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My answer above means, as you probably know, that you can fine tune the frequency of a crystal by changing capacitors around it.

Jim KC2DHU - Let us know if you got it working. Curious to know what the results are. Thanks

--
Andrew Harmon - KD5RKO

Oh yeah, forgot the sudo step. I knew there was something else I had to do to make this work!
so:
git clone
cd nanovna-saver
sudo python3.7 -m pip install .
--
Andrew Harmon - KD5RKO

Hugen,
I noticed on the new NanoVNA-H4.2 PCB there is an unpopulated silk-screened area labeled "CARD1". Does that imply that a SanDisk card is in the works for a future version of the NanoVNA-H4? Also, with the increase in the flash size, are there any plans to eventually increase the number of measurement points?

- Herb

On Sun, Jan 12, 2020 at 01:00 PM, DaveH52 wrote:

Did you get rid of that stupid switch?
Dave

Multi-function switches still exist. In nanovna-H4, the plastic case can fully protect the multi-function switches, so it is no longer a problem. Unfortunately, our software is still not optimal, and sometimes the button requests cannot be processed normally, even if it is replaced with a button, it does not help. AA6KL is improving the software, and if the community has suggestions about the software, it can be submitted to him.

hugen

On Sat, Jan 11, 2020 at 01:45 PM, Kevin B wrote:
So I just dropped mine and the screen only turns on, nothing is displayed. Does anyone have an actual web link for a replacement?
===================================================================================

The following link was posted by another user who replaced his screen:


For exact replacement, select the touchscreen, 2.8" display. A similar unit may be available on eBay or Amazon.


- Herb

The article is a quick read:



Marco

On Sat, Jan 11, 2020 at 09:00 PM, DaveH52 wrote:

Did you get rid of that stupid switch?
======================================
Per developer and see attachment:

" - Jog switch sensitivity has been improved.
- Enter DFU (for firmware upgrade) by pressing down the jog switch at power-on. "

So no, the jog wheel switch is still present but usability is supposedly improved. Hopefully that means the switch is now interrupt driven. Looking for some of the first nanoVNA-H4 buyers to post feedback on this subject. I personally haven't experienced any switch related mechanical problems with the nanoVNA-H's that I purchased directly from hugen's Alibaba store (10 for classroom use). I can't comment on the quality of jog switches sourced by other clone manufacturers.

Gabriel Tenna White has said that her coming 3 GHz version of the nanoVNA will use push buttons instead of a multi-function switch. If the multifunction switch really irks you then that will be your best out of the box option.

- Herb

Did you get rid of that stupid switch?
Dave

I ran into this error ("python setup.py egg_info" failed with error code 1 in /tmp/pip-build....) also in Kubuntu 18.04. All known dependencies were met and the previous version had installed and ran as expected. The issue seems to be the installer was trying to write to /tmp as an ordinary user, which is not allowed. ~/tmp would have been a better choice, perhaps.

So I ran the install as sudo. It installed and seems to run OK in userspace, although I have not connected my NVNA to it yet. Whatever can of worms I may have opened by doing this I am sure I will find out later....

73

-Jim
NU0C

On Sat, 11 Jan 2020 18:46:07 -0800
post.marcel@... wrote:

Hi Jim,

I had a similar issue on Debian 10 the other day. It seems like components of the Python environment are not automatically kept up to date when simply running apt-get. So after running:

python3.7 -m pip install -U setuptools

... I also ran:

pip3 install --upgrade setuptools wheel pip3

Which then prepared the environment so I could run the nanovna-saver installer.

HTH

Marcel VK2CEL

Hi Jim,

I had a similar issue on Debian 10 the other day. It seems like components of the Python environment are not automatically kept up to date when simply running apt-get. So after running:

python3.7 -m pip install -U setuptools

... I also ran:

pip3 install --upgrade setuptools wheel pip3

Which then prepared the environment so I could run the nanovna-saver installer.

HTH

Marcel VK2CEL

225 MHz output can be achieved by operating the PLL at 900 MHz with a divider of four; that's within the spec for the PLL's VCO but the chip is not guaranteed to meet all its specifications at that frequency. Power consumption may rise and it may not other specs such as output jitter. All chips seem to have have no trouble reaching that.

300 MHz output is done by operating the PLL at higher frequencies that are out of spec: 1200 MHz for 300 MHz output. Most chips seem to at least be able to get close; exactly how close you get depends on how well you did in the silicon lottery, the operating temperature, and the operating voltage you use. Higher voltage will usually allow higher frequencies, just as it does with CPUs and RAM in computers. The NanoVNA powers the Si5351A with a 3.3V LDO, but better results might be achieved by getting its power from a 5V regulator and diode drops as is done in the QCX, which results in a higher operating voltage near 3.6V.

The input frequency might also make some difference in high frequency performance, though I haven't seen any data on what effect might have. The Adafruit and Etherkit breakout boards use a 25 MHz crystal; the Etherkit board has a TCXO option. QRP Labs products (breakout board and QCX) use a 27 MHz crystal. The NanoVNA splits the difference with a 26 MHz clock.

Operation of the NanoVNA above 300 MHz uses harmonics of the Si5351A output. As the output of the Si5351A is nominally a square wave, the odd harmonics are the strongest. I say "nominally" because it's a switching circuit, but the actual output waveform is affected by the non-zero switching time of the MOSFETS and the output capacitance of the circuit. It doesn't look all that much like a square wave when you approach the upper limits of the Si5351.

Is there a crystal somewhere? What are its tuning capacitors? And what is its load capacitance? Any room for a trimmer?

No version of the Si5351 is specified to operate about 200 MHz. The
original Si5351A, B, and C were specified to 160 MHz. The later revision,
the Si5351A-B (or B-B or C-B) are specified to work up to 200 MHz, and that
is the one you will find in just about any product you buy today. (The B
suffix parts also reduce the minimum output frequency from 8 KHz to 2.5
KHz.) Popular breakout boards like the one from Adafruit still specify an
upper limit of 160 MHz, but current production contains the Si5351A-B with
its 200 MHz spec and the boards will work up to and beyond that frequency.

Nearly all ham experimentation with the Si5351 uses the A variant. That is
the least expensive version: it comes in a 10 pin MSOP package and offers
three outputs. When the upgraded B-suffix version was released, an
Si5351A-B-GM in a 20 lead QFN package was added that offers 8 outputs but
no additional features. The Si5351B and Si5351C come in a 20 pin QFN
package; they offer eight outputs and additional clocking features. (The
first generation was also offered in a 24 pin QSOP but that was
discontinued.) Versions with pre-programmed output frequencies are also
available; they will have part numbers with additional numbers following
the B suffix.

For ham projects, the specific chip you want is the Si5351A-B-GT or
Si5351A-B-GTR. The only difference is the packaging; the GT comes in a
tube, the GTR comes in tape and reel. If you're buying for prototyping, you
will get either chips poured in an antistatic bag or a cut tape. Buy
whichever your favorite distributor has in stock or the one in the
packaging you prefer; they are usually the same price.

Hams have found that the chips can be pushed up to frequencies well above
their specifications. Other specs, like power consumption, harmonic
distortion, and phase noise are not guaranteed if the chip is operated
above 200 MHz. The NanoVNA counts on being able to run it at higher
frequencies to achieve fundamental mode operation up to 300 MHz. In the
other direction, the QCX transceiver relies on operating one of the primary
PLLs well below its specified lower limit of 600 MHz to make it possible to
generate quadrature outputs on the 80 meter band.

Unlike the Si570, a popular oscillator in other ham designs that is sold in
multiple frequency grades (with the lower grades having limits that are
programmed into the chip), the Si5351A is not locked in any way by the
manufacturer. Users are free to push the chip all the way to its inherent
limits.

Before you pass this by, thinking an idiot out in ham land can't calibrate a NanoVNA OPEN,SHORT,LOAD, THRU..... I'm not speaking of that calibration, which i found excellent in a paper "“Factory” Calibration Considerations and Procedures for the NanoVNA" That document is an expansion of Message# 233 from this groups.io website. Mostly the work of Alan Victor, W4AMV and his colleague Gary O’Neil, N3GO. That re-write and the additional material is the work of Larry Goga, AE5CZ. Kudo's

Instead - What I'm talking about is above my paygrade as I know the calibration I want is not covered. Playing with my NanoVNA; I set up a CW signal (from the touch pad) of 10.000Mhz and compared it against WWV on my ICOM 756proII using FLdigi waterfall to measure my NanoVNA frequency. My NanoVNA 110 cycles high at 10.000.00 against WWV. At least on my frequency counter I have a trimmer to zerobeat WWV.

I did a search of SI5351 and tried to figure there must be some sort of "master adjust" register as I'm thinking any ham could and should be able to bring the master frequency to within a few cycles. Especially when working with harmonics. It is described here:



I have done the "warble" in the discription where you can count 4 cycles per second adjusting my freq. counter... The paper was written by Jim N?TKN.

It's above my paygrade to develop this calibration into the NanoVNA. Any thrill seekers want to step up to the plate? Perhaps some sort of Stand alone "SI5351 master flash".program that tweaks the SI5351 and writes it through the USB cable..apparently the SI5351 can save the tweak value.

Advise.

Larry W8LM

I eventually gave up on replacing the screen on mine.

Not because I lack the skills to do it, but because I couldn't get one sent that didn't arrive smashed to bits when it arrived due to poor packing.

If/when you do order one, make it abundantly clear to the seller it must be packed properly for shipment.

--
Terry VK5TM

Thank you.
Is S11 or CH0 impedance also available in polar plot form.
Is the offset delay also saved with calibration file.
I attached a Smith chart file with a -1690 delay, does it look good. It is from a 36mm length of Teflon coax with open on other end. The delay seems long at least.

Right, W5DXP,

for lossless transmission lines and tuners the maximum power transfer theorem holds and
the location of the tuner would not matter.

But your question becomes a very important one, if lossy non 50 Ohm feed lines are involved,
where bad SWR matters much.


I just had started to study that issue by comparison: I have done two 3.51 MHz Double Zepp SimSmith
simulations, one with a single rig side tuner, the other one with two tuners. (In order to not clutter
results with tuner losses, I assumed ideal tuners.) These two simulations nicely illustrate your question.

I do hope you have SimSmith.

You can see, that by far the single best tuner plane is, where without a tuner the mismatch would be largest.
That in this case (as almost always) is at the antenna.

The results are convincing: Though you have a nice SWR = 1:1 at the TX end, the rig side tuner matched system
lets very little RF power get across the antenna feedpoint. Most power is lost in the lossy, high SWR feedline.

If the mismatch at the antenna feedpoint side is tuned away, too, we almost can transfer all of our available
power into that otherwise same antenna with same feedline.

The comparison shows:

In the two tuner system the question (a) or (b) doesn't matter, as SWR is low and thus (a) and (b) are similar.
At both places we tune to a real only generator side impedance. (b) makes no difference, as Z1 = Z1*.
But in the rig side only tuner system, the feedpoint mismatch is extreme and causes really bad losses.

Here is your point: The tuning location can matter very much. Seen that way, the Gamma or SWR at the feedpoint is
of high importance here. This is, why we imho do need (b). As SimSmith originally doesn't have (b), I calculated
it using plots. Not a problem, it just takes an extra calculation.

I think, much can be learned from this simulation. I still have some doubts concerning the powers shown in SimSmith,
as these are not consistent with what must be expected from the SWR 12.8959 as calculated by (b). At present I must leave
it still open, what causes the difference, but I dare to gueth, that (b) is correct and the 14.4 Watts at the feedpoint are not.
I will have to further study that. But I don't want to jump to conclusions prematurely. You may want to find out, too.

Excuse me for a non-finished answer. It's after midnight in Germany.

73, Hans
DJ7BA




-----Ursprüngliche Nachricht-----
Von: [email protected] <[email protected]> Im Auftrag von W5DXP
Gesendet: Samstag, 11. Januar 2020 15:05
An: [email protected]
Betreff: Re: [nanovna-users] SimSmith - great, not only for Measuring resonance from coax far end.

Hans, DJ7BA wrote: Anyone interested in more detail of (b), is invited to ask me for the derivation of (b).

Hans, because of real world losses, in a system with only one matching network, instead of a lossless system-wide conjugate match we can only have a conjugate match at a single reference plane. In most amateur systems, the matching plane is located at the Z0-match at the tuner input. My question is: Given that maximum power transfer occurs at the conjugate match reference plane, in a typical amateur radio system, where should that matching plane be located? (1) At the tuner input, (2) At the antenna feedpoint, (3) Somewhere else

Yeah it looks like a bit of a challenge but manageable. What do I look for When buying a new screen? All the screens I found have another board in them and the ribbon cable is not visible to confirm the right number of pins

Starts on Jan 25 this year and lasts for 2 weeks. Many take a one week holiday starting Jan. 24...

Roger