开云体育

On Tue, Oct 1, 2019 at 08:17 AM, W5DXP wrote:

edy555_bugfix

Stupid question of the day : Where is this located ?

Tried the Files folder.
Tried
Tried

Maybe it would be good to have a sticky message that lists all the many places that firmware is available ?

73,
Steve, N2IC

Hi Dom -

I get odd 2 billion results in the 4 traces though every now

Many nanoDMA ship with firmware for only 2 traces

Rune,

I am taking a deeper look at your TDR plot. Thanks for implementing this.

I think you are plotting all of the samples of the IFFT of the S11 data. If so, I would recommend that you chop off the last half of the plot. With 5 segments (505 total samples) from 50kHz to 900 MHz I am seeing the right side of the plot indicating 55.4 m as the longest distance one could measure. I set the the cable type to RG58/U with a velocity factor of 0.66. I think 55.4 m is too large by a factor of 2. The last half of the bins in the IFFT are time delays that we won't measure in this way with real cables. As it is, you give the impression to someone that they could measure a 55.4 m cable for the settings indicated above which is not correct.

Are you applying a frequency domain window function to the data prior to doing the IFFT? If so, it would be useful to let folks know what window you are applying when it comes time for documentation. If not, there are an infinite number of possible windows. I would suggest something fairly easy to implement such as a Hanning window or a Hamming window. For cable length measurement, what you have is great.

I am interested in using the TDR to look for impedance deviations along the transmission line which can get easily obscured by time-domain sidelobes if no window is applied. I am using the TDR capability to look for coax damage or breaks in the protective jacket caused by gardening. My coax cables run through a garden area to my antennas which are above the garden. Outright breaks in the coax are fairly easy to find; however, some types of damage are a bit more difficult to observe. The TDR is especially helpful for this application.

I do like the separate plotting capability you have implemented for the TDR data which is in the same window as the coax definition. I have noticed that once you put it into the main window as one of the graphs, you cannot ever see the TDR data again as a separate plot unless you restart the program. It seems like it would be a good idea to restore the plot to the TDR window if it is removed from the plots in the main window or just permanently leave it in the separate window that the user can bring up as desired?

Another alternative is to only plot the TDR data in the main window. When the TDR plot is a graph in the main window you should show at least the velocity factor you have assumed on the TDR plot and perhaps the cable type the user selected. This makes the plot self-contained when it is saved as an image. I prefer a separate window where I can make the TDR plot as big as my screen; however, that is not in any way essential and probably makes more work for you.

Thanks, again, for your great work on this software. I greatly appreciate it.

73,
Bryan, WA5VAH

If you have alternative suggestions for ready made cheap test boards I am sure
many would love to hear about them?

FWIW, I got this $6 SMA attenuation breadboard


Dremel open the 0dB line and attach UHF DUT of interest.

On Thu, 3 Oct 2019 at 15:15, Dom Baines M1KTA via Groups.Io <dombaines=
[email protected]> wrote:

On Thu, Oct 3, 2019 at 02:44 PM, Dr. David Kirkby from Kirkby Microwave
Ltd wrote:

SDR-KITS

You mean this one?


The suggestion of the ebay board stimulated discussion which is a good
thing as I suspect some will have a need to see could this test 'whatever'
and if it does what does the output look like?
I would have thought either might be a step up from a veroboard or a bit
of FR4 (or better) with an SMA on either end and some test circuit or mount
in between.

I am sure many of us have created such PCB with bnc/sma etc at either end
you put/mount/wire some test rig or item in between.
Might be a guess but expect lpf/bpf, xta filters, RC/LC networks and a
number of devices have been tested in this manner before (not with the
nanovna of course)

If you have alternative suggestions for ready made cheap test boards I am
sure many would love to hear about them?

72

Dom
M1KTA

Yes. Note that there’s a basic board and are more advanced one. Both are
under ?20. I think that they are designed to be *educational*.

I am not saying that the Chinese board is totally useless, but for a PCB
with connectors that have quite a limited lifetime, and a small number of
cheap components, it seems quite expensive to me.

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

My order show shipped today. Now the waiting begins.

Really just a larger font with only 2 traces available - do not install yet - they are buggy.

DO NOT INSTALL the AA versions of hugen's Oct-3-2019 firmware
- they are buggy and will lock-up your device right after calibrating the touchscreen!

Please wait until hugen fixes them.
The CH versions work as far as I have tested.

On Thu, Oct 3, 2019 at 02:44 PM, Dr. David Kirkby from Kirkby Microwave Ltd wrote:

SDR-KITS

You mean this one?


The suggestion of the ebay board stimulated discussion which is a good thing as I suspect some will have a need to see could this test 'whatever' and if it does what does the output look like?
I would have thought either might be a step up from a veroboard or a bit of FR4 (or better) with an SMA on either end and some test circuit or mount in between.

I am sure many of us have created such PCB with bnc/sma etc at either end you put/mount/wire some test rig or item in between.
Might be a guess but expect lpf/bpf, xta filters, RC/LC networks and a number of devices have been tested in this manner before (not with the nanovna of course)

If you have alternative suggestions for ready made cheap test boards I am sure many would love to hear about them?

72

Dom
M1KTA

Hi Mike,
way to up the ante! I'm getting nervous now! ;-)

I'll see how much of it I can figure out for the next release.

--
Rune / 5Q5R

On Thu, 3 Oct 2019 at 15:45, mike watts via Groups.Io <wy6k=
[email protected]> wrote:

Yes, all of those filter measurements would be useful for things I do.
Those functions would elevate you from "hero" to "demi-god" in my world.
:-)
Mike WY6K


"... somewhere in the distance, there's a tower and a light, broadcastin'
the resistance, through the rain and through the night..."

On Thursday, October 3, 2019, 4:20:50 AM CDT, Rune Broberg <
mihtjel@...> wrote:

Hi Norbert,
the application can run calibrations at far more than 401 points - I have
certainly done 5050 points at one point. ;-) But it does this in the
application, and not on the device, due to the hardware limitations.

I agree that a function to find cut-off frequencies for filters etc. would
be interesting, and I've put it on the list of features I would like to
implement for the next version, ie. for next week. I don't make any
promises though :-)

What measurements would be relevant to provide? Cut-off frequency, span for
band-pass, dB/octave and dB/decade fall-off, pass-band ripple?

--
Rune / 5Q5R

On Thu, 3 Oct 2019 at 11:12, <norbert.kohns@...> wrote:

Hi Rune,
thank you for fixing this issue!
I have a question for you in respect to the required number of data

points

to measure a band pass filter. With 101 points it is most likely not
possible to find the -3 dB points because the sample point is way off

from

-3 dB on both sides of the band pass. With 401 points it would work. An
automatic feature of measuring the bandwidth would be absolutely cool!

The

TAPR software is able to perform a calibration at 401 points or even more
than that, so I am certain that you could do that as well. I have no

glue

on how difficult that would be, but more data points for calibration

would

be a huge improvement.

Kind regards
Norbert, DG1KPN

DFU file size depends on some garbage information. I buld firmware and it has about 60 kB size. When you translate it into DFU, it's size will increase and it depends on the folder name which is used to store hex file before conversion to DFU

Larry,?
Does the AA version do anything that the other version does not?? Or is it just the readability?
Mike WY6K


"... somewhere in the distance, there's a tower and a light, broadcastin' the resistance, through the rain and through the night..."

Yes, all of those filter measurements would be useful for things I do.? Those functions would elevate you from "hero" to "demi-god" in my world.? :-)
Mike WY6K


"... somewhere in the distance, there's a tower and a light, broadcastin' the resistance, through the rain and through the night..."

On Thu, 3 Oct 2019 at 09:53, Gerry Kavanagh via Groups.Io <gerrykav=
[email protected]> wrote:

Nice idea. I wonder how long those little u.fl connectors will last though.

Hirose, the designer of the U.FL connector, says *20 matings. *

IMHO, it would be cheaper and better to just get some chassis mount SMA
connectors and assemble something oneself. eBay item 183574973423 has 5 SMA
connectors at $2.80 delivered to the UK.

* Opens can be made free.
* Shorts can be made for the cost of a bit of solder.???
* Other devices can be made very cheaply.

Working out the S-parameters

If you look at the cost of that board, it is *much* more expensive than far
more sophisticated PCBs available from China. To me at least, it seems a
relatively large amount of money for something that has very little
substance to it.

SDR-KITS sell a test board that seems to offer much more room for
experimentation at a better price.

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

I believe thay are rated for fewer than 10 insertions.

Folks,

Hugen has built several up-to-date (as of Oct 3, 2019) versions of his Antenna Analyser (AA) firmware for the NanoVNA.

These have the thicker fonts that are easier to read.
The entire drive download is 20MB and contains a lot of older files, so you may want to only D/L what you need.

On the Google drive here:


bin, hex & dfu files:
NanoVNA-H__900_ch_20191003
NanoVNA-H__900_aa_20191003
NanoVNA-H__800_ch_20191003
NanoVNA-H__800_aa_20191003

Hi Rune
here you are!

73, Norbert, DG1KPN

Great answer thanks. I think though this time I'll just get the 800 file because I do not need to analyze at 900 MHz (not even 800 really).

As everyone already knows, this little unit is amazing for the price. I've already convinced several friends in the area to buy one.

Hello Norbert,
It looks good! The number of points setting is the (slightly convoluted)
"segments" setting, providing 101 points per segment. But since there's
been a lot of questions about it, maybe I will try to make it more obvious.

Could you send me the resulting S2P file for the bandpass filter? I need
some test data for making a filter analysis section ;-)

Thanks,
--
Rune / 5Q5R

Chinese fonts take up more room.

BTW - hugen has released the TWO TRACE 'AA' version of the latest firmware, located on the Google Drive below.
There are both 800MHZ and 900MHz versions.

Regards,
Larry