开云体育

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

Rune has released a "Back From Christmas Update" a few hours ago. See details at: . I'll leave it to Rune to go into any particulars.

- Herb

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 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?
===========================================

Kevin,
Replacing the screen is a pretty delicate de-soldering and re-soldering operation. Totally doable if you have good soldering skills. If not, you might consider putting the money for a new screens towards purchasing the new 4" screen version of the NanoVNA-H4. The LCD for the NanoVNA-H4 is not soldered to the pcb (see attachment) so if you have an "Oops, I did it again" moment, screen replacement should be easier.

Sorry about your screen and not answering your original link request.

- Herb

Hi Dave,

Yes, you are right: There are good examples when we don't want or need perfect conjugate match by
design (or whatever other) reasons.

No matter, if we need it, can use it, or want it or not, (b) still generally describes physics of power
transfer, while (a) doesn't - except for the quite common special case: No generator reactance.
In this special case the general formula (a) flaw (wrong reactance compensation) is zero, as Z1 = Z1*.
In an almost tuned situation, the fault is marginal only and in practice often hardly matters. So the (a)
or (b) question often is no big issue. For electrically short antennas it may, however, be significant.

We are talking about a connection of two impedances, be they made of lumped serial elements, or be
they the Thévenin impedance at some point (=equivalent impedance toward the generator), connected
to the load impedance (=equivalent impedance toward the load).

And we are talking about physically correct power transfer description, which mostly is what we want,
unless the aim is echo suppression, maybe for an old time analog TV ghost suppression, stealth radar
applications, or whistle suppression on long phone lines. In these cases the reflection suppressionn is
most important, and there we correctly must use (a) instead of (b).

Reflection at a line termination, correctly described by (a), is not the same physical phenomenon as the
role of impedances in a serial circuit, that only is generally correctly described by (b). (Any parallel circuit
could be recalculated to be a serial equivalent, so "serial" will do.)

Contrary to echo suppression, however, most DXers want to get through in a pileup. Maximum possible
signal received by the rare DX station is achieved by max. real power transferred to our transmitting antenna.
I never heard of echo suppression in that context.


Thanks, Dave for suggesting your nice application of a modern very low internal resistance PA.

These units have a limit: That usually is max. PA heat dissipation. That's why the specs allow a certain max. SWR,
or else the TX protection circuit will reduce RF power or even switch off. In most 1.8 ... 30 MHz low internal resistance
PAs we have filters for different frequency ranges. These are necessary to suppress possible oscillations at certain
frequencies. Because of these filters we don't have a purely resistive internal impedance at the antenna socket.


A look at the PA specs:

Let's arbitrarily assume your modern PA has an internal generator impedance of 8 +j 2 Ohms at a frequency of interest.
Let's further assume, the PA's max. permitted SWR is 2.0 with 50 + j 0 Ohms reference.

This indeed means, we cannot make full use of perfect conjugate match anyway, be it using (a) or (b). For some,
the discussion here ends. That's ok. But let's have a closer look:

If we had no reactive parts in the generator, max power could be sent to the antenna, if the load was 25 + j 0 Ohms:
But we have a reactive part of + j2 Ohms, that (b) will compensate, while (a) would not compensate, but double it.

Resulting from (a) is a blind current that does not increase the radiated real power, only unnecessarily increases the current
through the generator's 8 Ohm resistive part, causing more heat in it and sooner action of the protection circuit, triggered
by the somewhat worse SWR due to the (doubled) reactive component.

On the bottom line:

I cannot see why your modern PA application could causes (a) to be any better than (b) - as both are limited by other reasons.
(a) is even limited a bit earlier.

Nothing speaks against (b) when trying to generally make best power match in so many applications.

Having said this: SimSmith (though not in the manual, but elsewhere: W0QE, who made many videos on SimSmith) sais:

You should us Z1* instead of Z1.
That is only correct for perfect match. Otherwise it would
result in:

Gamma = (Z1 - Z1*) / (Z2 + Z1*) (c).
But sorry: That also does not generally compensate the reactive parts either, except at perfect conjugate match. Only (b) does.

So (c) also does not correctly describe power transfer for poorly matched situations, that in practice easily do occur, as antenna
heights and resonance as well as ground conditions often cannot be changed to what would be the perfect ideal 50 + j0 Ohm
feedpoint impedance.


But - in spite of all above: I cannot stress it often enough:

I have not seen any better free software for the earnest radio amateur than SimSmith.
The missing of (b) can never be a good enough reason to not use SimSmith.

Go, get it, if you havn't yet.

If you know (b), you can calculate with it in SimSmith. Just use the plots feature. It accepts complex math formula.

So the value of mentioning (b), though the theory is correct, imho is worth not much more than a necessary footnote.
Many only know (a) and it serves them, too. Though scarcely known, others use (b), but SimSmith doesn't.

73, Hans
DJ7BA

-----Ursprüngliche Nachricht-----
Von: [email protected] <[email protected]> Im Auftrag von David Eckhardt
Gesendet: Samstag, 11. Januar 2020 17:13
An: NANO VNA <[email protected]>
Betreff: Re: [nanovna-users] SimSmith - great, not only for Measuring resonance from coax far end.

Dig further back into the matching system. In our modern transceivers, the match begins at the collector / drain of the output devices (the PA).
There is typically no attempt to do conjugation at that point, just bring the impedance from the (generally) far left of the Smith Chart to something significantly closer to the center of the chart. This must be accomplished in a broadband manner.

Dave - W?LEV

--

*Dave - W?LEV*
*Just Let Darwin Work*
*Just Think*

So I just dropped mine and the screen only turns on, nothing is displayed. Does anyone have an actual web link for a replacement?

On Wed, Jan 8, 2020 at 09:46 AM, Larry Rothman wrote:

if you ever perform a full clearconfig command via the console or install new
firmware, you will need to reset the threshold level again.

Gee, it would sure be nice if some of the firmware upgrade instructions actually mentioned that you need to reset
the threshold level. :-)

Hi can some one compare the 4" Nanovna V Nanovna-F, Good and bad points, not just the cost,
Thanks Dave 2E0DMB

Those who ordered anything from China recently, be aware that it's soon the Ney Year's Holiday (rat year) so orders myy be delayed.

Cheers,
David
--
SatSignal Software - Quality software for you
Web:
Email: david-taylor@...
Twitter: @gm8arv

I ordered the 4” yesterday from Hugen’s Alibaba presence and Maggie emailed me a PayPal invoice at 8:01 Saturday morning her time. Her reply to my payment did not come back to my personal email address, but stayed inside the Alibaba messaging system.

I’m looking forward to the larger screen and other improvements :-).

It would be 4:00 am Sunday for her right now.

73
Bruce W4CG

Yes, Express.? No acknowledgement of the order yet...maybe they do not work weekends ;-)

73

Glen K4KV