Keyboard Shortcuts
ctrl + shift + ? :
Show all keyboard shortcuts
ctrl + g :
Navigate to a group
ctrl + shift + f :
Find
ctrl + / :
Quick actions
esc to dismiss
Likes
- Nanovna-Users
- Messages
Search
Screened NanoVNA from eBay UK
For those who live in the UK seeking a screened NanoVNA, I have just received a black NanoVNA from eBay seller: maybeshewill (2849, 99.6% Positive Feedback). Cost ?43.50
It would appear to be correctly screened. It came with cables and a calibration pack. It appears to power-on correctly, although I haven't tested it yet. Took a while to arrive. Appreciate it is nowhere near the least expensive unit available. Also, appreciate that some feel that the screening doesn't matter. Best regards, Andrew, G1RVD |
Offtopic: nanoSA
Would it be wonderful if there would be, next to the nanoVNA, a nanoSA or nano Spectrum Analyzer?
Well I decided to test what the most simple SA could look like, just good enough to test the harmonics level of your signals till 400MHz and some other, not too complex, measurements. According to my estimate the BOM of the nanoSA on the photo would be around 12$ Main components are two SI4432 modules, one in RX mode at 443MHz using the RSSI as log detector, one as +20dBm LO for the mixer (443MHz - 886MHz), a 443mHz SAW filter as first IF filter, a Double balanced diode mixer and an arduino zero (3.3 volt) or compatible (arduino micro with 3.3v serial to USB module will also work), adding a LCD will still keep the cost below 25$ or 50$ retail. The measurement performance is surprisingly useful. Attached a scan of the harmonics and spurs of a SI5351 at 25MHz And a scan of the AD9851 ast 25MHz, both connected through a 30dB attenuator Specs: Range 0-400MHz (0-200MHz with unmodified modules) RBW selectable between 3kHz and 600kHz With RWB=300kHz noise floor below -90dBm Max signal around -5dBm Did not yet do the IIP3 measurement but the used ADE-25MH is supposed to be +13dBm Good enough for many measurements. Things to further improve: - 400MHz low pass filter at input - remove output filter of TX module to get full 400MHz bandwidth - Put everything in a box. I hope someone gets inspired and puts everything on a PCB with a LCD as a small standalone SA (nanoSA) |
Locked
Re: Inflation of this forum
I agree. This is a mess and hard to follow. It should have been a forum from the beginning. Suggest that since this project and others like it will continue into the future, that a forum should be started and all messages (if possible) be moved there. Do this ASAP.
This is my opinion. |
Re: Inductor S21 measurement using nanoVNA
Something that I have never fully understood is that S21 is supposed to beMany VNA receiver ports do NOT precisely match 50 Ohms; inserting a precision attenuator before CH1 improves matching. Isn't the "matched load" of a VNA equal to 50 ohms?nanoVNA bridge and ICs are nominally designed for 50 Ohms; I don't find a nanoVNA specification for CH1 return. Are we to assume that 50 ohms is the only possible "matched load"?Software can "calibrate" for other loads, but e.g. S11 sensitivity is not improved. For two-port measurements without precision attenuator at CH1, nanoVNA firmware does NOT compensate S11 for CH1 mismatch (see attached). Consequently, S11 measurement for 2-port DUT is ideally terminated by precision load or equivalent, rather than CH1, and use only S21 measurements for DUT terminated by CH1 while appreciating that S21 are somewhat impacted by CH1 mismatch. Warren Allgyer's 1-3000 MHz RF bridge method compensates CH1 return.. /g/nanovna-users/message/2484 |
Re: Are there any firmware releases supporting calibration kits?
On Mon, Oct 7, 2019 at 05:36 PM, Dr. David Kirkby from Kirkby Microwave Ltd wrote:
Did you mean that user will be able to enter offset delay for open, short and load and specify C0 for the open? I can try to add it at least for C0. Regarding to the delay offset, I'm not sure on how to apply it to the calibration terms. Is it correct to apply electronic delay before error term calculations? |
Locked
Re: Inflation of this forum
Hi Dave
Re hashtags: You can use whichever you prefer, i.e. email client program or web interface. A post can have more than one hashtag. Subscribers can mute a a certain hashtag if they prefer, e.g. because it is irrelevant. Bo |
Locked
Re: Inflation of this forum
Dr. David Kirkby from Kirkby Microwave Ltd
On Tue, 8 Oct 2019 at 10:08, Bo, OZ2M <groups.io@...> wrote:
Hi Does that mean that users would need to use the groups.io website, and be unable to post from an email client? If so, I would stop posting anything. I fully agree that the traffic is too high. I wrote last month that this group had more posts than any other I would have to start muting topics. The Keysight VNA forums are nowhere near as active as this one, but they have five subgroups * General Use * Applications * Programming and remote control * Calibration and Error Correction. * Handheld Instruments Obviously such subgroups would not be appropriate here - in particular ¡°Handheld Instruments¡±. *I have no experience of groups.io <> subgroups*, but if subgroups were a suitable way forward, I would suggest the following, based on my experience of the Keysight VNA group and here. *1) Beginners* I suggest this because I believe any new owners, especially if they have never used a VNA before, who are going to get overwhelmed by discussion of firmware changes, NanoVNA-Saver, the mathematics of measurement uncertainties etc. *2) Firmware development* *3 Programming and remote control* - for software like NanoVNA-Sharp, *4) Advanced applications* *& technical discussion * *5) Calibration and error correction* *6) General Use*. Dave -- Dr. David Kirkby, Kirkby Microwave Ltd, drkirkby@... Telephone 01621-680100./ +44 1621 680100 Registered in England & Wales, company number 08914892. Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United Kingdom |
Re: NanoVNA parallel R measurement
thanks, this is all helpful. I found through a few different evaluations of the info I was getting, a range of R, that got me in the ballpark and made tuning the circuit fairly painless (if anyone considers desoldering and resoldering 0603 smt's painless). I'm hoping to measure the total Q of the network and antenna now, using the nano, is this basically done setting logmag display on channel 1, hooking up the matched network and antenna to channel 1, and putting a small coil on channel 2, putting them in proximity and measuring the falloff rate of channel 1 from the maximum amplitude?
|
NanoVNA-Saver 0.1.1
I just released 0.1.1:
This version adds a first version of an analysis mode, which will analyse low-pass, high-pass and band-pass filters for you. Give it a go, and tell me how it fails ;-) Also added is easy sweeping of bands (selectable within Sweep settings), unwrapping of the phase chart, floating point min/max values for data for charts, and deleting of calibration standard sets. The release also includes a display option allowing you to select whether Return Loss should be presented as a positive or negative value. This version should behave better with multi-segment sweeps using NanoVNA firmware 0.2.2. It's slower, though. I suggest users upgrade to 0.2.3, and the next version of NanoVNA-Saver will start using the "scan" command added in edy555's firmware to get around these issues. This version should work with NanoVNA-F, though I have had no way to test it - I look forward to hearing if it does. I thank the testers who have been quick, found several bugs that I have managed to fix, and who have come up with a whole list of items that got added to the backlog! As ever, I look forward to hearing your feedback! Please be gentle ;-) Enjoy, -- Rune / 5Q5R |
broadbanding my W3DZZ on 80m
Hi,
this is not really new, but very helpful for 80m DX: I had a W3DZZ that had a sharp response in the center of the (EU) 80m Band. But CW or SSB DX is at the band ends. Before (blue curve) the W3 was only doing a reasonabl job near resonance at center. Thanks to SimSmith freeware I could determine the optimum coax length and use an appropriate L and C to flatten the frequency response. See both, before (measured with my Rigexpert AA-600) and after (measuered with NanoVNA) frequency sweep responses as displayed by NanoVNA-saver's: (I wish, NanoVNA saver could show SWR circles, too.) For more info on broadbanding (including the Smith Chart basics) see this excellent Link: enjoy, 73, Hans DJ7BA -- Diese E-Mail wurde von Avast Antivirus-Software auf Viren gepr¨¹ft. |
Locked
Re: Inflation of this forum
Hi
I all for using hashtags. A group on groups.io can be set to require hashtags and also that only the owner and moderators can create hashtags. The latter might be a good idea too. /g/nanovna-users/settings | Message Policies | Hashtags Required and Hashtag Permissions (only visible to owner) Unlike accounts on e.g. Yahoo! Groups, an account on groups.io can have a group specific profile: /g/nanovna-users/editprofile and also two different group specific standard signatures (web posting and email posting): /g/nanovna-users/editsub Thus no need to have same group profile on your NanoVNA account and your local Swinger Club. Bo |
Locked
Re: Inflation of this forum
That's why I configure 'no-email'. Now I am using web browser only.
But... I can not BLOCK anymore self promoting 9+ line signature salesman. sigh... |
Locked
Re: Inflation of this forum
When there's too much traffic from a group I switch to a daily digest. I then only read the messages from the groups.io website. Although I may miss something useful I don't have to wade through unwanted traffic in my email inbox.
-- 73 Richard G4TGJ |
Unwanted duplicate e-mails (was: Re: [nanovna-users] info update)
From: Roy Appleton
So that's what's going on. From the email readers point of view it's a mess! Roy WA0YMH ======================================== 100% agreed, Roy! An unnecessary duplication, and a proliferation of e-mails. Dave: there is a group setting which disables users from editing their messages and would prevent these unwanted multiple e-mails. 73, David GM8ARV -- SatSignal Software - Quality software for you Web: Email: david-taylor@... Twitter: @gm8arv |
Re: Inductor S21 measurement using nanoVNA
Thank you John for answering/addressing my question. Tried an air cored inductor, and the S21 attenuation was increasing almost linearly with frequency 1-300 MHz. So, as you said the the ferrite core is the reason behind this flat loss response.
I guess this means that I can use this inductor around FT23-43 effectively as an RF choke near Vcc with a bypass cap to ground for this frequency range which was the reason behind this test. |
Re: Another push button mod
Looks like it to me! Just double the price but you can get them in 3 days
toggle quoted message
Show quoted text
not 3 or 4 weeks! ? Roy WA0YMH On Mon, Oct 7, 2019, 8:19 PM David Colburn <dcolburn@...> wrote:
Is this the same switch assortment? |
to navigate to use esc to dismiss