开云体育

Jeffrey,
I've worked slightly more on the ideas you presented, and just pushed an
update that makes it *nearly* fit on a 768 pixel screen. It does actually
fit, I believe, if you hide the task bar. I think that's as good as it's
going to get for today :-)

It should probably fit with font size 7, I think anyway. :-)

--
Rune / 5Q5R

On Thu, 19 Sep 2019 at 07:07, Jeffrey Vandenbroucke <jeffrey@...>
wrote:

CollapsibleBox(QtWidgets.QWidget) would be handy - you can "hide" controls
you don't need then.

For myself, I patched the charts to be 300px in height max. Ditched the
s11_control_box and s21_control_box (and the setText statements); as I can
read that with markers. Font size set to 7; and removed the about box. Now
it fits snug inside my (small) display.

Said,
I posted this procedure earlier that I used to check the gain of a RF preamp. The device under test was a Mini-Circuits preamp with a handwritten note saying, "27 dB gain, 1-1000 MHz".

Test procedure used:
1. Turn the amplifier on to allow it to warm up and also to guard against turn on transients damaging the nanoVNA during testing.
2. Turn on the nanoVNA, set the display to CH1/LOGMAG only, 10 dB per DIV, reference position at 4 divisions to be able to see 27 dB gain.
3. Connect a 20 dB attenuator to CH1 and a 6 dB attenuator to CH0 to closely match the expected 27 dB gain of the preamp.
4. Connect attenuators together using a cable. The nanoVNA should be displaying a 26 dB loss over the frequency range. If not your attenuators are not flat
5. Change to the calibrate menu and select "reset" and then perform a "through" calibration. The new reference should be 0 dB at 4 divisions.
6. Connect the output of the 6 dB attenuator to the input of the amplifier and output of the amplifier to the 20 dB attenuator.
7. Read the amplifier gain in dB directly off the nanoVNA using the marker display.

The above only checks the S21 performance of the preamp. That was all I was interested in at the time.

Kurt,
Thanks for the comments. I am fortunate to have a commercial BNC VSWR kit that came with OSL standards plus various mismatches. I picked it up from an engineer's estate sell and was able to verify the kit's performance up to 1 GHz using a HP8753C VNA. The kit is my gold standard against which I verified my everyday use home made BNC OSL. The home made BNC OSL (see attached photo) pretty much follow your construction suggestions, except the 50 ohm load is an HP11593A (picked up two at the same estate sell). I was told the commercial VSWR kit was manufactured by Berkeley labs but have not been able to verify that info.

Very thanks for quick answer qrp.ddc. I made the 2nd manipulation with 20db connected to ch0 & ch1 and turned the Orange & blue traces & have had the S21 & S11.I think i was wrong.
The amplifiers are 20-24db 2m band.
I made a calibration with the 2 Attenuatos connected to have a zero instead of 40db.
Very thanks for infos & 73s dr qrp.ddc

in order to measure S11, you're needs to put 50 ohm load on LNA output and connect CH0 to LNA input. But first, make sure that your LNA can handle 0 dBm level! If it cannot, then there is no simple way to measure S11. If your LNA cannot handle 0 dBm on the input, do not connect it directly to NanoVNA, because you can damage LNA input.

in order to measure S21, you're needs to connect LNA input to CH0 through 20 dB attenuator. And LNA output to CH1 through 20 dB attenuator.

It's better to use 30-40 dB attenuator between LNA output and CH1. But 20 dB also may work if your LNA has not so high gain (smaller than 30 dB).

For high gain LNA (more than 30 dB) you will need 40 dB attenuator between LNA output and CH1, otherwise your CH1 input on NanoVNA may burn out. Do not connect high gain LNA output directly to NanoVNA, you can damage NanoVNA!

You're needs to add attenuators sum to the measured S21 values. In your case you will need to add 40 dB to measured S21. For example, if it shows S21=-30 dB, it means that LNA gain is -30+40=+10 dB.

hwalker, you can find adapter delay by connect unmatched terminator and check Group Delay screen. Of course it will also include delay of terminator, but with a series of measurement you can find exact delay for adapter and for terminator.

Thanks Rune,
That makes life much easier.

David

--
David G Hopkins (VK4ZF)


---
This email has been checked for viruses by AVG.

My $300 laptop has 1920 x 1080.
Great for video etc but awful for running normal software on, what a crazy situation.
The result is everything looks so tiny on the menus on 90% of the programs in use.
I often have to go into the desktop settings and tell my machine to use a lower resolution :-(

I think the manufacturers are forgetting that PC's are work tools, and are NOT ll about
games and movies !

73 de Andy
======================================

I think that a great majority of the devices sold today (at least the lower-cost ones) have 1920 x 1080 displays, so it's a sensible standard for which to design. I still have some 1280 x 1024, one 1280 x 768, and two 1600 x 1200 (I prefer the greater number of lines for programming and spreadsheets).

My Linx tablet with its 1920 x 1080 x 250 mm display is "challenging" to read, but does run some SDR software well.

(Next challenge is 4/5K displays...)

73,
David GM8ARV
--
SatSignal Software - Quality software for you
Web:
Email: david-taylor@...
Twitter: @gm8arv

I have the same issue. But use another USB cable is sometimes better. If i push OK in the serialPort window, the port is recognized after a few attempts. But yes,it is not ideal.

The IP5303 chip turns on when the load is connected.
Connect a 20-100 ohm resistor to terminal 8 and the GND, if switching on does not occur, replace IP5303.

Hi hwalker
One comment to you BNC calibration test. Are you cal kit home made with three bulhead adaptors where 2x100 ohm SMD fitted to the centerpin as load and the open as well the load has the center filed down flush with the rear of the adaptors and the short is with a copper or brass disk soldered to the rear then you are "calibrating to the rear" and not to the BNC reference plane then you pretty well calibrated as such a kit is sort of ideal. However if another sort of kit you are trouble by delays in open and short and load may be quit reactive inductive or capacitive you do not encounter for.
The NanoVNA-saver has facilities for entering such delays of short and open.
Kind regards
Kurt

-----Oprindelig meddelelse-----
Fra: [email protected] <[email protected]> P? vegne af hwalker
Sendt: 19. september 2019 00:47
Til: [email protected]
Emne: [nanovna-users] Electrical Delay_Port Extension

Most of the RF equipment I own have BNC connectors, so one of the first things I did was install SMA-BNC adapters on channels 0 and 1 of my nanoVNA. After recalibrating using a 50 ohm BNC OSL kit, the Smith chart display looked as expected when BNC OSL standards were sequentially connected to CH0. BNC mismatches of 33, 75, 100 and 150 ohms all looked good with expected return losses. I saved the BNC calibration data in "SAVE 1" and retained the original SMA calibration in "SAVE 0" in case I need to remove the SMA-BNC adapters.

qrp.ddc's discussion in group regarding the electrical delay menu option reminded me of how the port extension feature of the HP8753C was used to correct for an adapter attached to the native "N" connector. The HP8753C has a menu option allowing you to enter an electrical delay value, extending the measurement plane out to the end of the adapter and correcting for its additional length. I wondered if this would work with the nanoVNA and so tried the following:

1.Turn on nanoVNA. With nothing connected to the CH0 BNC adapter, the Smith chart displays an open with a tail corresponding to the reactance of the SMA-BNC adapter.

2. On the nanoVNA select DISPLAY_SCALE_ELECTRICAL DELAY.

3. I didn't have a clue as to the electrical delay value for the SMA-BNC adapter, so starting at 100 (ps?) I tried successive values until the nanoVNA displayed a single dot with no tail to the far right of the Smith Chart display. The value needed to achieve this for my SMA-BNC adapter was 180 x 1 as entered on the nanovna screen keypad.

4. With BNC OSL standards sequentially connected to CH0, the results looked almost as good as the original SMA calibration data.

5. BNC mismatches of 33, 75, 100 and 150 ohms looked as good or better than the values obtained during the earlier calibration using my BNC OSL kit.

6. I saved the port extension corrected data in "SAVE 2" .


Thanks qrp.ddc for pointing out the electrical delay menu option and how it could be used for correcting for port extensions. For those users that want to add different adapters to channels 0 and 1 but don't have a suitable OSL kit to correct for the adapters, give the electrical delay menu option a try.

Hi. I just bought the NanoVNA and want to make some tests on some LNAs.I have 2 SMA 20db Attenuators.How to setup the VNA & how S11 is important in the Tuning.Very thanks for answers.Regards Sid.

Edit:
A warning. I was inspired to use another USB-C cable. Very strange is that with the supplied USB (black) cable the NanoVNA won't start connected to the PC.
I did a test with a self-purchased (white) USB-C cable, and guess what: the NanoVNA will now start up if it is connected to the PC when I press the PWR switch.
So be careful with the supplied USB cable.

With all that new firmware, I now work a lot with the NanoVNA connected to the PC. With my modification in message # 967 I can start the NanoVNA with the placed switch on the IP5303.
But once connected via USB to the PC, that is no longer possible. As soon as the USB is connected to the PC, I can no longer start up, and the circuit of the IP5303 no longer works.
When disconnecting the USB and reconnecting, the NanoVNA will start up, but then the running PC program will be interrupted. Someone a solution?

Hi Andy,

Hi, Andy,

but your call also seemed familiar to me ;o)
Yes, it's true, on 17.07.2017, in the morning at 04:30 I had a direct hit in my LF antenna. The antenna was disconnected but unfortunately not grounded. Because of this the flash could jump over to the VHF/UHF mast, 6m away. So it was in the shack and left a smoking ruin :o((
I found parts of the 4m transverter 15m away, around the corner, which must have flown like projectiles through the shack. All 3 main fuses (63A) it "atomized". All electronics in the house were destroyed, even sockets were blown out of the wall. I could repair a lot since then but a lot is lost.
In the meantime I have also changed the QTH and only very limited antenna possibilities. But this will change in spring, when we move to a farm at the Dutch border, with a lot of space.
Then the grabbers will go online again. At the moment I'm experimenting with a frame antenna on LF/MF incl. transmission attempts, but so far nobody has heard me in WSPR. The power from the Ultimate 3 is too low, but I'm working on a small 400 W PA, with 50 - 70 W in the frame I should be heard then, hopefully ;o)))
Information about the frame experiments can be found here:

73 Joe

Hi Hugen,
this sounds very good! Are you looking at expanding the
frequency/measurement range by a change of components as well?

I'm happy to hear that you will stay consistent with the NanoVNA, but any
necessary improvements to the commands will, of course, be quickly
implemented by the application developers. :-)

--
Rune / 5Q5R

Using the cho45’s web interface can use nanoVNA very good on the phone , I think this is a very good expansion screen scheme. I'm also trying a 3.5-inch LCD, maybe working with the STM32F303 to create a new NanoVNA, and I want to be as consistent as possible with the NanoVNA for better community support. NanoVNA-F is a very good project to use a larger LCD, but it uses the expensive MDK compiler.

Thank You！

hugen

This is the latest version of the edy555 that includes the TDR feature. I have modified the touchscreen calibration value before compiling and can be used directly with the 2.8-inch NanoVNA.

Done

Maybe it would fit better in the Firmware section? ;-)

Good work!

--
Rune / 5Q5R