude and phase versus frequency. Plus any info you have about the supposed

On Sun, Jan 5, 2020 at 08:57 PM, <hugen@...> wrote: English translation with the help of "Microsoft Translate" ….. Please forgive me for replying in Chinese. The GD32F303's cheaper price and

Here's the pdf:

はぁ (ha), that did the trick. I did the surgery on only one leg so there is still some imbalance, but the directivity improved from 8dB to 16dB, on par with the performance with tuning (see

The S11 plot is attached...not pleasing at all. VNA measurements require phase stables cables. The ones I use for microwave use (upto 26.5 GHz) are 24” long and cost $5000 a pair. The changes in

Hi Peter, go to my website and read more about this topic (ha3hz.hu) 73, Gyula HA3HZ

Hi Gabriel, As an experiment, you could try to make a more symmetrical balun by placing the core vertically over the pcb and making sure the wires have equal length. Another request, could you publish

From: Robin Midgett I've calibrated my NanoVNA & connected it to an approximate 350' length of coax with a known good dummy load on the opposite end. The S11 plot is attached...not pleasing at all.

For an N connector, the seller must have an adapter option with a calibration kit. My counterpart. It is very convenient to work. And the BNC option should be similar. It solves many technological

Please forgive me for using Chinese reply.

Hi Jeff; Per my post: @ Gary O'Neil - /g/nanovna-users/message/9184 I don't find any source of disagreement in your posts: @ Jeff Anderson -

Thanks Dave, I'll try that soon..hopefully tomorrow evening.

Hi Clyde, Thanks for the quick response. Here's a plot of the dummy load across the same span....looks good to me, but I'm here to learn from others. I haven't tried VNA Saver yet...would have to