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I recently purchased an SV4401A from Aliexpress for $299. As a lab instrument, it is very nice, a giant step up from the F-V2. With up to 1001 data points, the sweep resolution is great. The N connectors are nice too, though a cal set of N types would have topped it off. It has mass and is ruggedly built, inside and out. The batteries are replaceable without soldering.
My unit has two serious issues, which I am trying to work through with the tech guy at Sysjojnt, who also developed the V2. The software nanovna-saver is picky about which Win10 pcs it'll run on. I get a failed to execute script msg. Strangely it runs on my cheap tablet and a desktop at work. Three others will not work. I am not a pc or Windows expert. Maybe there is a setting that will let it run? The other issue I have is that, when left off for a while unplugged, it will not boot. Instead, it cycles through a power on sequence indefinitely. The batteries are fully charged. So to take it outside I must bring a 5VDC power source with type C USB connector. Whether these problems are design flaws or just with my unit remains to be seen.
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On 14/08/2022 21:24, Ken Bozarth wrote: I recently purchased an SV4401A from Aliexpress for $299. As a lab instrument, it is very nice, a giant step up from the F-V2. With up to 1001 data points, the sweep resolution is great. The N connectors are nice too, though a cal set of N types would have topped it off. It has mass and is ruggedly built, inside and out. The batteries are replaceable without soldering.
My unit has two serious issues, which I am trying to work through with the tech guy at Sysjojnt, who also developed the V2. The software nanovna-saver is picky about which Win10 pcs it'll run on. I get a failed to execute script msg. Strangely it runs on my cheap tablet and a desktop at work. Three others will not work. I am not a pc or Windows expert. Maybe there is a setting that will let it run? The other issue I have is that, when left off for a while unplugged, it will not boot. Instead, it cycles through a power on sequence indefinitely. The batteries are fully charged. So to take it outside I must bring a 5VDC power source with type C USB connector. Whether these problems are design flaws or just with my unit remains to be seen. I wasn't happy with mine and sent it back for a refund. It only worked with the charger connected, the firmware seemed very limited compared to current models, and it wouldn't keep the date and time. It's actually an SMA unit inside, so the N connectors just add expense, and make the unit very heavy (including batteries). They even provide an SMA calibration set with adapters. I would liked to have kept the unit (that's why I bought it, and an N calibration set for another $125), but I feel it's not yet ready for prime time. The NanoVNA-F, LiteVNA 64 or NanoVNA V2 plus 4 are what I would recommend. Cheers, David -- SatSignal Software - Quality software for you Web: https://www.satsignal.euEmail: david-taylor@... Twitter: @gm8arv
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The NanoVNA-F, LiteVNA 64 or NanoVNA V2 plus 4 are what I would recommend.
David Concerning the nanoVNA-F which works very well alone and connected with nanaovna-saver under Win7, here is what Roger Need answered me https://groups.io/g/nanovna-users/message/29253The NanoVNA-F is not an open source design. The manufacturer does not publish schematics or source code for this product. I don't know if it can be important in the context of my OM use.-- François -----Message d'origine----- De la part de David J Taylor lundi 15 août 2022 09:59
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On 15/08/2022 09:22, F1AMM wrote: Concerning the nanoVNA-F which works very well alone and connected with nanaovna-saver under Win7, here is what Roger Need answered me
https://groups.io/g/nanovna-users/message/29253
The NanoVNA-F is not an open source design. The manufacturer does not publish schematics or source code for this product. I don't know if it can be important in the context of my OM use.--
François François, Being "open source" can allow others to provide updates which enhance the functionality of the hardware, and perhaps fix bugs left by the manufacturer. On the other hand, there seem to be many different firmware versions, leading to confusion among the users, and incompatibility with the Windows support programs. Open source can lead to: "Something only works with version X.X of the firmware, and Y.Y of the NanoVNA Saver. Oh, but I have version Z.Z of the firmware, so how do I upgrade? Oh, that's too complicated for me!" For me, open source is a "nice-to-have" feature. but it would not stop a purchase, assuming that a unit got generally good reviews. 73, David GM8ARV -- SatSignal Software - Quality software for you Web: https://www.satsignal.euEmail: david-taylor@... Twitter: @gm8arv
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On 8/15/22 2:18 AM, David J Taylor via groups.io wrote: On 15/08/2022 09:22, F1AMM wrote:
Concerning the nanoVNA-F which works very well alone and connected with nanaovna-saver under Win7, here is what Roger Need answered me
https://groups.io/g/nanovna-users/message/29253
The NanoVNA-F is not an open source design. The manufacturer does not publish schematics or source code for this product. I don't know if it can be important in the context of my OM use.--
François François,
Being "open source" can allow others to provide updates which enhance the
functionality of the hardware, and perhaps fix bugs left by the manufacturer.
On the other hand, there seem to be many different firmware versions, leading
to confusion among the users, and incompatibility with the Windows support
programs.
Open source can lead to: "Something only works with version X.X of the
firmware, and Y.Y of the NanoVNA Saver. Oh, but I have version Z.Z of the
firmware, so how do I upgrade? Oh, that's too complicated for me!"
For me, open source is a "nice-to-have" feature. but it would not stop a
purchase, assuming that a unit got generally good reviews.
73,
David GM8ARV After all Keysight/Agilent/HP are all closed source units, and quite popular; warts and all.
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On Mon, Aug 15, 2022 at 06:13 AM, Jim Lux wrote:
After all Keysight/Agilent/HP are all closed source units, and quite
popular; warts and all.
Yes Keysight/Agilent/HP they are closed source but have service depots/manuals, technical support, warranty and software updates to fix bugs and add new features. Most small Asian manufacturers have none of the above and users provide support to each other in forums like this. Third parties do the software development if the product is open sourced. If the product is closed source like the -F the user is lucky if they get a periodic bug fix or new features and if the hardware has a problem/failure you are out of luck. Roger
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Update to my SV4401A review - The tech guy said they are working to debug the nanovna-saver app. There seems to be a common script execution problem in Python programming. As for the power on issue, we are discussing possible battery issues. I will replace mine (I can always use a spare set of batteries). I am having better success with the power on problem by discharging the batteries somewhat. It seems that fully charged batteries may have a bit too much energy at power on that may be glitching the startup circuit. I wish I had the schematic, which I will ask for. More updates on that later. If I get home from work tonight and I am able to turn it on, then I'm getting somewhere. Stay tuned.
This instrument offers so much more than the original or the F model and I believe was mainly designed for lab use. Yes, it's only an F model in a big box with big screen and big connectors, but also more memory, more resolution and it even calculates matching networks for the measured impedance. I'll keep mine regardless of the outcome of the power up problem, and the software I'm sure will be fixed.
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Another update on my SV4401A...After letting the batteries discharge to about 80%, I can now power the unit on after letting it sit off and unplugged for 9 hrs. I charged the batteries back to 100%, left off for only 1 hour and it will not power up without the power source plugged in. These batteries are supposed to be 3.6V, now advertised at 3.7V with various mAHr ratings. I suspect that internal resistance of the batteries may be too low, causing a big current spike at turn on, which glitches some current limit circuit. Lower voltage does not source as high current spike. Not having the schematic, I can't tell exactly what the problem is. I will do more experiments on mine - different batteries and perhaps adding a low resistance in series with batteries, if I can wire one in somehow. Stay tuned.
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my final review...Battery experiments were futile. All batteries will show the power on problem when fully charged. My workaround if I need it in the field is to carry a phone charger with type C connector. Plug it in to power on, then unplug it while on. Or, if using closeby, unplug it from charger while on. After some use, it will function correctly. The designers should come up with a revision, hopefully simple enough for a DIY repair, but no guarantees. I use mine mainly in the lab where I have power. As for the buggy software, I can only hope they fix that too. If anyone does not see the power on issue, then please post.
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On the other hand, there seem to be many different firmware versions, leading
to confusion among the users, and incompatibility with the Windows support
programs. To read the thread https://groups.io/g/nanovna-users/message/29427NanoVNA App - Installation and Use #applications I believe you are right; it's to die for. Finally I did well to buy a nanoVNA-F. -- François -----Message d'origine----- De la part de David J Taylor lundi 15 août 2022 11:18
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One last review on the SV4401A. Here is the bottom line as it is shipping currently: There is a problem with power-on with a fully changed battery and no external power connection. This has been corrected with a resistor change - easy to do without special tools if you can solder. In a lab environment, you'd never know it has a problem, keeping it plugged in. The PC app nanovna-saver does not work correctly, if it even connects to your Win10 PC at all. The app has very limited use. I find that taking a snapshot of the unit's screen and saving it as an image file is the best. Maybe they will improve this app, as it would be more convenient to operate it from the PC if you want to save sweep files. Being as large and heavy as it is, it is not a good instrument to take outside for antenna measurements, in my opinion. I love all the extra memory locations for special calibrations! One weakness that must be fixed somehow is the USB-C jack, which has no mechanical support. If not made stronger, the port is certain to fail, breaking a connection on the PCB. I plan to put a drop of hot glue at this connector, fixing it to the chassis, meanwhile being very careful to support the USB cable while charging or transferring files. I bought mine from Aliexpress for $299, normally about $399. Some ham radio suppliers are gouging everyone at $599! If you like the nanovna-F, you'll love this one, even with the improvements you need to make.But what is the USB-A connector good for? It is only a power source, but for what purpose?
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About 2 weeks ago I purchased an AURSINC version of the SV4401A off Amazon. I do not experience the start-up problem with a fully charged battery, so they must have resolved that problem.
I also have an HP8753es and have made some simple comparisons. The SV4401A is pretty much in agreement with my HP8753es. I really need to do some more in depth comparisons.
Anyway, my biggest complain about the SV4401A is that it's slow, even when using a wide bandwidth and a narrow sweep range. This makes it a real pain in tuning a filter in the AM broadcast band while sweeping over a range of 100 kHz using the widest I.F. bandwidth offered. It seemed to take about 3 seconds per sweep update.
I'm interested in hearing other users experience in this matter.
Thanks,
Burt, K6OQK
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On Sun, Oct 8, 2023 at 09:55 AM, Burt K6OQK wrote:
my biggest complain about the SV4401A is that it's slow, even when using a
wide bandwidth and a narrow sweep range.
I am not familiar with that unit, but can you reduce the number of points enough to get an acceptable sweep time? You can use a fast but coarse sweep to get your tuning in the ballpark, then take a more detailed look when you are getting close. 73, Don N2VGU
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Ken,
I'm new to the group, but long time Ham. I have a used SV4401A on the way. Purchased on eBay, with no indication of any issues. Firmware is 5.1. You mentioned a resistor fix for the start up issue, but nothing about either on the value or location. 99% of what I want to do with this unit, is on battery and I don't have any current indcation that this issue will occure with mine. However, this post is over a year old.. So, I'm wondering if the battery start problem is no longer an isse? Thanks in advance.
Mike
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Hi Ken, I know this is a quite old post I was going through, as I was curious about experiences of this SV4401A. I just had a thought about power-up problem you have experienced in the past, and you suggesting a series resistor to limit the power-up inrush current. I was thinking maybe one can put a electrolytic capacitor of a sufficient (micro)Farad's to act as a "short" just after the power-up. That would diverge the start-up current to the capacitor. The issue has probably been solved in the meantime, but this is just an idea...
Still using the unit?
Cheers
Ernest
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Hi,
I recently encountered a startup problem with my SV4401A, which occurred after charging it. I purchased the unit 4 months ago, but it has recently failed. Despite following the procedure of removing resistor R180 and shorting its pads, the issue persists. The original value of the R180 resistor is 0 Ohm, so removing it and shorting its pads doesn't make sense unless its value has changed or maybe the revision was already implemented on my unit.
neb
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I received the entire series of devices for testing, and wrote a short review + comparisons here. NanoVNA F v2 / v3 https://groups.io/g/nanovna-beta-test/topic/sysjoint_nanovna_f_v2_and_v3/104224126SV4401A / SV6301A https://groups.io/g/nanovna-beta-test/topic/sysjoint_sv4401a_sv6301a/104244189Now some thoughts: F v2 and SV4401A are good options for the v2 series Next, the company decided to release a version up to 6.3 GHz and release F v3 / SV6301A, but in addition to replacing the generator (and a slight change in the code in terms of ranges), it was also necessary to select operating modes Similar phase/amplitude noise was present on the first LiteVNA engineering samples. Later, Hugen debugged the wiring of the generators, and the modes were selected. Which significantly reduced noise when measuring phase. LiteVNA provide better perfomance and measured dynamic range If anyone has an F v3, please take measurements of the condition after calibration, I still assume that I have a defective device (well, there should not be such results). I would like to have LiteVNA in a similar 7 inch form factor + case (plus fix problems in > 3.8GHz range), and adapt the interface to such a screen (a lot of work has already been done in this direction). In last LiteVNA hw fixed touch controller problems (used new controller T2046 (old HR2046) for reduce power usage then device power off, now current ~0.2uA, old controller take ~860uA and dischage battery). It is also necessary to improve thermal stability. My impressions of F v2/v3 are spoiled, in my opinion, by a very unresponsive interface. And although the screen is large, the graphics look bad due to the thick lines. Regarding the buttons or the rocker, I’m used to the rocker, and the buttons would be convenient to press if they were also located on top and were larger. From the side they are not very convenient to press. The location of the buttons on the front of the SV is quite convenient. Not possible calibrate touch (on F v3 need click ~5mm left for grab marker, and move marker .... so slow). I do not consider the functionality, since I made it for myself with the light, and I will consider it better. In the SV series it is well expanded, which I liked is the ability to load a trace from memory and work with it, comparing it with current measurements (for the Lite, you only make a trace, without the possibility of further changes and comparisons). I wanted to do something similar, but... not done yet.
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They are 2 or 3 miniature switches inside the unit, i was thinking maybe on of those switch may reset the power supply
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So the SV4401A of the Lite VNA 64? Which device is more reliable?
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Sorry..typos
I wanted to add ad more options anyway. What's the best bang for your buck? Maximum accurate dynamic range under 400mhz is the target too.
Lite VNA 64, SV4401A, NanoVNA V2 Plus4 or VNA6000?
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David J Taylor
Roger Need
Burt K6OQK
Donald S Brant Jr
Mike N6HTY
ErnestB