开云体育

On Aug 27, 2023, at 21:56, Mark KQ4EKK <kq4ekk+groups@...> wrote:

?I am building different Un:Uns using different wiring schemes and caps. While testing a config, I noticed that my battery was down to one bar and I did not have the USB cable plugged in at the time. I was not keeping records at the time, just quick tests. So I did not have my nanovna H4 4.3 plugged in, not using Nanovna-App at the time. I just plugged it in and saw the plot change on the nano display. I went HMMMM. was i touching something? did I move something? No.

I started testing by unplugging the usb, and my original plot came back. Then I plugged it back in and back to same "changed" plot. Repeatable and always the same places the changed occurred.

Thought, maybe my cable is bad. Nope tried 3 different higher quality cables and exact same results. Did the same test on PC directly and not on the usb expansion bar (maybe it introduces the problem). Nope, same plot changes on pc directly to nanovna with all 3 cables. OK, maybe some ferrites will help. Put on 2 Fair-rite type 31 beads (purchased from Mouser, not amazon or ebay!), same changes.

ok remove pc from the equation... I tested on a laptop with battery only, no outside electricity. Desktop on laptop has no apps open (nanovna-app) or anything. Simply plugging in the usb cable changes the plot on the nanovna, not the same but very similar change to the pc plugged in change.

I also let the nanovna FULLY charge while turned off and then tested again. Simply plugging into an external power source via the usb is causing the issue.

Has anyone seen this before? Do you think that the battery charging circuit in the vna is causing the issue (before I examine this further)?

Some details about the nanovna. Nanovna H4. HW version 4.3_MS
It was purchased via Amazon from the AURSINC store, which was listed on the nanovna.com site as a authentic seller.
I have looked inside the unit and it is clean and well manufactured. Clean solder points and the unit arrived in the official box with all parts.
I believe this to be an authentic unit and not clone.

The errors are shown across the whole spectrum but are very low at low frequencies and grow exponentially higher with higher frequencies. I am doing a S21 logmag plot from 1MHz to 30MHz. There also seems to be large shift (jump down) around 15MHz.

Any thoughts would be welcomed.

Thanks in advance,
Mark

The AM radio in my car works just fine. Chevy BoltEV.
How short our memories are - does nobody else remember "alternator noise"?
Cars are mobile noise generators.

73,
-Rick

On Sat, Aug 26, 2023 at 9:47?PM N7RWB Craig Cherry via groups.io
<craig.cherry@...> wrote:

Ken, looking through FCC part 15 rules on emissions, I don’t see any
exemption for electric car motors or power systems. Do you have a

reference

to a FCC document for the exemption you mentioned?

--
Rick Murphy, D. Sc., CISSP-ISSAP, K1MU/4, Annandale VA USA

Document the issues.
Send a copy to the FCC.
If no action is taken, take the vehicle to the Green bank observatory and park it for a while.
That should get some attention.

Glenn


On 8/27/2023 2:21 PM, Dragan Milivojevic wrote:

Document your findings in a blog post and spread the word?
They will do nothing without media exposure.

On Sun, 27 Aug 2023 at 19:22, W0LEV<davearea51a@...>? wrote:

I don't like to be the bearer of bad news, but the dealership has no idea
what RFI is.? They know the words and there is a problem with some Jeep
models, but that's as far as they go.? Experience follows:

While somewhat of an esoteric problem with RFI:? the "Water Hole"
surrounding 1420.405751 MHz.? This is the emission line of celestial and
deep space hydrogen designated by HI.? The Water Hole is protected spectrum
by international agreement, including the US.? Well,......., read on.

We have a 2018 Jeep JL Rubicon.? It, of course, includes the capability of
serving as a hotspot for the internet and making cell phone calls.? As
such, it contains a cell modem as part of the electronics behind the video
display in the dash.? That modem operates at nominally 700 MHz (I've easily
detected its fundamental frequency output on the spectrum analyzer) .? The
second harmonic screams out of the assembly and blankets the hydrogen line
such that I can not do radio astronomy on that frequency.? It ceases
"looking for mommie" - finding a cell tower as we have no cell coverage at
home - after sitting untraveled for 3 or 4 days.? Does it track my
travels?? Absolutely yes, but that's a different problem.

I have four times contacted the local dealership where we bought the
vehicle.? They have absolutely no inkling of what I'm talking about other
than recognizing the term "Radio Frequency Interference". I've sent Jeep
in Toledo - their engineering department - three letters documenting,
screen grabs, the interference both as captured on the spectrum analyzer of
the second harmonic of the cell modem and in the time domain from my
receiver as captured on the laptop at 1420 MHz (after some downconversion
and detection).? There has been absolutely no response from them, either,
other than a form email "thanking me for my interest in Jeep".........which
we already own.? Thanks, but no thanks!

Frustrated......??? Yes.......!? There are instructions online on disabling
the cell modem, but since we camp off-grid in many...many locations which
do not have any cell coverage or amateur repeaters, I'm reluctant to do
so.? In addition, it involves literally taking the whole dash apart which
I'm not into attempting.

All I can communicate is, "good luck"........and, there really is no such
thing as "luck".? YMMV......?

Dave - W?LEV

On Sat, Aug 26, 2023 at 11:49?PM Glenn Little<glennmaillist@...>
wrote:

Take it back to the dealer and insist that they fix the problem.

The problem is poorly designed and implemented inverters for the battery
and electronics.
It probably does not meet part 15 FCC rules for unintentional radiators.

Glenn


On 8/26/2023 12:59 PM, Donald S Brant Jr wrote:

If you are describing a problem with AM reception, it could be EMI from

all of the inverters, etc. in the car, interfering with reception, rather
than an antenna issue.? I had heard that car makers were trying to move
away from having AM to side step this issue.? 73, Don N2VGU

--
-----------------------------------------------------------------------

Glenn Little??????????????? ARRL Technical Specialist QCWA? LM 28417
Amateur Callsign:WB4UIVwb4uiv@...????? AMSAT LM 2178
QTH:? Goose Creek, SC USA (EM92xx)? USSVI, FRA, NRA-LM ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"

--

*Dave - W?LEV*


--
Dave - W?LEV

Document your findings in a blog post and spread the word?
They will do nothing without media exposure.

On Sun, 27 Aug 2023 at 19:22, W0LEV<davearea51a@...> wrote:

I don't like to be the bearer of bad news, but the dealership has no idea
what RFI is. They know the words and there is a problem with some Jeep
models, but that's as far as they go. Experience follows:

While somewhat of an esoteric problem with RFI: the "Water Hole"
surrounding 1420.405751 MHz. This is the emission line of celestial and
deep space hydrogen designated by HI. The Water Hole is protected spectrum
by international agreement, including the US. Well,......., read on.

We have a 2018 Jeep JL Rubicon. It, of course, includes the capability of
serving as a hotspot for the internet and making cell phone calls. As
such, it contains a cell modem as part of the electronics behind the video
display in the dash. That modem operates at nominally 700 MHz (I've easily
detected its fundamental frequency output on the spectrum analyzer) . The
second harmonic screams out of the assembly and blankets the hydrogen line
such that I can not do radio astronomy on that frequency. It ceases
"looking for mommie" - finding a cell tower as we have no cell coverage at
home - after sitting untraveled for 3 or 4 days. Does it track my
travels? Absolutely yes, but that's a different problem.

I have four times contacted the local dealership where we bought the
vehicle. They have absolutely no inkling of what I'm talking about other
than recognizing the term "Radio Frequency Interference". I've sent Jeep
in Toledo - their engineering department - three letters documenting,
screen grabs, the interference both as captured on the spectrum analyzer of
the second harmonic of the cell modem and in the time domain from my
receiver as captured on the laptop at 1420 MHz (after some downconversion
and detection). There has been absolutely no response from them, either,
other than a form email "thanking me for my interest in Jeep".........which
we already own. Thanks, but no thanks!

Frustrated......? Yes.......! There are instructions online on disabling
the cell modem, but since we camp off-grid in many...many locations which
do not have any cell coverage or amateur repeaters, I'm reluctant to do
so. In addition, it involves literally taking the whole dash apart which
I'm not into attempting.

All I can communicate is, "good luck"........and, there really is no such
thing as "luck". YMMV......?

Dave - W?LEV

On Sat, Aug 26, 2023 at 11:49?PM Glenn Little<glennmaillist@...>
wrote:

Take it back to the dealer and insist that they fix the problem.

The problem is poorly designed and implemented inverters for the battery
and electronics.
It probably does not meet part 15 FCC rules for unintentional radiators.

Glenn


On 8/26/2023 12:59 PM, Donald S Brant Jr wrote:

If you are describing a problem with AM reception, it could be EMI from

all of the inverters, etc. in the car, interfering with reception, rather
than an antenna issue. I had heard that car makers were trying to move
away from having AM to side step this issue. 73, Don N2VGU

--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign:WB4UIVwb4uiv@... AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI, FRA, NRA-LM ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"

--

*Dave - W?LEV*


--
Dave - W?LEV

I don't like to be the bearer of bad news, but the dealership has no idea
what RFI is. They know the words and there is a problem with some Jeep
models, but that's as far as they go. Experience follows:

While somewhat of an esoteric problem with RFI: the "Water Hole"
surrounding 1420.405751 MHz. This is the emission line of celestial and
deep space hydrogen designated by HI. The Water Hole is protected spectrum
by international agreement, including the US. Well,......., read on.

We have a 2018 Jeep JL Rubicon. It, of course, includes the capability of
serving as a hotspot for the internet and making cell phone calls. As
such, it contains a cell modem as part of the electronics behind the video
display in the dash. That modem operates at nominally 700 MHz (I've easily
detected its fundamental frequency output on the spectrum analyzer) . The
second harmonic screams out of the assembly and blankets the hydrogen line
such that I can not do radio astronomy on that frequency. It ceases
"looking for mommie" - finding a cell tower as we have no cell coverage at
home - after sitting untraveled for 3 or 4 days. Does it track my
travels? Absolutely yes, but that's a different problem.

I have four times contacted the local dealership where we bought the
vehicle. They have absolutely no inkling of what I'm talking about other
than recognizing the term "Radio Frequency Interference". I've sent Jeep
in Toledo - their engineering department - three letters documenting,
screen grabs, the interference both as captured on the spectrum analyzer of
the second harmonic of the cell modem and in the time domain from my
receiver as captured on the laptop at 1420 MHz (after some downconversion
and detection). There has been absolutely no response from them, either,
other than a form email "thanking me for my interest in Jeep".........which
we already own. Thanks, but no thanks!

Frustrated......? Yes.......! There are instructions online on disabling
the cell modem, but since we camp off-grid in many...many locations which
do not have any cell coverage or amateur repeaters, I'm reluctant to do
so. In addition, it involves literally taking the whole dash apart which
I'm not into attempting.

All I can communicate is, "good luck"........and, there really is no such
thing as "luck". YMMV......?

Dave - W?LEV

On Sat, Aug 26, 2023 at 11:49?PM Glenn Little <glennmaillist@...>
wrote:

Take it back to the dealer and insist that they fix the problem.

The problem is poorly designed and implemented inverters for the battery
and electronics.
It probably does not meet part 15 FCC rules for unintentional radiators.

Glenn


On 8/26/2023 12:59 PM, Donald S Brant Jr wrote:

If you are describing a problem with AM reception, it could be EMI from

all of the inverters, etc. in the car, interfering with reception, rather
than an antenna issue. I had heard that car makers were trying to move
away from having AM to side step this issue. 73, Don N2VGU

--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIVwb4uiv@... AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI, FRA, NRA-LM ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"

--

*Dave - W?LEV*


--
Dave - W?LEV

Please note: lists Ali Express / Zeenko. This is no longer available, Zeenko is selling no products currently.

I tried ordering via Ali Express some months ago, a few days after successfully buying an AT-100M on Ali Express, to be told that they could no longer accept my Visa card, which has worked and still works for many years without any problems. I thus cannot recommend Ali Express in general thus with a 50% success rate only, as their systems are odd.

However, can the above page be updated, and are there any others that are not listed and reputable? The prices vary substantially, the Ali Express was the best price via Zeenko before.

Thank you