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To further W0LEV’s point, a good friend of mine works for that manufacturer, specifically on that truck, and said that the EMI from the PWM controllers in powertrain and battery management system was a large consideration for the decision to disable AM on the radio stack. Additionally the radios are now SDR based and have highly sensitive basically wide open RF front ends.

My personal experience is that EV manufacturers struggle with EMI, some more than others. I’ve been totally “blown off the air” on 10m by a passing Rivian truck. I also know several hams with Tesla vehicles who don’t seem to be plagued by this issue. YMMV...

In my own truck, RAM 1500, a simple aftermarket upgrade has caused a mess of EMI while the engine is running. Who would have thought those performance coil packs would cause so much noise!!!

Anyway, I run the risk of diverting too far from the original post for this thread..

Larry, the central pin “is” the resonant element, as compared to the baofeng antenna. The body of the vehicle is the ground plane. So in measuring that antenna, you could unplug it from the radio stack where both conductors are present and use some sort of adapter to make the connection to your nanovna. A measurement of an antenna system should include the transmission line as well, right? By comparison, the baofeng antenna outer shield connects to the radio body and capacitively to your hand to make the ground plane. (or via a tiger tail, but that’s a different discussion)

For a receive only antenna, the impedance match is not super important. These antenna are all compromise antenna and suffer accordingly. The nanovna will provide data points for impedance etc., but its not very helpful for understanding the difference in reception. Furthering what W6PAP said, for receive you are best served by an S-meter or a spectrum analyzer. Heck you might actually be able to quantify potential EMI frequencies with the truck “on” verses “off” with the analyzer.

For some things to check, verify that the body panel the antenna is mounted on is properly bonded to the rest of the vehicle. Bad ground = poor ground plane. That can change the dynamics of the antenna for certain. Hope that helps and have a great day!

-Ben

Pasternack made a high quality product when the company I worked for used them about 20 years ago. Good chance it is still a high quality product, at a higher price.
Recently I have ordered components from Newark and Digi-Key. I have a higher level of confidence with them, compared to most of the products that overwhelm Amazon. For components like resistors, capacitors, etc I like to see data sheets and refer to the manufacturers website to see the entire product line. I don't want a generic part. Connectors and intra-series adapters require attention to detail. A high tolerance adapter good to 10 GHZ can be expensive. If you need just 10 MHz a less expensive one or even a generic one might be fine. Cables are a bit more murky. I recently purchased part number 250-086 from Digi-Key. Too soon to comment on durability.

Hello Stan,

What model, manufacurer and from what supplier did you obtain the quality
sma coax cables?

Thanks.
Al

On Wed, Sep 6, 2023, 4:11 PM Stan Dye <standye@...> wrote:

It is not uncommon for the sma-terminated pigtail cables that come with

the

nanovna to fail, or to not have been assembled well. Sometimes the

shield

is not soldered at the connector, so it passes test at the factory, but
fails the first time you bend it. I ordered a set of better sma pigtail
cables, and haven't had a problem with them.

On Wed, Sep 6, 2023, 2:51 PM Allan Johnston <adhjohnston@...>

wrote:

Dave, W0LEV,

It's looking like an intermittent good then bad connection with the
NanoVNA.

The nanovna is connected with the unit's supplied connectors/coax and
additional connector as needed for the antenna.
See attached "nanovna usual bad trace" jpeg that shows the connectors.
The RigExpert connection does not include the small diameter nanovna

coax

cable.

As I set up the RigExpert and NanoVNA for review and photos I

discovered

the flaky intermittent connection in the run of small coax and

connectors.

The bad connection is so random that I cannot tell what connector is

the

problem.
More hunting!

Thank you for your response. Your questions helped me discover what is
biting me. At least I know the NanoVNA is working.
If you or anyone else has comments on the trace or the
equipment/coax/connector setup that may help me out then please don't
hesitate to respond.

Al. KA0VIA

On Wed, Sep 6, 2023 at 12:31?PM W0LEV <davearea51a@...> wrote:

How are you connecting the NANOVNA? Identical to the method used for

the

RigExpert? Where does the trace show on the Smith Chart of the

NANOVNA?

Is the trace consistent with the SWR indication?

Once your NANOVNA is calibrated, have you gone back with your cal.
standards and verified the calibration took correctly? Have you

verified

your cal. standards on the RigExpert or some other method?

I know.....just a bunch of questions, but I'm searching for possible
problems.

Dave - W?LEV

On Wed, Sep 6, 2023 at 5:27?PM Allan Johnston <adhjohnston@...

wrote:

The Nanovna h4 in use was purchased from R&L Electronics a year or

so

ago.

Last month I updated the software.
The Nanovna has never given me "good" results as compared to a

RigExpert

AA 650 zoom when measuring HF, VHF or UHF antennas.
The Nanovna has been calibrated for each frequency range. The

RigExpert

AA-650 zoom passes the self test.
Example; the Rigexpert reads a SWR of close to 1:1 for a 2 meter

antenna

that is externally mounted while the Nanovna results show 50:1.

Any ideas?
Thanks,
Al, KA0VIA

--

*Dave - W?LEV*


--
Dave - W?LEV

It is not uncommon for the sma-terminated pigtail cables that come with the
nanovna to fail, or to not have been assembled well. Sometimes the shield
is not soldered at the connector, so it passes test at the factory, but
fails the first time you bend it. I ordered a set of better sma pigtail
cables, and haven't had a problem with them.

On Wed, Sep 6, 2023, 2:51 PM Allan Johnston <adhjohnston@...> wrote:

Dave, W0LEV,

It's looking like an intermittent good then bad connection with the
NanoVNA.

The nanovna is connected with the unit's supplied connectors/coax and
additional connector as needed for the antenna.
See attached "nanovna usual bad trace" jpeg that shows the connectors.
The RigExpert connection does not include the small diameter nanovna coax
cable.

As I set up the RigExpert and NanoVNA for review and photos I discovered
the flaky intermittent connection in the run of small coax and

connectors.

The bad connection is so random that I cannot tell what connector is the
problem.
More hunting!

Thank you for your response. Your questions helped me discover what is
biting me. At least I know the NanoVNA is working.
If you or anyone else has comments on the trace or the
equipment/coax/connector setup that may help me out then please don't
hesitate to respond.

Al. KA0VIA

On Wed, Sep 6, 2023 at 12:31?PM W0LEV <davearea51a@...> wrote:

How are you connecting the NANOVNA? Identical to the method used for

the

RigExpert? Where does the trace show on the Smith Chart of the

NANOVNA?

Is the trace consistent with the SWR indication?

Once your NANOVNA is calibrated, have you gone back with your cal.
standards and verified the calibration took correctly? Have you

verified

your cal. standards on the RigExpert or some other method?

I know.....just a bunch of questions, but I'm searching for possible
problems.

Dave - W?LEV

On Wed, Sep 6, 2023 at 5:27?PM Allan Johnston <adhjohnston@...>
wrote:

The Nanovna h4 in use was purchased from R&L Electronics a year or so

ago.

Last month I updated the software.
The Nanovna has never given me "good" results as compared to a

RigExpert

AA 650 zoom when measuring HF, VHF or UHF antennas.
The Nanovna has been calibrated for each frequency range. The

RigExpert

AA-650 zoom passes the self test.
Example; the Rigexpert reads a SWR of close to 1:1 for a 2 meter

antenna

that is externally mounted while the Nanovna results show 50:1.

Any ideas?
Thanks,
Al, KA0VIA

--

*Dave - W?LEV*


--
Dave - W?LEV

Dave, W0LEV,

It's looking like an intermittent good then bad connection with the
NanoVNA.

The nanovna is connected with the unit's supplied connectors/coax and
additional connector as needed for the antenna.
See attached "nanovna usual bad trace" jpeg that shows the connectors.
The RigExpert connection does not include the small diameter nanovna coax
cable.

As I set up the RigExpert and NanoVNA for review and photos I discovered
the flaky intermittent connection in the run of small coax and connectors.
The bad connection is so random that I cannot tell what connector is the
problem.
More hunting!

Thank you for your response. Your questions helped me discover what is
biting me. At least I know the NanoVNA is working.
If you or anyone else has comments on the trace or the
equipment/coax/connector setup that may help me out then please don't
hesitate to respond.

Al. KA0VIA

On Wed, Sep 6, 2023 at 12:31?PM W0LEV <davearea51a@...> wrote:

How are you connecting the NANOVNA? Identical to the method used for the
RigExpert? Where does the trace show on the Smith Chart of the NANOVNA?
Is the trace consistent with the SWR indication?

Once your NANOVNA is calibrated, have you gone back with your cal.
standards and verified the calibration took correctly? Have you verified
your cal. standards on the RigExpert or some other method?

I know.....just a bunch of questions, but I'm searching for possible
problems.

Dave - W?LEV

On Wed, Sep 6, 2023 at 5:27?PM Allan Johnston <adhjohnston@...>
wrote:

The Nanovna h4 in use was purchased from R&L Electronics a year or so

ago.

Last month I updated the software.
The Nanovna has never given me "good" results as compared to a

RigExpert

AA 650 zoom when measuring HF, VHF or UHF antennas.
The Nanovna has been calibrated for each frequency range. The RigExpert
AA-650 zoom passes the self test.
Example; the Rigexpert reads a SWR of close to 1:1 for a 2 meter

antenna

that is externally mounted while the Nanovna results show 50:1.

Any ideas?
Thanks,
Al, KA0VIA

--

*Dave - W?LEV*


--
Dave - W?LEV

Dave, W0LEV,

It's looking like an intermittent good then bad connection with the
NanoVNA.

The nanovna is connected with the unit's supplied connectors/coax and
additional connector as needed for the antenna.
See attached "nanovna usual bad trace" jpeg that shows the connectors.
The RigExpert connection does not include the small diameter nanovna coax
cable.

As I set up the RigExpert and NanoVNA for review and photos I discovered
the flaky intermittent connection in the run of small coax and connectors.
The bad connection is so random that I cannot tell what connector is the
problem.
More hunting!

Thank you for your response. Your questions helped me discover what is
biting me. At least I know the NanoVNA is working.
If you or anyone else has comments on the trace or the
equipment/coax/connector setup that may help me out then please don't
hesitate to respond.

Al. KA0VIA

On Wed, Sep 6, 2023 at 12:31?PM W0LEV <davearea51a@...> wrote:

How are you connecting the NANOVNA? Identical to the method used for the
RigExpert? Where does the trace show on the Smith Chart of the NANOVNA?
Is the trace consistent with the SWR indication?

Once your NANOVNA is calibrated, have you gone back with your cal.
standards and verified the calibration took correctly? Have you verified
your cal. standards on the RigExpert or some other method?

I know.....just a bunch of questions, but I'm searching for possible
problems.

Dave - W?LEV

On Wed, Sep 6, 2023 at 5:27?PM Allan Johnston <adhjohnston@...>
wrote:

The Nanovna h4 in use was purchased from R&L Electronics a year or so

ago.

Last month I updated the software.
The Nanovna has never given me "good" results as compared to a

RigExpert

AA 650 zoom when measuring HF, VHF or UHF antennas.
The Nanovna has been calibrated for each frequency range. The RigExpert
AA-650 zoom passes the self test.
Example; the Rigexpert reads a SWR of close to 1:1 for a 2 meter

antenna

that is externally mounted while the Nanovna results show 50:1.

Any ideas?
Thanks,
Al, KA0VIA

--

*Dave - W?LEV*


--
Dave - W?LEV

How are you connecting the NANOVNA? Identical to the method used for the
RigExpert? Where does the trace show on the Smith Chart of the NANOVNA?
Is the trace consistent with the SWR indication?

Once your NANOVNA is calibrated, have you gone back with your cal.
standards and verified the calibration took correctly? Have you verified
your cal. standards on the RigExpert or some other method?

I know.....just a bunch of questions, but I'm searching for possible
problems.

Dave - W?LEV

On Wed, Sep 6, 2023 at 5:27?PM Allan Johnston <adhjohnston@...>
wrote:

The Nanovna h4 in use was purchased from R&L Electronics a year or so

ago.

Last month I updated the software.
The Nanovna has never given me "good" results as compared to a RigExpert
AA 650 zoom when measuring HF, VHF or UHF antennas.
The Nanovna has been calibrated for each frequency range. The RigExpert
AA-650 zoom passes the self test.
Example; the Rigexpert reads a SWR of close to 1:1 for a 2 meter antenna
that is externally mounted while the Nanovna results show 50:1.

Any ideas?
Thanks,
Al, KA0VIA

--

*Dave - W?LEV*


--
Dave - W?LEV

The Nanovna h4 in use was purchased from R&L Electronics a year or so ago.
Last month I updated the software.
The Nanovna has never given me "good" results as compared to a RigExpert
AA 650 zoom when measuring HF, VHF or UHF antennas.
The Nanovna has been calibrated for each frequency range. The RigExpert
AA-650 zoom passes the self test.
Example; the Rigexpert reads a SWR of close to 1:1 for a 2 meter antenna
that is externally mounted while the Nanovna results show 50:1.

Any ideas?
Thanks,
Al, KA0VIA

JJ Night
To answer your question…

There is nothing special about this antenna, other than it is a closed
LOOP of 140 ft heavy wire #10 because I had a few hundred feet of this wire.

I wanted good daytime NVIS antenna for prop of only a few hundred miles
from Phila around 10AM to 2 PM.
I was not interested in a low-angle DX signal for evening use (I have a
vertical that does that well)

The amount of wire did not matter too much (120-140 ft to start).
I feed this with about 75 ft of RG213 (nothing special)
The shape is a rectangle, only 20 ft or so above ground. I had a few big
strong trees as tie points.

I tried a 4:1 balun at first (thinking impedance of 100 ohms) and that did
not work well.
I replaced that with a simple 1:1 BALUN (choke).
At the low height above ground, I expected a lower impedance than putting
it up 50 ft.

I could attach the Nano VNA right at the feedpoint - direct - to avoid the
feedline messing with impedance.

I then hooked it up to a CLC Tuner (in my shack) in case the SWR was high
at the digi part of the band.
Because I had about 140 ft wire in the loop, the resonant point was just
below 7 MHz (about 6.8 MHz).
It worked fine for two weeks, but then I thought maybe I could improve it
by shortening it.
I pruned it back about 10 feet (harder to do for me on a 90 degree day)
and then I saw that the minimum SWR fell around 7.1 MHz, right where I
wanted it.

The NANO VNA that I own is already 3 years old (Amazon model) and I’m
using NANO VNA SAVER app on a Win10 (10 yr old) desktop. I had to make the
CALIB first with a 3-30 MHz span at a 10x mag. That took a few minutes to
do the OPEN, SHORT, and 50 0hm LOAD with the standards that came with the
rig.
I did a sweep from 3-30 MHz using the 50 ohm standard and everything
looked perfect on the 6 graphs.
That was reassuring!

The closed loop works far better than a pair of Hamsticks mounted
horizontally (14 ft total). Well, obviously!
It works just about as well as a simple 66 ft Inverted V center-fed dipole
(my standard) but I see much less QSB on the closed loop than from the
dipole. I like to use 7047 kHz W1AW CW bulletins as my standard to compare
antennas at 9AM to 10AM. And… it helps me copy CW by ear.

So nothing special about anything that I did.
I put in a CLC tuner in my shack, and this does sharpen up all of the
graphs, but I did not really need it.

My goal: see if I could build a better DAYTIME NVIS antenna for low part
of the 40m band.
I love the sound card digi modes and FLDIGI and am working on a new 40m
EMCOMM digi mode net which should begin on October 1st: Mid-Atlantic 40m
NBEMS net (7068 kHz vfo).
We plan to run this net every Sunday at 10AM to 11AM for a few months to
see how well “fickle forty” does at that hour with THOR22 (checkin) and
THOR56 (traffic). We know that 80m collapses by 10 AM for NVIS.

I really did not need a Nano VNA to build and test this antenna. I am now
doing A/B tests to see if folks I work on 40m digi modes can hear any
differences between the closed loop and Inverted V simple dipole.
I took the back-to-back Hamsticks down (may be good for a portable setup)
And I still have a 36 ft vertical with two above ground radials (upside
down T) for evening DX.

What are you trying to accomplish in your antenna?
Without the SAVER software, I’d be lost (color blind).

de k3eui Barry
near Philly
Sept 06 2023

On Sep 6, 2023, at 6:10 AM, Fran?ois <18471@...> wrote:

?

I put in a CLC tuner in my shack,

Please wat is a "CLC tuner" ?
--
F1AMM
Fran?ois

-----Message d'origine-----

De la part de Barry K3EUI
Envoyé : mercredi 6 septembre 2023 13:59