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I think it just means that they are the first to get "authorized" to sell for ttrftech which seems to be associated with edy555 the original designer. I have had good experiences with nooelec and think that they are okay. For the extra money it looks like you some extra cables and attenuators. I wonder if the cal kit is better than the usual one?

Unfortunately they only ship within the continental USA but they have a really nice selection at good prices.?


On Sat, 12 Oct 2019 at 9:42 AM, Oristo<ormpoa@...> wrote: > Well at least I tried to raise the issue :-)

Folks might care more if firmware optionally supported
replacing multi-function switch by e.g. rotary encoder with pushbutton

Well at least I tried to raise the issue :-)

Folks might care more if firmware optionally supported
replacing multi-function switch by e.g. rotary encoder with pushbutton

Try to save 2 times in a row.
I use this firmware on my two devices, it is used by my friend, there are no problems. Perhaps you are not using a reset during calibration.

Well at least I tried to raise the issue :-)

So I guess it's back to the endless calibration threads.

Thanks for suggesting the 'mute' option.

Regards,

Martin - G8JNJ

Found a nice website from Jacques Audet, VE2AZX, (English and French)

added to /g/nanovna-users/wiki/External-links

On Sat, 12 Oct 2019 at 03:37, Starsekr via Groups.Io <Starsekr=
[email protected]> wrote:

David,
Could you give the group a short form on how this is done, and what a
NanoVNA user would do and see to measure something like a piece of RG6 or a
75-300 ohm transformer? Not to take away from your sales, but what kind of
error would a pad made from 1% carbon resistors introduce, compared to a
commercial pad?

I don’t sell 75 ohm kits, neither do I sell matching pads - only 50 ohm
kits and consultancy services.

I heard a report somewhere on here that the receiver port on the NanoVNA
is not particularly close to 50 ohms and varies on the batch a given device
is from. That’s something I would like to fix myself, which could be done
with a few 1% resistors, after measuring the impedance.

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

On Sat, 12 Oct 2019 at 05:53, Larry Benko <xxw0qe@...> wrote:

Dave,

Please educate me. Suppose I build a product that has a SMA-F connector
on it and you and I are going to measure S11 for my product. The only
way we are able to get the same answer is if there is an agreed upon
definition as to where within the mated SMA connectors we are going to
call the reference plane. Agreed?

The MIL standard for the SMA connector defines the reference plane.

The most accurate way to calibrate my measuring equipment is to connect

a cable to it that is terminated in an SMA-M connector and then
calibrate it with calibration O/S/L standards that have SMA-F
connectors. This eliminates any adapters being needed. Agreed?

Yes. agreed.

Since my O/S/L standards have some physical length I will need to move
the reference plane closer to the measuring equipment by some small
amount. To my way of thinking this can be done either by the measuring
equipment automatically of manually by doing some line extension.

Is this incorrect?

*No, that’s wrong.*

You should

1) Configure the 8753 to use the 85033D coefficients. From memory, that’s
something like

CAL (physical button on 8753)
Select Cal kit (soft key)
Press the soft key corresponding to the 85033D.
Return

Now just calibrate the instrument properly, then make your measurement.
There’s no need to mess around adding any delays - as Alan pointed out,
that will screw your results up

Larry, W0QE

Dave, G8WRB
--
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

Hi All

I have seen/heard someone got a Hugen NanoVNA-H clearly printed on the read and with display start-up screen also showing the NanoVNA trade mark

I believed I got an original Hugen by ordering from Alibaba.com where it was stated so and described as the Original one, but is was not branded Hugen.

Anyway try to go to A,ibaba,com and serach for NanoVNA-H and you is prompted a nice kitted version and in a case as well. The Thru Adaptor seem to be the new lossless one so I ordered one just for that ? No I am kidding.

Here is the picture for this nice kitted product

Kind regards

Kurt

Hello,

This email message is a notification to let you know that the following files have been uploaded to the Files area of the [email protected] group.

• /Vector network analyser comparisions.pdf

Uploaded By: Starsekr <Starsekr@...>

Description:
Vector Network Analyser comparisions by Rudy Severns N6LF in 2007. Has some simple tests of VNAs that were generally available to Radio Amateurs and electronic experimenters in 2007

Cheers,
The Groups.io Team

Yes Alan, in general the loaded Q is given by: 1/Q =1/Q1 + 1/Q2. Unless the matching network is of very high Q then it won't work. Furthermore you cannot have too high a Q for a matching network. For e.g. the Q of the L network is related to the impedance match ratio by Sqrt(+Q^2).

@IPA wrote:

What does the ch firmware have that the aa doesn't ?
----------------------------------------------------------------------------------------------------------------------------------------


From Oristopo's NanoVNA firmware help page ( ):


aa "Antenna Analyzer" limited to 2 traces but usefully larger text.
Use ch for 4 traces, but smaller text

- Herb

Thanks guys. I will update to the latest firmware. What does the ch firmware have that the aa doesn't ?

Found a nice website from Jacques Audet, VE2AZX, (English and French) which has some Excel spreadshhets for VNA S11 values. It seems to provide measurement corrections from 50 ohm cal to 75 ohm system measurements. Also some practical examples of impedance and antenna measurements.

On Sat, 12 Oct 2019 at 02:44, alan victor <avictor73@...> wrote:

Here is a cut and paste from the Microwave101 web site.
I hope by reference to THEM, I am observing the proper copyright method!!
Regards, Alan
=======================================
Why doesn't an open or short look like a dot on the Smith chart?

To get another view of this same topic, see



I would welcome any comments, either positive or negative.

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

Dave,

Please educate me.? Suppose I build a product that has a SMA-F connector on it and you and I are going to measure S11 for my product.? The only way we are able to get the same answer is if there is an agreed upon definition as to where within the mated SMA connectors we are going to call the reference plane.? Agreed?

The most accurate way to calibrate my measuring equipment is to connect a cable to it that is terminated in an SMA-M connector and then calibrate it with calibration O/S/L standards that have SMA-F connectors.? This eliminates any adapters being needed.? Agreed?

Since my O/S/L standards have some physical length I will need to move the reference plane closer to the measuring equipment by some small amount.? To my way of thinking this can be done either by the measuring equipment automatically of manually by doing some line extension.

Is this incorrect?

Larry, W0QE

On Sat, 12 Oct 2019 at 02:37, alan victor <avictor73@...> wrote:

Hello Larry,

I believe this issue, particularly with the 3.5 mm cal kit is presented in
a number of application briefs from HP, Keysight, R&S and Wiltron. I'll see
if I can find these references.

Alan

Alan,
I concur with that. Certainly for any kits I have, the effect is most
pronounced with the 3.5 mm kits. On the HP 85052B 3.5 mm kit, the arcs will
do a full 360 degrees around the Smith Chart by about 16 GHz. Neither my
85050B (18 GHz APC7), nor 85054B (18 GHz N) show the effected as pronounced
as the 3.5 mm kit.

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

On Sat, 12 Oct 2019 at 03:13, Larry Benko <xxw0qe@...> wrote:

Alan,

I understand what you are saying well. Since any calibration standards
will have some physical length you or the analyzer needs to subtract
this length before you can make accurate measurements.

No, neither the user nor the analyzer has to subtract any physical length.
Doing that would give reasonable results, but certainly not as accurate as
the 8753 is capable of.

In fact, with proper support in the firmware, and correct use, the NanoVNA
might outperform the 8753 in some measurements if one just subtracted a
delay on the 8753.

Just considering the open, there are 3 parameters that need to be taken
into account. In order of decreasing importance these are

1) Offset length
2) Capacitance, which is frequency dependant
3) Loss, which is frequency dependant.

The 8753

analyzer family does this length correction automatically which is why
the open and short cal. standards show as arcs. I have never seen any
small hobby type VNAs do this automatic correction.

I don’t know what you mean by “automatically”. The 8753 has no way to
automatically determine the offset length, capacitance or loss of the
standards.

The VNWA will show arcs for the calibration standards, and so will some
Deepace products. They are all aimed at the amateur market


Larry, W0QE


Dave, G8WRB

--

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

DMR
This firmware seems more responsive on the keyboard and switch, but still cannot get it to 'save' correctly; Tried loading the Clear Memory firmware first few times also the other versions of it as well. Everything else is working very well. Thanks.
Like the blue colouring ...