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Re: RF Active Probe
That probe might be useful for use with the spectrum analyzer to provide a means to probe some high-z circuits without loading them down with the 50 ohms presented by the SA input, but I think it would be fairly useless with the VNA.
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Ray WB6TPU On Aug 17, 2021, at 7:58 PM, avvidclif <clif@...> wrote: |
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Re: SMA connector pulled off of cable.
Those are unobtanium around these parts so I have to
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get what's available at Ali, Ebay etc. Anyway I prefer PTFE coax and soldered connectors. RG316DS would be best (for me) but can't find non fake ones ... On Wed, 18 Aug 2021 at 04:02, Clyde Spencer <cftr01b@...> wrote:
OK lets run this off the cliff. If you have a propensity to build your own |
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Re: SMA connector pulled off of cable.
OK lets run this off the cliff. If you have a propensity to build your own
cables I would suggest LMR195 ultraflex cable. This is the same size and very similar characteristics as RG142but is much more flexible. LMR-195 ultraflex is a 100% shielded cable.There are a variety of crimp connectors for LMR195 ultraflex and somewhat reasonable prices. Using cables from this LMR195 ultraflex are more robust than those made with the RG316 cable and provide less loss perfoot. *Clyde K. Spencer* On Tue, Aug 17, 2021 at 9:54 PM Dragan Milivojevic <d.milivojevic@...> wrote: Get some semi rigid cables, the shield is soldered to the connector |
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Re: SMA connector pulled off of cable.
Get some semi rigid cables, the shield is soldered to the connector
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shell so it won't come off any time soon. RG402 is the thicker and stiffer variant, RG405 is the thinner, more flexible one. I got these (and some other M-M, M-F variants): Avoid RG316, I bought a number of those on AliExpress and all were fake (non PTFE insulator). They can't use regular plastic as dielectric on semi rigid ones, since the shield has to be dipped in solder, so all semi rigid cables use real PTFE. The linked store also has real RG142, but those are quite springy so not as convenient to use. On Wed, 18 Aug 2021 at 02:52, Bill Klymus W5PB <bktx75@...> wrote:
This past weekend, I accidentally pulled the SMA connector off one of the |
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Re: SMA connector pulled off of cable.
VNA cables need to be considered as consumables, they will eventually break or the connectors become worn. There are many sources of flexible cables online, Amazon and EBay have many. There is nothing magic about the ones that come with the nanoVNA, they are just run of the mill stuff. I always mark mine so that I can return them to the orientation and port they were on when I did a calibration.
73, Don N2VGU |
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Re: SMA connector pulled off of cable.
Save the broken cable. Maybe you can use it when building a test fixture or
similar. *Clyde K. Spencer* On Tue, Aug 17, 2021 at 9:16 PM Clyde Spencer via groups.io <cftr01b= [email protected]> wrote: I would no longer trust that cable. You can get a pair of these cables from |
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Re: SMA connector pulled off of cable.
I would no longer trust that cable. You can get a pair of these cables from
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Amazon.com or other sources. The screen shot below is from Amazon.com [image: image.png] *Clyde K. Spencer* On Tue, Aug 17, 2021 at 8:52 PM Bill Klymus W5PB <bktx75@...> wrote:
This past weekend, I accidentally pulled the SMA connector off one of the |
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SMA connector pulled off of cable.
This past weekend, I accidentally pulled the SMA connector off one of the thin coaxial cables. The outer threaded portion came off, but the center pinwas still attached. The cable checks out, or at least seems to. Should I be wary of it's reliability? And if so, what is a good replacement source. I worry about these cables, being slightly stiff, that they can only take so much bending before they will fail, anyway.
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Re: danger measuring antenna
Yes, it was also something for the final DC block from the 6146 plate
voltage to work against. Dave - W?LEV On Tue, Aug 17, 2021 at 11:40 PM Brian D < g3vgz-groups.io@...> wrote: "David Eckhardt" <davearea51a@...> wrote:--Ilarge-valued *Dave - W?LEV* *Just Let Darwin Work* |
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Re: danger measuring antenna
"David Eckhardt" <davearea51a@...> wrote:
IManly to prevent dangerous voltages on the feedline due to breakdown in the plate capacitor leaking HT onto the feedline, essential on high power valve PAs. -- Brian D G3VGZ G8AOE G3T IO94im |
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Re: help with driver issue for a newbie
Hi Vladimir, Larry, and Group:
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Thanks so much for your advice. The references that you sent basically go in the direction of using the Cypress driver. I tried this, but to no avail - also get similar symptoms as with the STM driver. Given that I get the yellow warning triangle when I install the driver, i.e. before the VNA is connected, my guess is that the problem is at the Windows level, rather than at the nanoVNA level. Has anyone else experienced (and overcome) this problem? Regards, Ray 4X1RB From the home of Prof. Emeritus Raymond (Reuven) Boxman School of Electrical Engineering Tel Aviv University Cell: ???? +972 544 634 217 CEO Clear Wave Ltd.? ????????????? Scientific Writing Courses: ??????? -----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Vladimir Lebedev Sent: ????? 16 ?????? 2021 21:45 To: [email protected] Subject: Re: [nanovna-users] help with driver issue for a newbie Hello Ray! Please try here: Driver and software : without driver works Your nanoVNA V2 not! Also, first driver, second software and fw update Here is user manual Best regards Vladimir, dl7pga |
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Mosley traps measurements question
I wondered if anyone has measured Mosley traps with the NanoVNA? I have one on order.
Currently I used a MFJ259c to try to get some results. I took the trap apart and put a 50 pica farad in series to measure a frequency but cannot measure the trap inside the tube. It has two parallel traps in a typical Mosley trap. The cap was used to at least measure the inductors. Goal is to measure the Mosley trap frequency of each trap. |
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Re: help with driver issue for a newbie
Dear Vladimir,
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Thank you for your suggestion. I will look into it today. 73 Ray 4X1RB From the home of Prof. Emeritus Raymond (Reuven) Boxman School of Electrical Engineering Tel Aviv University Cell: ???? +972 544 634 217 CEO Clear Wave Ltd.? ????????????? Scientific Writing Courses: ??????? -----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Vladimir Lebedev Sent: ????? 16 ?????? 2021 21:45 To: [email protected] Subject: Re: [nanovna-users] help with driver issue for a newbie Hello Ray! Please try here: Driver and software : without driver works Your nanoVNA V2 not! Also, first driver, second software and fw update Here is user manual Best regards Vladimir, dl7pga |
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Re: Download NanaoVNA Labview
On Wed, Dec 11, 2019 at 03:19 AM, <nanovnauser@...> wrote:
I have a lot of respect for the gentleman in question. He must be independently wealthy as he seemingly tests every multimeter in existence and then posts the results of his testing for FREE. I have never asked any questions of him, but he seems very courteous and knowledgeable and giving in his replies he posts. Hopefully, disparagement will get you nowhere! It is his to do with what he wants. Perchance remarks like yours dissuades him - why deal with people who ......... Larry |
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Re: help with driver issue for a newbie
Thanks for the suggestion! I will investigate it later today....
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Ray From the home of Prof. Emeritus Raymond (Reuven) Boxman School of Electrical Engineering Tel Aviv University Cell: ???? +972 544 634 217 CEO Clear Wave Ltd.? ????????????? Scientific Writing Courses: ??????? -----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Larry Rothman Sent: ????? 16 ?????? 2021 20:47 To: [email protected] Subject: Re: [nanovna-users] help with driver issue for a newbie Have you looked over in either of the nanovna-V2 forums? I just found this thread there: /g/NanoVNA-V2/topic/win_10_issue/77411380?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,80,77411380 On Monday, August 16, 2021, 12:40:41 p.m. EDT, Ray <boxman@...> wrote: Hi All, I am having a frustrating driver issue. It is all the more frustrating because at some point I succeeded in controlling my nanoVNA from various software packages from my laptop, and was all set to study the various options, choose the one most suitable for me, and get to work! But currently, the computer and the nanoVNA do not appear to talk with each other. I have no idea of which nanoVNA v. 2 variant I have, but please see the attached photo. Under version, it states that the hardware was designed by OwoComm. I purchase it from Ali Express for $62.? I am trying to connect with a relatively recent Lenovo laptop running Windows 10 pro. It just did an update to version 20H2 (today) but I had the same problem before and after the update. I have the following symptoms: 1.? ? ? When I plug in the USB cable, the nanoVNA screen remains active. 2.? ? ? When I plug in or disconnect the USB cable, I get a characteristic dong from the laptop, but I do not observe any difference in the device manager display. 3.? ? ? What appears in the device manager display under ports is "STMicroelectronics Virtual COM port (COM4)" together with the yellow triangular warning icon, whether the nanoVNA is connected regularly, or in DFU mode, or disconnected (see attached screen shot). 4.? ? ? If I right click on this and look at properties, I get a.? ? ? (general), "The device cannot start (Code 10). The specified request is not a valid operation for the target device b.? ? ? (driver): driver version 1.4.0.0, driver date 2-Aug-13 c.? ? ? (Events): information: Device ROOT\PORTS\0000 requires further installation I followed the procedure in Absolute Beginner's Guide to NanoVNA by Martin Svaco, 9A2JK, and in particular tried all of the methods suggested in the TROUBLESHOOTING THE DRIVER INSTALLATION section. Before today's update, I also used CCleaner to clean-up the registry. But all to no avail. I tried updating, uninstalling, reinstalling, the driver etc., but nothing alleviated the above described symptoms. I would value any and all advice! 73, Ray 4X1RB From the home of Prof. Emeritus Raymond (Reuven) Boxman School of Electrical Engineering Tel Aviv University Cell:? ? ? +972 544 634 217 CEO Clear Wave Ltd.? ? ? ? ? ? ? ? <> Scientific Writing Courses:? ? ? ? <> |
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Re: Where does this noise/instability come from at and around 300MHz?
Just wondering if you hit the parts you're testing with a heat gun and/or freezing spray to see how how well the consumer level parts react.
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On Tuesday, August 17, 2021, 05:36:40 a.m. EDT, OneOfEleven <cmoss296@...> wrote:
On Wed, Jun 30, 2021 at 11:31 AM, DiSlord wrote: I've been using the Si5351 in another project and decided to test the chip at boot-up to find each individual chips (Si5351) possible PLL frequency range rather than having the 300MHz parameter be user settable. All I do is to do a quick boot-up sweep of each PLL (A and B) in the chip to find their min and max frequencies by monitoring the PLL lock bit in the chip. Each PLL typical takes around 600us to lock to a desired frequency, so if it takes longer than say 1ms to lock then I take that as being the PLL's min and max limits. I'm finding the PLL's usable frequency range (specified as 600MHz to 900MHz) in each can vary by quite a bit, so auto finding the real limits is very useful and handy. Rather than storing the min/max PLL limits for each of the two PLL's I use the same min/max limits for both PLL's - a range that reliably works for BOTH PLL's (ie, I use the worse case min/max scanned frequency range from the two PLL's). Doing this in the NanoVNA's when the user turns the device on would remove the guess work, chip variation, temperature PLL lock range dependency and the user command etc from the equation. Each individual unit would auto self select the 300MHz switch point. Could still keep a manual settings if desired I guess. |
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Re: V2 SD card firmware
DiSlord,
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For the V2 Plus units with no RTC, can the SDcard filenames be read and the next file saved has its last character incremented by one? This assumes a fully numeric filename so there are no illegal ascii chars used. Keep it simple so that on a unit with no RTC, all screen dumps and S files stored would be start with a filename of "00001" and be incremented from there. That would solve the issue on the V2 devices and should only be active on those devices. ...Larry On Tuesday, August 17, 2021, 02:35:38 a.m. EDT, DiSlord <dislordlive@...> wrote:
Yes, old files will overwriting by new |
Donald S Brant Jr
Roger Need
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