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How to make nanoVNA "bulletproof" ?

Anne Ranch #28364 Little over statement in the title , but ... Again - started using the nanoVNA , to tune antenna, about two weeks ago and 1. it is HOT in Huston and impossible to read the display in direct sun 2. after "transmission line theory " is dutifully applied - the "portable " miniature analyzer looses its both advantages as "miniature " and "portable". 3. it is better to keep USB connected and keep battery alive 4. after I get nanoVNA-saver to behave I won't need the display anyway 5. in future I may add "calibration switch".... actually it is of great disadvantage hanging on USB cable and on pretty stiff end of RG6 ( that what I have to work with ...) I do not want fancy "enclosure " and I an not stupid to break the SMA connectors - I need to nail the nanoVNA to the top of my desk ! ...more overstatement ... Seriously - I have what used to be antenna rotator aluminum plate , about 1/4 inch thick I can cut to size of nanoVNA , add some " rubber feet" ... Would that work ? Open to ideas ... no Altoids boxes , please...
Clyde Lambert All Messages By This Member #28372 There is always Velcro. I use sticky back Velcro to attach devices to a serface. That way if I want to move it to somewhere else, I just separate it and move on. Clyde KC7BJE
Martin Glazer All Messages By This Member #28377 For the professional VNA analysers, Do they put atorroid chokes on those? I was wondering. Martin N6QlH On Wed, Jun 8, 2022 at 7:08 PM Clyde Lambert <clyde.lambert@...> wrote: There is always Velcro. I use sticky back Velcro to attach devices to a serface. That way if I want to move it to somewhere else, I just separate it and move on. Clyde KC7BJE
Jim Lux All Messages By This Member #28380 On 6/8/22 9:58 PM, Martin Glazer wrote: For the professional VNA analysers, Do they put atorroid chokes on those? I was wondering. That would depend on the test setup.? Most people, when measuring an antenna, use chokes and/or baluns at various points. In a anechoic chamber situation, like when doing a near field scan (which uses a VNA as the measurement instrument) you'd make sure the feed lines are not coupled to the antenna, and chokes are a typical way to do that. In the field, with something like a Keysight Fieldfox, it kind of depends. If I'm measuring a dish antenna and its feedlines, I might not use any choke at the VNA - the feedline is sufficiently decoupled.? Measuring something like a dipole, you bet I'd use a bunch of toroids and clamp on ferrites. What you typically do is make the measurement without, then add some and see if it changes. If it changed, then try adding some more and see if it changes again. In extreme cases, one goes to remote or programmed operation and putting the test equipment in a box with a small computer to drive it. Right now, I'm trying to figure out how to measure the 4 port impedance of a pair of deployable dipoles, and shoehorn everything into a metal box that represents the structure to which the dipole is attached.
Donald S Brant Jr All Messages By This Member #28381 I have been using VNAs at work since the '80s. Professional "box" VNAs have extensive internal power supply and data line decoupling/shielding and are designed as a system with their PC/controllers/display, all housed in a heavy metal EMI-shielded enclosure where all ingresses are carefully filtered, with a chassis grounded via power cord. The pro USB-based VNAs (Copper Mountain make outstanding units) usually come in a stout shielded housing and generally have a ferrite (or one on each end) molded into the provided heavy and presumably well-shielded USB cable and the user is cautioned to use that cable only. Quite a different situation from an inexpensive handheld device which communicates with and is powered by a skinny $1cable that doubles as a dandy RF pickup antenna going into a random poorly-grounded or ungrounded laptop or charger with unknown USB power quality. So it is not unreasonable to expect to have to do some RF decoupling work when using these amazing little instruments, especially when measuring antennas. They may have their issues but just step back and think of what your $50 or $100 buys; they can do 95% of the work that the multi-$100K Keysight ones do. 73, Don N2VGU
K8HTB All Messages By This Member #28382 I cut a piece of 1/4 inch plexiglass about 9 inches x 6 put Velcro on the nanovna and cables . It keeps the cables from damaging the connectors. De K8HTB
Anne Ranch #28383 Excellent idea - combine "rotator plate" ( for stability ) with superglue and Velcro ! I actually was not looking to buy those tiny screws to permanently mount the device onto the plate ... Vaclav AA7EJ
Peter Hall, VK6HP/VK6MJM All Messages By This Member #28385 Anne, I realize this is a bit different to the approach you're thinking about but maybe it's of some interest. I "re-packaged" my nanoVNA-F to address some of the issues you mention, and to provide some "saver" connectors. Although the nanoVNA is essentially a disposable item I decided to give it the best chance possible at a long and consistent measurement life; I've attached a picture to show the general idea. The plastic instrument box is spare from another project and I hinged the lid using hardware store small cabinet hinges. The VNA is mounted using velcro and the bulkhead adapters and patch leads came from the junk box or eBay. I often use the unit in the field with a laptop, most recently for some LF/MF antenna work. Although probably unnecessary in the portable setup I did, as a matter of practice, include a small toroid choke (type 77 material) for the USB lead. Finally, I couldn't function without a decent stylus when using the VNA stand-alone. All of my external systems under test have PL259 or SMA connectors, hence the choice of bulkhead adapters. Best regards, Peter. VNA_sm.jpg
Siegfried Jackstien All Messages By This Member #28386 Add sma to n adaptors...can or better should be with flange (others with big nut may work also) ... Screw flange on a sheet metal angled 90 degrees to form end and base plate... And then use thicker cables with n connectors like i also use on my saa2n .... Ok you then need new calibration set with n connectors.. But that all will be more robust as using those flimsy sma.. If you stay on sma then i recommend to use sma extender (male female adaptor).... So if worn out you can replace that extender Both will make it more robust... Either n sockets.... Or sma extender... So if worn out... Easy to replace I prefer n socket in most cases... But i have both cause i own an saa2n and a v2plus4... Both with modded fw from dislord :-) Dg9bfc sigi Am 09.06.2022 15:30 schrieb Anne Ranch <anneranch2442@...>: toggle quoted message Show quoted text Excellent idea - combine "rotator plate" ( for stability ) with superglue and Velcro ! I actually was not looking to? buy those tiny screws to permanently mount the device onto the plate ... Vaclav AA7EJ
Siegfried Jackstien All Messages By This Member #28387 Nice job.... But i would bot use pl sockets but n sockets cause with v2 plus4 or saa2n i measure also on 13cm... Even at 70cm the n socket is better as pl... Your case is so big it should be easy to add a bigger sized battery... Grin Greetz Dg9bfc sigi Am 09.06.2022 16:54 schrieb Siegfried.Jackstien@...: toggle quoted message Show quoted text Add sma to n adaptors...can or better should be with flange (others with big nut may work also) ... Screw flange on a sheet metal angled 90 degrees to form end and base plate... And then use thicker cables with n connectors like i also use on my saa2n .... Ok you then need new calibration set with n connectors.. But that all will be more robust as using those flimsy sma.. If you stay on sma then i recommend to use sma extender (male female adaptor).... So if worn out you can replace that extender Both will make it more robust... Either n sockets.... Or sma extender... So if worn out... Easy to replace I prefer n socket in most cases... But i have both cause i own an saa2n and a v2plus4... Both with modded fw from dislord :-) Dg9bfc sigi Am 09.06.2022 15:30 schrieb Anne Ranch <anneranch2442@...>: Excellent idea - combine "rotator plate" ( for stability ) with superglue and Velcro ! I actually was not looking to? buy those tiny screws to permanently mount the device onto the plate ... Vaclav AA7EJ -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#28383): /g/nanovna-users/message/28383 Mute This Topic: /mt/91635960/146118 -=-=- Learn about the NanoVNA in the following forum areas: Documentation & Update Files: /g/nanovna-users/files Knowledge-based Wiki: /g/nanovna-users/wiki -=-=- Group Owner: [email protected] Unsubscribe: /g/nanovna-users/leave/11170209/146118/345100570/xyzzy [siegfried.jackstien@...] -=-=-=-=-=-=-=-=-=-=-=-
Doug #28389 A photo please. Doug toggle quoted message Show quoted text On 09/06/2022 09:26, K8HTB wrote: I cut a piece of 1/4 inch plexiglass about 9 inches x 6 put Velcro on the nanovna and cables . It keeps the cables from damaging the connectors. De K8HTB -- /If you forward this email, please delete the forwarding history which also includes my email address. When sending emails, please BCC so as to hide all addresses. Thanks for helping to prevent Scammers and Spammers from mining addresses and spreading viruses./ Doug Kearney Ottawa, ON -- This email has been checked for viruses by Avast antivirus software.
Peter Hall, VK6HP/VK6MJM All Messages By This Member #28390 Sigi, My cupboard yielded exactly 1 suitable box but, in the event, having a bigger format gets away from the "little and fiddly" form of the nano, as well as accommodating the nice R&S flex patch cables I found. Yes, by all means select the bulkhead adapters according to need. With a bit of Dremel work I think I could have included a third set of connectors but there was no need in my application. Doug: re pictures: I see a thumbnail with my first post. Click for a larger image. 73, Peter.

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