[ARCHIVED THREAD] - ANTENNA ANALYZER for $50 (Page 4 of 5)
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Quoted:
I ordered mine from Amazon and it is shielded. I did pay a little more to get it alot sooner, but I was impatient. 
ETA-- Amazon link |
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Before I bite the bullet, as a new ham who will (hopefully) be getting a dual band mobile radio soon and installing in a Jeep (see this thread), which would be more useful for checking antenna location, a nanovna, or a SWR/wattmeter?
I can see the nanovna being useful long term, but for trying to figure out optimal placement of an antenna in the near future, which should I buy first? An example of what I'm trying to figure out - In addition to the thread I started here (linked above), I have been looking through various Jeep forums. I see some people on Jeep forums say the cowl is the best place for an antenna, the spare tire mount has high SWR once the spare tire is replaced. I've seen others say that the spare tire mount is better, that the cowl and/or windshield hinge has too much metal near the antenna. I can't find it again, but I saw one discussion where people suggested against the front of the Jeep because of RF exposure to the driver. Add to the confusion (at least for me) some of the people are talking about ham antennas, others have CB antennas. If I were to buy an antenna that was a good height for both locations (cowl and spare tire mount), and test placement at the spare tire mount, at the tailgate hinge, at the cowl, at the windshield hinge, etc. what would be the preferred device, nanovna, SWR/wattmeter, or some other meter? |
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Before I bite the bullet, as a new ham who will (hopefully) be getting a dual band mobile radio soon and installing in a Jeep (see this thread), which would be more useful for checking antenna location, a nanovna, or a SWR/wattmeter? I can see the nanovna being useful long term, but for trying to figure out optimal placement of an antenna in the near future, which should I buy first? An example of what I'm trying to figure out - In addition to the thread I started here (linked above), I have been looking through various Jeep forums. I see some people on Jeep forums say the cowl is the best place for an antenna, the spare tire mount has high SWR once the spare tire is replaced. I've seen others say that the spare tire mount is better, that the cowl and/or windshield hinge has too much metal near the antenna. I can't find it again, but I saw one discussion where people suggested against the front of the Jeep because of RF exposure to the driver. Add to the confusion (at least for me) some of the people are talking about ham antennas, others have CB antennas. If I were to buy an antenna that was a good height for both locations (cowl and spare tire mount), and test placement at the spare tire mount, at the tailgate hinge, at the cowl, at the windshield hinge, etc. what would be the preferred device, nanovna, SWR/wattmeter, or some other meter? The nano will allow you to see the SWR curve throughout the band (frequency range) you select instead of having to dial the radio up and down the band and spot checking the SWR. I have antennas mounted on my Jeep TJ. do you have any opposition to drilling holes? My VHF/UHF antenna mount is on the top of the windshield frame on the passenger side. My HF/CB antenna mount is just above the passenger side tail light. ETA - Pics Attached File Attached File Attached File |
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Either will work for what you want to do. The nanovna is a much easier platform to use IMO. The nano will allow you to see the SWR curve throughout the band (frequency range) you select instead of having to dial the radio up and down the band and spot checking the SWR. I have antennas mounted on my Jeep TJ. do you have any opposition to drilling holes? My VHF/UHF antenna mount is on the top of the windshield frame on the passenger side. My HF/CB antenna mount is just above the passenger side tail light. ETA - Pics https://www.AR15.Com/media/mediaFiles/108158/DSCN5250_JPG-1143959.JPG https://www.AR15.Com/media/mediaFiles/108158/DSCN5251_JPG-1143961.JPG https://www.AR15.Com/media/mediaFiles/108158/DSCN5252_JPG-1143962.JPG I don't want to derail this thread, so I'll try to keep it short - I was originally opposed to drilling holes, but I'm warming up to the idea. I plan on keeping my Jeep until it doesn't run anymore, so I'm not concerned with how holes would affect trade-in value. Where you have yours in that picture is just about where I want mine, but I have an '07 JK. The tail lights on the JK are taller, so I'd have to go more to the side. They make a bracket for Jeeps up to and including '06 that goes behind the tail light, placing the antenna close to where yours is. Due to the changes to the '07 and up tail lights, I don't see any mounts like that for mine. I'll probably update my other thread shortly. |
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Gotta split this since im new
PT 1 Full disclosure, I have never been formally trained for or used a real VNA. I bought this as a learning tool to better understand a VNA and interpreting the information it provides when applied to anything RF. For me mostly antennas, cables, filters ie; relatively simple stuff Ive had mine for a few days now playing around with it. Apparently it came with the AA version. Antenna analyzer and only two traces. played with that with moderate success. I then figured out how to create the dfu file and flash it. So I flashed to the latest edy555 release, 0.3.1 well that had many upgrades and turned it into more of a vna instead of the AA. but I found it to be very erratic maybe unstable. One nice feature is firmware option to place the vna into DFU mode instead of jumping the board. This makes re-flashing a little less cumbersome. So I flashed to and early edy555 release 0.1.0 Its actually very nice to use but I cant vouch for accuracy since I have no lab equipment to verify with. BUT, I can say it is consistent. Its producing results that I would expect of the few portable HT antennas that I swept. |
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PT 2
It took me a few attempts to get the DFU file manager and the DFuSe software working correctly. Had to find and manually load the drivers to get everything communicating. One that was in order, creating the Dfu file was pretty painless as is reflashing the unit. Also been playing with the VNA Sharp both the first release and the latest V3.0 update. Its ok. I do notice that while connected to the laptop that changes on the VNA do not coordinate with the software and vice versa. might go to something different; thats the fun in it right? There were times that I was getting inconsistent results when plugged in and running on the software. I put chokes on the cable at both ends with no differences. Also changed to a better shielded cable I already had, still no difference. then I opened it up and found that I have a NON shielded version. I wonder how much of a difference this makes? has anyone compared between a shielded and NON versions? What were the results? I am also suspect of the standards they sent with it. The load is much longer in physical length than the other two standards. I think im going to play around with making my own standards and see if I can clean up the results. |
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Quoted:
I ordered mine from Amazon and it is shielded. I did pay a little more to get it alot sooner, but I was impatient.
ETA-- Amazon link Looks like this one is the safest bet. I'm seeing too many bad reviews for others on Amazon and bad feedback for others on eBay. Looks like everyone is just copying and pasting descriptions and using other peoples' pictures. Now off to YouTube to watch some more videos. |
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Does yours have the shielding? I was going to order from Amazon because I have a gift card, but several of the reviews for the ones that are around $50 state that they do not have the shielding even though the description says that they do. I might as well order from eBay if I can get it for < $50, shipped from US, and it has the shielding. Edit to add - do you have any links for good .stl files for cases for the one you received? My 3D printer has been collecting dust for a while, this is as good a reason as any to get it going again. Edit again - that seller's most recent feedback said there was no shielding on the one received. Quoted:
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Got mine in the mail today - yes, it's small - now to go back and read this thread from the beginning for some pointers, software, etc. And maybe fire up my 3D printer for a case. Looks like tomorrow I'll be playing with some of my antennas and feedlines... I was going to order from Amazon because I have a gift card, but several of the reviews for the ones that are around $50 state that they do not have the shielding even though the description says that they do. I might as well order from eBay if I can get it for < $50, shipped from US, and it has the shielding. Edit to add - do you have any links for good .stl files for cases for the one you received? My 3D printer has been collecting dust for a while, this is as good a reason as any to get it going again. Edit again - that seller's most recent feedback said there was no shielding on the one received. |
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I am taking a short break from the crisis in my life to clear my head, so reading the ham forum.
I got one that appears well shielded. The boards look very well done. I printed a well designed case for it. How many terminations are supposed to come with it. I got 2. Is it: short and 50 ohms and the open is just no termination at all. Not that this really matters at all in my life right now. |
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Just ordered this one, thanks! Looks like this one is the safest bet. I'm seeing too many bad reviews for others on Amazon and bad feedback for others on eBay. Looks like everyone is just copying and pasting descriptions and using other peoples' pictures. Now off to YouTube to watch some more videos. Quoted:
Quoted:
I ordered mine from Amazon and it is shielded. I did pay a little more to get it alot sooner, but I was impatient.
ETA-- Amazon link Looks like this one is the safest bet. I'm seeing too many bad reviews for others on Amazon and bad feedback for others on eBay. Looks like everyone is just copying and pasting descriptions and using other peoples' pictures. Now off to YouTube to watch some more videos. |
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Yep, a short, open and 50 Ohms is a complete calibration set. We had a set for an HP network analyzer at work. (Been a few years back.) |
| Can someone point me to a good tutorial on what an antenna analyzer does and how to read it beyond measuring SWR? I'm just a Tech right now and I have a VHF/UHF SWR meter, but I'm wondering if I'll need something like this when I get my General and get into HF. |
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Can someone point me to a good tutorial on what an antenna analyzer does and how to read it beyond measuring SWR? I'm just a Tech right now and I have a VHF/UHF SWR meter, but I'm wondering if I'll need something like this when I get my General and get into HF. to see the SWR curve over a wide frequency range is sooo much better than spot checking SWR at different freqs with a standard SWR meter. This is especially true for multi-band antennas like the Hustler BTV series of verticals or OCF dipoles etc.. The NanoVNA has been one of the best investments in radio equipment I've made in 30 years of operating. There are vids on the 'Tube on how to use the 'Nano. |
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I fo'd the other day. Found one on Amazon with shield for $50 & Prime shipping ( https://www.amazon.com/gp/product/B01HCXG7Y0 )
Should be here tomorrow. It might be interesting to do some side by side scan comparisons with the AA-170. Already planning to print a case on the ender 3 
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Mine arrived yesterday. The boot screen shows it has firmware from Oct 18, nanovna-h.
I played around with calibrating, checking SWR on my HT antennas, connecting to nanovna-saver, etc. At first I was concerned because the printing on the front of the case looked bad. I wondered if it was a return. It still had the screen protector on it, and it doesn't look scratched or abused. A few things I noticed from reading other reviews - it does have the shielding, and the LEDs are blue. I read in one review that LED color helps identify nanovnas that are cheaper (some have blue, some red, others green). I'm still brand new to all of this, but for what I paid, I'm happy. Off to watch more YouTube videos... |
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The one I ordered came in yesterday, but it did not have RF shielding. It got sent back & I reordered a slightly different version that should get here friday.
Back story: The ad was a bit oddly worded, they offered a "Type 1" and a "Type 2" with both black & white cases. "Type 2" only came in white. "Type 1" came in either black or white. The "Type 2" description clearly referenced not having an RF shield, and was described as coming with fewer accessories than the "Type 1". The black "Type 1" description clearly referenced the RF shield. The white "Type 1" wording was a bit different & did not specifically reference the RF shield at all. I had ordered a white "Type 1" figuring black vs white made no difference. It turns out the white "Type 1" came with accessories and a installed battery, but no RF shield. The black "Type 1" comes with RF shield and accessories but no battery (same price). After processing the return, I ended up ordering a black "Type 1" and a battery (hindsight, I could probably have gotten one with battery for about the same total dollars ($56.50) with a bit more looking ...) |
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Quoted:
The one I ordered came in yesterday, but it did not have RF shielding. It got sent back & I reordered a slightly different version that should get here friday. Back story: The ad was a bit oddly worded, they offered a "Type 1" and a "Type 2" with both black & white cases. "Type 2" only came in white. "Type 1" came in either black or white. The "Type 2" description clearly referenced not having an RF shield, and was described as coming with fewer accessories than the "Type 1". The black "Type 1" description clearly referenced the RF shield. The white "Type 1" wording was a bit different & did not specifically reference the RF shield at all. I had ordered a white "Type 1" figuring black vs white made no difference. It turns out the white "Type 1" came with accessories and a installed battery, but no RF shield. The black "Type 1" comes with RF shield and accessories but no battery (same price). After processing the return, I ended up ordering a black "Type 1" and a battery (hindsight, I could probably have gotten one with battery for about the same total dollars ($56.50) with a bit more looking ...) I am going to return the one that I bought from eBay that claimed it had a shield (but did not), and once I get the refund I will consider getting this one - I have some LiPo batteries that might just work with it. Interesting how this one does not seem to have the short, open, and dummy SMA pieces like most others do. |
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OK package in & things look better
It came with a plastic case & every thing looked intact. 
The same terminators seen in the photos were included even though not specifically mentioned in the ad. 
One is clearly a short, one clearly open and the other tested @ 49.8 ohms on my VOM 
Shielding definitely present ... 
and the battery is not. 
I attached a power pack to the USB C receptacle with the provided cord & powered it up. 
Having confirmed it seemed functional, I soldered in the battery I ordered which came in the same delivery. The battery was charged to 4.02 volts at the time of delivery & came with a small plug I cut off. 
No magic smoke got out during the process, so I guess I'm good to go with seeing how this functions. This is a link to the NanoVNA I ordered ($49.99), "TYPE 1 - Black color" (and the color makes a difference ...) https://www.amazon.com/gp/product/B07XYRPJML This is a link to the battery, $6.49, 3.7v 450 mAh. I don't know how honest the capacity rating is, but it did com charged https://www.amazon.com/gp/product/B07BTQKK91 |
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OK package in & things look better It came with a plastic case & every thing looked intact. http://www.skhowell.com/images/DSCN6275.jpg The same terminators seen in the photos were included even though not specifically mentioned in the ad. http://www.skhowell.com/images/DSCN6276.jpg One is clearly a short, one clearly open and the other tested @ 49.8 ohms on my VOM http://www.skhowell.com/images/DSCN6278.jpg Shielding definitely present ... http://www.skhowell.com/images/DSCN6280.jpg and the battery is not. http://www.skhowell.com/images/DSCN6284.jpg I attached a power pack to the USB C receptacle with the provided cord & powered it up. http://www.skhowell.com/images/DSCN6287.jpg Having confirmed it seemed functional, I soldered in the battery I ordered which came in the same delivery. The battery was charged to 4.02 volts at the time of delivery & came with a small plug I cut off. http://www.skhowell.com/images/DSCN6287.jpg No magic smoke got out during the process, so I guess I'm good to go with seeing how this functions. This is a link to the NanoVNA I ordered ($49.99), "TYPE 1 - Black color" (and the color makes a difference ...) https://www.amazon.com/gp/product/B07XYRPJML This is a link to the battery, $6.49, 3.7v 450 mAh. I don't know how honest the capacity rating is, but it did com charged https://www.amazon.com/gp/product/B07BTQKK91 Been wondering about that plastic tab on the screen on the upper left... |
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OK package in & things look better It came with a plastic case & every thing looked intact. http://www.skhowell.com/images/DSCN6275.jpg The same terminators seen in the photos were included even though not specifically mentioned in the ad. http://www.skhowell.com/images/DSCN6276.jpg One is clearly a short, one clearly open and the other tested @ 49.8 ohms on my VOM http://www.skhowell.com/images/DSCN6278.jpg Shielding definitely present ... http://www.skhowell.com/images/DSCN6280.jpg and the battery is not. http://www.skhowell.com/images/DSCN6284.jpg I attached a power pack to the USB C receptacle with the provided cord & powered it up. http://www.skhowell.com/images/DSCN6287.jpg Having confirmed it seemed functional, I soldered in the battery I ordered which came in the same delivery. The battery was charged to 4.02 volts at the time of delivery & came with a small plug I cut off. http://www.skhowell.com/images/DSCN6290.jpg No magic smoke got out during the process, so I guess I'm good to go with seeing how this functions. This is a link to the NanoVNA I ordered ($49.99), "TYPE 1 - Black color" (and the color makes a difference ...) https://www.amazon.com/gp/product/B07XYRPJML This is a link to the battery, $6.49, 3.7v 450 mAh. I don't know how honest the capacity rating is, but it did com charged https://www.amazon.com/gp/product/B07BTQKK91 |
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Quoted: That's one of the good ones. I did a quick "case" to cover the sides & maybe provide a bit of protection. The model from Thingiverse was a tad too tight - I had to scale it up 2.5% for a proper fit. I printed in blue PLA+ as that was currently loaded. I may go back & do another when I have the semi-flex TPU loaded. It might provide a bit better shock protection. 
I did have to manually relieve a few areas for better control access and for better USB port access. 
I noted that my firmware did not have some of the options I saw referenced in the groups.io nanoVNA group, so I updated mine to current edy555 build. That was a bit of a struggle getting the proper DFU drivers in place. For a long time I was just seeing the "STM32 Bootloader" in device manager & not "STM Device in DFU Mode" when the unit was connected to the PC. Finally got it connected by uninstalling the the DFuseDemo app and the device instances in Device Manager and taking the "remove driver files" option - that took multiple iterations to get all instances gone. Once everything was cleaned out & no STM32 drivers showing, I did one more install of the DFuseDemo package followed by powering up the unit in DFU mode. That last time worked & I could make the DFuseDemo connection for a firmware upgrade. In retrospect, at the first connection I might have had window report no driver for device & I pointed it to the "drivers" directory within the DFuseDemo install directory. It may just be my machine, but the transfer was very very slow. It worked OK though, the machine started up properly & I went through the touch screen & open/short/load calibrations. In addition to the option to calibrate the touch screen, I now have menu options for TDR operations and a software switch to re-enter DFU mode without having to use a jumper. Along the way, I also installed the STMicroelectronics Virtual COM Port driver software & that is what is used for PC application communications. |
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@aa777888-2
Sure, I was kinda all over the place looking & trying to straighten out the driver thing. Let me get some links & I'll post them. A quick overview, though - groups.io is a good starting point for files & general guides. The process I used was to make use of the DFU mode on the nanoVNA. (there is also a STLinks V2 method that uses hardwire connections instead of the USB - could be a butt saver if a bad upload "bricks" the unit) If the firmware on the unit does not include a "restart in DFU mode" menu item (down under config), you have to force it to boot in that mode by jumping two adjacent through holes on the board edge before turning on the power. I made a little "tweezer" of wire with the ends bent a bit for inserting to short them. A pic (not mine) showing the jumper point I'm talking about https://dw1zws.com/site/wp-content/uploads/2019/09/nano-vna-back-side.jpg. You can remove the jumper as soon as the unit boots. The screen will be all white - thats normal. BTW, an example of a menu including the DFU Mode option (from Hugen's firmware) https://oristopo.github.io/nVhelp/html/Menu.htm With the unit in DFU mode, you can use the USB port to upload the new firmware using a program called DFuseDemo. It is a free piece of software from STMicroelectronics - it used to be $, but they released it for free use. You can get it direct from them, they want a name & email, but they send you a link via email for the actual download. There are other sources, but this is from the original publisher. The link for download is : https://www.st.com/en/development-tools/stsw-stm32080.html The install will also install the DFU file manager. This is the tool that can change .HEX files into .DFU files that are suitable for upload. STMicroelectronics also has a Virtual Com Port driver for the nanoVNA. The download is here: https://www.st.com/content/st_com/en/products/development-tools/software-development-tools/stm32-software-development-tools/stm32-utilities/stsw-stm32102.html My understanding is that this was only needed for versions before Windows 10, but it still worked mine, even if it wasn't needed. You can find firmware versions in both .HEX and .DFU formats in the files section of the Groups.io nanovna-users group. I think the trick to getting the setup running is to not start the nanovna unit in DFU mode until you install the DFuseDemo package & have the drivers available there. The "drivers" directory there is where you want the driver read from. Check with device manager to see what is being used as a driver as you go along. If you start seeing something like "STM32 Bootloader" in the device description you are going to want to uninstall the device & remove the driver files & try loading a driver from the DFuseDemo installed folder. When successful, when the unit is booted in DFU mode you will see something like "STM32 Device in DFU mode" (working from memory here on the labels, it should be similar in either case. This doc (from groups.io) has some screen shots: https://groups.io/g/nanovna-users/files/Firmware/Windows%20guide%20on%20how%20to%20write%20firmware.pdf This might get you started on the right path (I hope). After uploading a new firmware you have to do calibrations. Most new firmware includes calibrating the touch screen. If there, do that first!. Here's a document with an overview of the open/short/load/isol/through calibration : https://groups.io/g/nanovna-users/files/NanoVNA%20Calibration%20Considerations%20and%20Procedure_v1.1.pdf |
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@nikdfish: thanks a ton for the comprehensive reply! I've got the DfuSe software installed, and confirmed that the firmware in my unit is old enough to require the jumper. My biggest misunderstanding was that I did not realize the Windows version had the ability to convert from hex to dfu.
ETA: first pass success on driver installation and firmware upgrade. However, I'm getting some sketchy results, possibly because of issues with hardware revisions. First I tried https://github.com/ttrftech/NanoVNA/releases, but 0.4.0 did not respond to touches of the CONFIG menu item, it would just go back to the main screen. Then I tried the latest from here, https://github.com/hugen79/NanoVNA-H/releases. I've not measured anything yet, but all menus work and it also allowed me to calibrate the screen. There are other choices as well: NanoVNA Firmware Developers on GihHub: Edy555 - https://github.com/ttrftech/NanoVNA Original developer of the NanoVNA Hugen - https://github.com/hugen79/NanoVNA-H Made HW, SW & UI improvements to edy555’s design Erik - https://github.com/erikkaashoek/NanoVNA SW improvements QRP - https://github.com/qrp73/NanoVNA-Q SW & UI improvements Reald - https://github.com/reald/NanoVNA UI improvements What version firmware do you recommend I go with at this time? What are the hardware sensitivities to version? The groups.io group is a dog's breakfast with an SNR that is in the toilet 
Thanks! P.S. when you do an RF calibration that is supposed to be done at the time of the measurement, with all of the cables selected and attached. The idea is that you will be calibrating out everything but the DUT: device under test. So it's not something that's a "once and done" thing when you update the firmware. That said, a "once and done" is fine for uncritical measurements like VSWR. |
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... What version firmware do you recommend I go with at this time? Link? I got the version I used here: https://github.com/ttrftech/NanoVNA/releases It was the file "nanovna-firmware-0.4.0.zip" I may go to a different one, but I wanted something to start with that, at a minimum, would enable DFU mode without a jumper and that added the transform branch to the menu for TDR functions. I'll need to do more research about what looks like it would be the best fit with my hardware & my needs. looks like we were editing at the same time!
That first one you referenced , edy555's current one, really needs the touch screen calibration done first thing or you end up with touches that don't do what you expect. Best I can figure about the hardware thing is that the generic boards (no name associated with their source) are probably pretty close to the edy555 base. Hugen made some changes & the boards are referred to as nanoVNA-H boards. |
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Is this one of "the good ones" ?
https://www.ebay.com/itm/50KHz-900MHz-Vector-Network-Analyzer-Nano-VNA-Kit-MF-HF-VHF-UHF-Antenna-Analyzer/352793898263?hash=item522427ad17:g:87AAAOSwQF5dgY9c |
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I'd buy one of the ones on Amazon (and I did . At least then you've got a much better chance on a return. Worth the $10 premium. Because, let's face it, at this price point, and for what it is, quality is going to vary quite a bit. You could get lucky...or not.
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I'd buy one of the ones on Amazon (and I did . At least then you've got a much better chance on a return. Worth the $10 premium. Because, let's face it, at this price point, and for what it is, quality is going to vary quite a bit. You could get lucky...or not. |
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Quoted: I got one from an eBay seller because there is essentially zero risk of not being able to get $$$ back PROMPTLY if there is an issue. I've tried to return bad Chinese product on eBay. It was a spectacular failure. eBay sucks from a risk standpoint, as both a buyer and seller. |
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Good to hear! I did a quick "case" to cover the sides & maybe provide a bit of protection. The model from Thingiverse was a tad too tight - I had to scale it up 2.5% for a proper fit. I printed in blue PLA+ as that was currently loaded. I may go back & do another when I have the semi-flex TPU loaded. It might provide a bit better shock protection. http://www.skhowell.com/images/DSCN6294.jpg I did have to manually relieve a few areas for better control access and for better USB port access. http://www.skhowell.com/images/DSCN6295.jpg I noted that my firmware did not have some of the options I saw referenced in the groups.io nanoVNA group, so I updated mine to current edy555 build. That was a bit of a struggle getting the proper DFU drivers in place. For a long time I was just seeing the "STM32 Bootloader" in device manager & not "STM Device in DFU Mode" when the unit was connected to the PC. Finally got it connected by uninstalling the the DFuseDemo app and the device instances in Device Manager and taking the "remove driver files" option - that took multiple iterations to get all instances gone. Once everything was cleaned out & no STM32 drivers showing, I did one more install of the DFuseDemo package followed by powering up the unit in DFU mode. That last time worked & I could make the DFuseDemo connection for a firmware upgrade. In retrospect, at the first connection I might have had window report no driver for device & I pointed it to the "drivers" directory within the DFuseDemo install directory. It may just be my machine, but the transfer was very very slow. It worked OK though, the machine started up properly & I went through the touch screen & open/short/load calibrations. In addition to the option to calibrate the touch screen, I now have menu options for TDR operations and a software switch to re-enter DFU mode without having to use a jumper. Along the way, I also installed the STMicroelectronics Virtual COM Port driver software & that is what is used for PC application communications. Quoted:
Quoted: That's one of the good ones. I did a quick "case" to cover the sides & maybe provide a bit of protection. The model from Thingiverse was a tad too tight - I had to scale it up 2.5% for a proper fit. I printed in blue PLA+ as that was currently loaded. I may go back & do another when I have the semi-flex TPU loaded. It might provide a bit better shock protection. http://www.skhowell.com/images/DSCN6294.jpg I did have to manually relieve a few areas for better control access and for better USB port access. http://www.skhowell.com/images/DSCN6295.jpg I noted that my firmware did not have some of the options I saw referenced in the groups.io nanoVNA group, so I updated mine to current edy555 build. That was a bit of a struggle getting the proper DFU drivers in place. For a long time I was just seeing the "STM32 Bootloader" in device manager & not "STM Device in DFU Mode" when the unit was connected to the PC. Finally got it connected by uninstalling the the DFuseDemo app and the device instances in Device Manager and taking the "remove driver files" option - that took multiple iterations to get all instances gone. Once everything was cleaned out & no STM32 drivers showing, I did one more install of the DFuseDemo package followed by powering up the unit in DFU mode. That last time worked & I could make the DFuseDemo connection for a firmware upgrade. In retrospect, at the first connection I might have had window report no driver for device & I pointed it to the "drivers" directory within the DFuseDemo install directory. It may just be my machine, but the transfer was very very slow. It worked OK though, the machine started up properly & I went through the touch screen & open/short/load calibrations. In addition to the option to calibrate the touch screen, I now have menu options for TDR operations and a software switch to re-enter DFU mode without having to use a jumper. Along the way, I also installed the STMicroelectronics Virtual COM Port driver software & that is what is used for PC application communications. That case, although not mentioned anywhere , is designed to be held together by the back screw plate and front screw plate of the nanoVNA. So you unscrew both plates fit the back and tip case halves then screw the plates back on and those screwed on plates hold the case together That might be why you needed to make the case 2.5% larger if you did not know that. It took me a while to figure it out since the comments dont mention that at all. ETA: actually it is not the same case. The case I printed has a small door with storage area for a pen and the calibration terminations . |
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Quoted:based on the pic it looks like you printed the same case I did.
That case, although not mentioned anywhere , is designed to be held together by the back screw plate and front screw plate of the nanoVNA. So you unscrew both plates fit the back and tip case halves then screw the plates back on and those screwed on plates hold the case together That might be why you needed to make the case 2.5% larger if you did not know that. It took me a while to figure it out since the comments dont mention that at all. ETA: actually it is not the same case. The case I printed has a small door with storage area for a pen and the calibration terminations . There are so many Chinese vendors making these things that there is bound to be a wide variation in PCB tolerances and dimensions. |
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I did the resize to accommodate the size of the metal cover plates. That was the major sticking point on the first print.
This is printing now. A slide cover box with two levels (via an inside cover). VNA goes in the bottom middle, adapters/calibration pieces in the side pocket & cables above the inner cover. 
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Please explain how you are safer buying from a Chinese vendor on eBay than on Amazon? I've tried to return bad Chinese product on eBay. It was a spectacular failure. eBay sucks from a risk standpoint, as both a buyer and seller. The Chinese will use every trick in the book to confuse, delay and screw the customer and I enjoy ----when it's fair and justified, defeating them, and have always been successful, because I became informed re: eBay policies and am highly motivated and determined to prevail. eBay is fantastic about protecting the Buyer and their Customer service is a [usually] fast phone call away. In the case of a foreign seller, they are required to send a Return Label ---OR provide the return shipping amount UP FRONT! In the case of Chinese Sellers, USPO and other carriers are expensive to ship items back WITH TRACKING. For example, a pair of shoes that a Chinese Seller sells for $100 and pays maybe $20 for would cost approx. $65 to send back to China with tracking. It's not economically viable for the Chinese Seller to do that, so they will -ultimately- let you keep the item. Most folks don't understand this particular eBay policy, but I'm here to tell you I have resolved probably 35 Chinese returns this way over the past 10 years. As far as domestic Sellers, if there is an issue it's taken care of FAST! I purchase a lot of electronic test and high vacuum equipment [most of my general shopping is on eBay as well], and 2 weeks ago a Seller stupidly packed some heavy vacuum system items with little padding, and they were damaged, to my disappointment. Brand new stuff for pennies on the dollar. I clicked on the "Return item" button, explained the situation, the components were ruined and the Seller understood, and instead of paying a lot of money to ship the heavy box back, said keep and recycle them. Sometimes the Seller wants photos and they are easily linked. I don't deal with Amazon in part because of communication difficulties, higher prices, not able to negotiate, etc. eBay is fantastic considering their protection and resolution of issues, and the wide variety of new and used items and the often excellent prices. If there had been an issue with my network analyzer from the Seller I used, I'd have had a refund in a couple days. |
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You definitely CAN get phucked on fleabay! Buy something with PP and have it drawn from your checking acct. Ask me how I know.  |