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Hello Vidas,

Monday, September 14, 2020

Exact same problem with one from a UK seller, rather than mess with it I sent it back. Ebay supplied a link to print the return label from, which I did and I posted it off. The seller then demanded to know what address it had gone to, of course, it had gone, so I couldn't say. You'd think the seller himself would know what address they had furnished Ebay with... I have a very short fuse with Chinese stuff and China at the moment so I will stick with my AIM4170 :) 2E0ILY


Best regards,
Chris mailto:chris@...


Nvgi> Looking at the SMS's with naked eye they appear ok. Like I
Nvgi> stated on original post, the die goes on and off with no
Nvgi> resistance at all. I can wiggle the die with all threads inside
Nvgi> of die which to me seems like the connectors diameter is a
Nvgi> little too small. Center female pin looks fine using small
Nvgi> magnifying glass, but that's just my opinion since I do not have
Nvgi> the proper tools for making measurements on SMS's.
Nvgi> THANK YOU ALL for your inputs !

Nvgi> Colin, are you getting the 6 to 8 hours of battery run time on yours?

Nvgi> Vidas

Nvgi>

The dumbing down of ham radio has been going on for a long time.

Что есть -Окорок?:)

I will venture I guess and say that most hams
do not understand SWR. Anyway most hams,
these days, are appliance operators so no surprise there.

Most of the hams in my local club only understand SWR and have never seen a Smith chart, and are not interested in learning about it. They just want to get their antenna adjusted before the big DX contest. Most hams also have no interest in anything operating above 148 MHz.

MFJ will do fine selling to this market, which is much larger than that of the hams who studied electrical engineering in college.

Dan, N8FGV

You are better off using a larger number of 101 sample 'bins'. With a cal.
from 50 kHz to 1 GHz and using only 1 "bin", you have only 101 points
across that sweep. That would amount to a measurement of the cal and data
every 9.9 MHz. The resolution with that cal applied to any 2-meter or 70
cm filter will be unacceptable. If you specify 10 bins of 101 points each,
that will yield a measurement and cal point every 0.99 MHz. Still pretty
bad resolution. It is not a trick of the display, but the number of actual
cal'ed and measured points. So, to get a meaningful display and
measurement, its better to define a much smaller sweep appropriate to what
you are after and assess the granularity of the data to set the number of
'bins' over that sweep.

The result of your comparison between the duplexer and triplexer may well
be correct. With the triplexer, you have the added roll-off contributed by
the center BPF to add to the high-frequency skirt of the 2-meter LPF and
the low-frequency skirt of the 70-cm HPF. That likely accounts for the 8
dB difference between the two designs.

Dave - W?LEV

On Mon, Sep 14, 2020 at 9:31 AM Hasan Schiers N0AN <
hbasri.schiers6@...> wrote:

I have a nanoVNA-F that I am very pleased with.
I have done the internal calibration.

I use nanosaver software on Win10, and am also very pleased with it. Do I
recalibrate using the nanosaver software for every different band filter I
am testing and save that calibration using the nanosaver software?

1. To measure the insertion loss of a bandpass or highpass filter that is
designed for 70cm, do I recalibrate using nanosaver to the design range of
the filter, or use the very wide range that was set to my internal
calibration of the unit.?

If I want to know how much loss the 70 cm. filter has inside it's passband
or targeted use frequency, should I recalibrate using 400 to 500 MHz sweep
range, instead of the 'base' calibration I did which used 50 KHz to 1000
MHz?

On the other hand, when I want to evaluate a 2m/70cm duplexer's
performance, I'm not so much looking at insertion loss as I am attenuation
of the 2m signal by the 70cm port (to prevent desense of the 2m receiver by
the 70cm uplink transmitter). I am seeing about 56 dB of rejection by the
duplexer's 70cm port, at 145.9 MHz (Non-used 2m port terminated in 50
Ohms.

I am also seeing about 8 dB more rejection of the 70cm uplink on 2m using a
Triplexer (HF/2M/70cm) LP-BP-HP, as a filter instead of the duplexer
(LP/HP). Is that expected behavior?

2. The default value in the Sweep control for what appears to be resolution
is 1, I have played with various values from 1 to 10. Obviously, the
display is much smoother with larger numbers, but it this a change in
resolution (of the data measurement) or is just a display trick? Do I get
better precision using a number greater than 1?

Thanks for your help, this little unit is a ham's dream come true.

73, N0AN
Hasan

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

On Mon, 14 Sep 2020 at 16:16, John Baines via groups.io <jbaines=
[email protected]> wrote:

Hi all,

Alan Victor gave an analysis with R in series with L but no R in series
with C. After some nasty algebra he derived an expression with sqrt (1-
CR*2/L) in the denominator. This is zero when R=sqrt (L/C) and
therefore resonant frequency ( defined as the frequency at which there is
no reactive component) is zero.

No, there’s no reactance at any frequency, not just DC. So you could argue
that it is resonate at all frequencies.



This makes my brain hurt, but not as much as thinking what happens whenR

sqrt(L/C) and the frequency becomes Imaginary?

I have not looked at that.

Thanks David for re-energising my grey matter.

It’s an unusual idea.

BTW, for whoever said I should have wrote it in a fixed Width font, I don’t
know how to do it on my iPhone. I use the gmail app.

73

John

M0JBA

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,

Sorry, my first guess was (wildly) wrong as must have been my vector diagrams.

Alan Victor gave an analysis with R in series with L but no R in series with C. After some nasty algebra he derived an expression with sqrt (1- CR*2/L) in the denominator. This is zero when R=sqrt (L/C) and therefore resonant frequency ( defined as the frequency at which there is no reactive component) is zero. I did a similar analysis with R in series with both the L and C branches and after some even nastier algebra came up with a more complicated expression but again with sqrt (1- CR*2/L) in the denominator.

This makes my brain hurt, but not as much as thinking what happens whenR >sqrt(L/C) and the frequency becomes Imaginary?

Thanks David for re-energising my grey matter.

73
John
M0JBA

Looking at the SMS's with naked eye they appear ok. Like I stated on original post, the die goes on and off with no resistance at all. I can wiggle the die with all threads inside of die which to me seems like the connectors diameter is a little too small. Center female pin looks fine using small magnifying glass, but that's just my opinion since I do not have the proper tools for making measurements on SMS's.
THANK YOU ALL for your inputs !

Colin, are you getting the 6 to 8 hours of battery run time on yours?

Vidas

On Mon, 14 Sep 2020 at 03:03, K5TRP <trippsanders99@...> wrote:

Seems like a bad clone you should probably return it and buy a new one from
r and l electronics the distribute the offical v2, v2n, h, h4 nanovnas in
the us.

I can't imagine most sellers would want to accept a return if someone has
run a die down an SMA connector!

I recently had a male SMA load from Minicircuits which was out of
specification - the dielectric was too far forward, as measured on Maury
Microwave connector guages. So a poor thread is not the only possible
reason a connector may not screw on.

I buy thousands of Minicircuits parts, and this if the first I have had any
problems with.

73,

Tripp Sanders
K5TRP

Dave, G8WRB.

Yeah I knew that I guess I just forgot that hugen made standard v2’s.

On Sun, Sep 13, 2020 at 10:25 PM hwalker <herbwalker2476@...> wrote:

On Sun, Sep 13, 2020 at 07:03 PM, K5TRP wrote:



Seems like a bad clone you should probably return it and buy a new one
from r and l electronics the distribute the offical v2, v2n, h, h4 nanovnas
in the us.

=====================================

Tripp,

One clarification. R&L is a distributer for hugen's version of the V2
products in the US. The official V2 is distributed by the open source
developer. The developer is protective of claims of suggesting products
other than hers are official, so we monitor and make corrections to
maintain impartiality.



- Herb







--

73,
Tripp Sanders
K5TRP

I have never had such sma problems. I
Resume the problem was with both connectors and you used a lead ( or a cal standard) known to be ok?

I wonder if the centre recepticle has moved when the connector was soldered to the board and the dialectric is not ptfe ( which would haVe tolerated the heat). If you look directly over the recepticle, you might be able to see the eccentricity of the centre part.

Alternatively the internal diameter of the outer component is out of spec, but that is difficult to measure without specialist tools. You might be able to see tiny scratches in the gold plating of recepticle or attempted connecting device if you look with a magnifying glass, or one of those ultracheap “ microscopes” from China. I have found them invaluable.

With moderate soldering skills, it would not be impossible to replace the sma connectors. I am sure some people will need to do this in a year or so, as the sma connectors will have worn out with heavy use. That is why some put on male to female sacrificial” savers”, or get the more robust N version.

Steve L. G7PSZ

I have a nanoVNA-F that I am very pleased with.
I have done the internal calibration.

I use nanosaver software on Win10, and am also very pleased with it. Do I
recalibrate using the nanosaver software for every different band filter I
am testing and save that calibration using the nanosaver software?

1. To measure the insertion loss of a bandpass or highpass filter that is
designed for 70cm, do I recalibrate using nanosaver to the design range of
the filter, or use the very wide range that was set to my internal
calibration of the unit.?

If I want to know how much loss the 70 cm. filter has inside it's passband
or targeted use frequency, should I recalibrate using 400 to 500 MHz sweep
range, instead of the 'base' calibration I did which used 50 KHz to 1000
MHz?

On the other hand, when I want to evaluate a 2m/70cm duplexer's
performance, I'm not so much looking at insertion loss as I am attenuation
of the 2m signal by the 70cm port (to prevent desense of the 2m receiver by
the 70cm uplink transmitter). I am seeing about 56 dB of rejection by the
duplexer's 70cm port, at 145.9 MHz (Non-used 2m port terminated in 50 Ohms.

I am also seeing about 8 dB more rejection of the 70cm uplink on 2m using a
Triplexer (HF/2M/70cm) LP-BP-HP, as a filter instead of the duplexer
(LP/HP). Is that expected behavior?

2. The default value in the Sweep control for what appears to be resolution
is 1, I have played with various values from 1 to 10. Obviously, the
display is much smoother with larger numbers, but it this a change in
resolution (of the data measurement) or is just a display trick? Do I get
better precision using a number greater than 1?

Thanks for your help, this little unit is a ham's dream come true.

73, N0AN
Hasan

Hello,

Is it possible to use a CW command with NanoVNA Saver ?

Thank you for your help.

73 QRO,

Rudi, HB9ARI

Got mine from Seesii on amazon. As advertized and no issues.

Regards
Colin

NOW U GUYS TELL ME LOL !
I admit that I have very little patience when it comes to buying things, Wish I knew last month! I was thinking of just replacing those connectors but theirs always some fire I'm putting out and not enough hours in a day!
Ok, just setup an account with R&L and of course they are out of stock, oh well, now for the long wait lol
TNX for your fast replies,
73 N8AUM Vidas

On Fri, Sep 4, 2020 at 09:56 AM, Piero Tognolatti wrote:

Here is the figure from Carter paper (1932).

Can you please share PDF with this article from Carter?

Ted, I understand what ur trying to do but by cutting one of the cables will make it pretty short. Making antenna measurements for example with such a short cable might give you false readings because the antenna will be very close in proximity to you and all its surroundings. It's also best to pay more for adapters, couplers.... Most of the "cheap" stuff has virtually or no quality control. On very very low frequencies they will probably work but the higher in freq. you go the more things become noticeable. Hope that makes sense?
Good luck !
I

On Sun, Sep 13, 2020 at 07:03 PM, K5TRP wrote:

Seems like a bad clone you should probably return it and buy a new one from r and l electronics the distribute the offical v2, v2n, h, h4 nanovnas in the us.
=====================================
Tripp,
One clarification. R&L is a distributer for hugen's version of the V2 products in the US. The official V2 is distributed by the open source developer. The developer is protective of claims of suggesting products other than hers are official, so we monitor and make corrections to maintain impartiality.

- Herb

Seems like a bad clone you should probably return it and buy a new one from
r and l electronics the distribute the offical v2, v2n, h, h4 nanovnas in
the us.

On Sun, Sep 13, 2020 at 8:50 PM N8AUM via groups.io <n8aum=
[email protected]> wrote:

Hello all,

I purchased a SAA-V2 from Amazon's seller Seesii and BOTH the SMA's are
bad or wrong size or something? I can get about 3/4 of a turn before it
stops acting like wrong thread count so I decided to re thread it with a
proper die. The die went on and off too easy as if the SMA's diameter is a
little smaller than it should be. When I try connecting anything it just
doesn't "feel" right, it tries to screw on at a slight angle but if I align
it perfectly it will only get almost 3/4 turn. Just wondering if anyone
else has had this problem? Another thing I found was it claimed 6 to 8 hour
run time with the internal battery which I found wasn't even close. I
cycled the battery on 2 identical units 4 times and only got about 3.25
hours of run time. The seller quickly changed that to 3hrs on his listing
after I wrote him about my findings. He still has another listing for the
same SAA-V2 with the original claim of over 6hrs run time







--

73,
Tripp Sanders
K5TRP