开云体育

Hi OK, but from the table I can't see the feedback multisynth divider ratio. Indeed above 150 MHz the output multisynth divider ratio is fixed at 4 per Si5351A datasheet. Bo

Jim, according to the AC (RF) maximum power transfer theorem, you get maximum power transfer when the load impedance is *conjugately* matched. Luckily, coax with a Z0 of 50+j0 ohms is a trivial

Ken, You hit the nail on the head. At low frequencies, at VHF and down, I wouldn't worry about picosecond delays or femto-farad fringing C's. And I bet 99% of the Nano users will be looking at SWR

KE8CPD, The group firmware repository below might be your best bet for locating the old firmware. Try the hugen or edy555 folders.

Going from your picture, it looks like the calibration didn't "take". In your picture of 50k-900M span, 50k-300M looks right, and the rest just looks weird. So I would expect it to be that you need to

Ok so the issue stemmed from trying to use it with Nano-saver, and got a error (see below)(info: this is only two lines of what it spit out). 2019-10-13 08:38:17,772 - NanoVNASaver.SweepWorker -

Yes, I did send him my code . Its tested now and works well

See attached table for what frequencies are used when. The SI5351 library is from edy555 Above 100MHz the SI5351 is used with either 6 (between 100-150MHz) or 4 (between 150-300MHz) as final divider

Hi As long as the fundamental frequency of the Si5351A is without significant error vs the theoretical frequency there is no practical difference even on a fifth harmonic. Frequencies in the Si5351A

But higher frequency offset may leads to worse frequency resolution, isn't it? Can you give me the required changes in firmware? I will test it on 500 kHz electromechanical bandpass filter, it has 3.2

Erik, try to measure it with NanoVNA disconnected from external power. And then measure it with external power applied (through usb cable). You will found that there is very high error from 900 to

No. All internal calculation are exactly the same, luckily there was sufficient headroom in the data types being used You always should calibrate with the frequency range you want to use for the

To provide some evidence the nanoVNA is actually usable till 1500MHz here I have a measurement of a 25 ohm resistor at the calibration plan from 0.5MHz till 1500MHz Of course performance decreases

edy255 is adding to mainstream firmware: https://circleci.com/gh/ttrftech/NanoVNA/115

I think the term “vector voltmeter” in the FieldFox is a bit deceiving, given the hardware called vector voltmeters have been available for years - I used one for my final year project as an

does it makes frequency resolution more worse?

This extension to 1.5 GHz is certainly of interest to some hams in the UK. One of the hams in our club, that doesn’t visit much due to the distance he lives, bought his 23 cm over to me some time

The main feature of a Vector Voltmeter is that it can measure the amplitude and phase of an independent signal (one not generated by the VV itself). It can be useful for measuring embedded components.

Hi Could part of your problem(s) be that you are using the Si5351A beyond its maximum usable fundamental frequency (MUFF) where the PLL doesn't lock? I mean I haven't seen any Si5351A that would lock

Maybe phase noise limited? IIRC, i measured -70dBc/Hz at 5KHz offset for a 900MHz carrier. 6dB lower at 10kHz.