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Re: CMC MEASUREMENTS - PDF'ed & SIZE REDUCED
Are you referring to PVC here?
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73, and thanks, Dave (NK7Z) ARRL Volunteer Examiner ARRL Technical Specialist, RFI ARRL Asst. Director, NW Division, Technical Resources On 2/8/21 8:39 AM, Jim Lux wrote:
It's also fairly hygroscopic, but I doubt moisture content drives the dissipation. |
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Re: CMC MEASUREMENTS - PDF'ed & SIZE REDUCED
On 2/8/21 8:04 AM, Gary Rondeau wrote:
Very nice compilation!PVC has a low melting/softening point, so it's sensitive to these kinds of effects. It's also fairly hygroscopic, but I doubt moisture content drives the dissipation. Skin depth is a thing, too. And since it's proportional to 1/sqrt(mu), higher mu makes the skin depth smaller. Fortunately it's proportional to sqrt(resistivity), and the resisitivity of ferrites is very high Any comments? |
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Re: upgrading firmware?
Great!
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...Larry On Monday, February 8, 2021, 11:23:17 a.m. EST, Jamie WW3S <ww3s@...> wrote:
Sucess !!! Thanks Larry, I downloaded 1.0.45, and followed the same steps I did before and it loaded fine with the original DFU app....somehow the 1.0.39 must have been kludged somewhere.... ------ Original Message ------ From: "Larry Rothman" <nlroth@...> To: "[email protected]" <[email protected]> Sent: 2/8/2021 8:17:23 AM Subject: Re: [nanovna-users] upgrading firmware? ? Jamie, |
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Re: upgrading firmware?
Sucess !!!
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Thanks Larry, I downloaded 1.0.45, and followed the same steps I did before and it loaded fine with the original DFU app....somehow the 1.0.39 must have been kludged somewhere.... ------ Original Message ------
From: "Larry Rothman" <nlroth@...> To: "[email protected]" <[email protected]> Sent: 2/8/2021 8:17:23 AM Subject: Re: [nanovna-users] upgrading firmware? Jamie, |
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Re: CMC MEASUREMENTS - PDF'ed & SIZE REDUCED
Gary Rondeau
Very nice compilation!
So what is up with the PVC insulation? I know that PVC is particularly bad in terms of dissipation factor - but is it insulation self heating or just getting melted by a hot ferrite core? I ask because I made a few measurements with a thermal probe on the side of a single core FT-240-31 with 8T RG-11 that is a choke I have for my 10m antenna. What I discovered is the the temperature rises very quickly on the core surface when you turn on the power and then more slowly diffuses into the center of the core. Similarly, when the power is shut off, the temperature falls relatively quickly on the surface, as the surface heat conducts inward or is lost to convection with the air. I can imagine that extreme non-uniform heating could lead to fracturing of the brittle core material. Any comments? Gary AF7NX |
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Re: upgrading firmware?
Many thanks for the link to that document... I just ordered a NanoVNA, and am getting ready for it.
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73, and thanks, Dave (NK7Z) ARRL Volunteer Examiner ARRL Technical Specialist, RFI ARRL Asst. Director, NW Division, Technical Resources On 2/8/21 12:01 AM, Martin J.K. wrote:
See Absolute_Beginner_Guide_NanoVNA_v1_6.pdf, page 49. |
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Re: PROCEDURES for MEASURING DM LOSS and CM ATTENUATION of CMCs
On Sun, Feb 7, 2021 at 05:04 PM, David Eckhardt wrote:
For a different perspective, G3TXQ's Common-mode Choke webpage discusses why reactive (e.g. inductive) common-mode chokes are undesirable, and he gives an example of an inductive common-mode choke actually worsening a feedline's common-mode current. - Jeff, k6jca |
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Re: upgrading firmware?
Jamie,
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I think you've overwritten the existing copy with a dump from your device. Delete the firmware you're trying to update with and get a new copy from the files section of the forum - use 1.0.45 ...Larry On Monday, February 8, 2021, 7:53:04 a.m. EST, Jamie WW3S <ww3s@...> wrote:
Yea, tried that, no joy....followed the W2AEW YouTube video ( mine is exactly like his), works great, until I restart, still says 0.5.0.....I¡¯m going to try Larry¡¯s modified GUI next....thanks...l On Feb 8, 2021, at 3:01 AM, Martin J.K. <martin.svaco@...> wrote: |
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Re: upgrading firmware?
Yea, tried that, no joy....followed the W2AEW YouTube video ( mine is exactly like his), works great, until I restart, still says 0.5.0.....I¡¯m going to try Larry¡¯s modified GUI next....thanks...l
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On Feb 8, 2021, at 3:01 AM, Martin J.K. <martin.svaco@...> wrote: |
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Re: upgrading firmware?
Jamie,
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It's in the Misc folder: /g/nanovna-users/files/Miscellaneous Rename the original defuse.exe to defuse.orig.exe and then drop in the modified one - there are two: One with original font and one with bold font - use one and rename it to defuse.exe ...Larry On Sunday, February 7, 2021, 6:21:30 p.m. EST, Jamie WW3S <ww3s@...> wrote:
Larry, what folder should I look in? I see a couple files from you but am missing a modified EXE file.... On Feb 7, 2021, at 4:17 PM, Larry Rothman <nlroth@...> wrote: |
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Re: PROCEDURES for MEASURING DM LOSS and CM ATTENUATION of CMCs
Ed, unfortunately I did not measure that parameter. Most of the readers
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are just interested in dB attenuation so I didn't measure the complex impedance. However, the inductance of the CMC is responsible for the CM attenuation. Core losses and conductor resistive losses are minimal. So, most of the CM attenuation is due to the inductance of each bifilar winding. It's the bifilar winding that forces through magnetics in the core, good DM match on the balanced side of each CMC. Dave - W?LEV On Mon, Feb 8, 2021 at 12:58 AM AG6CX <edwmccann@...> wrote:
Great work Dave. --
*Dave - W?LEV* *Just Let Darwin Work* |
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Re: upgrading firmware?
Larry, what folder should I look in? I see a couple files from you but am missing a modified EXE file....
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On Feb 7, 2021, at 4:17 PM, Larry Rothman <nlroth@...> wrote: |
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CMC MEASUREMENTS - PDF'ed & SIZE REDUCED
On encouragement from a few posters, I have updated my construction and
measurements of quite a number of CMCs. My hope and goal in all this is to encourage others to construct something simple which can greatly reduce coupling of local RFI into the receive path of their amateur stations and keep the feedline from radiating from their antennas. I'd also encourage the group to build and use their NANOs. Hopefully this and the procedures I previously posted will accomplish some small amount of home brewing and satisfaction of having done it all yourself - with good measurements thanks to the folks who made the NANOs possible. Please have a look at the attachment. Dave - W?LEV |
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Re: upgrading firmware?
You saved the device few to the same name as the new fw... you've overwritten it.?
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Read the wiki about defuse and grab my modified exe.in the files section with better naming of commands.? Also, grab a new copy of fw out.of the archives and delete you prev one Sent from Rogers Yahoo Mail on Android On Sun., 7 Feb. 2021 at 3:43 p.m., Jamie WW3S<ww3s@...> wrote: I did do the verify, it says its loaded.....but whn I go to config, to the splash screen, it says 0.5.0.....is that display a hardware or firmware version? ------ Original Message ------
From: "DiSlord" <dislordlive@...> To: [email protected] Sent: 2/7/2021 3:36:39 PM Subject: Re: [nanovna-users] upgrading firmware? I think you use Upload Action button (this mean read firmware from device and store to selected file), check file size - should be 128k |
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Re: upgrading firmware?
I did do the verify, it says its loaded.....but whn I go to config, to the splash screen, it says 0.5.0.....is that display a hardware or firmware version?
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------ Original Message ------
From: "DiSlord" <dislordlive@...> To: [email protected] Sent: 2/7/2021 3:36:39 PM Subject: Re: [nanovna-users] upgrading firmware? I think you use Upload Action button (this mean read firmware from device and store to selected file), check file size - should be 128k |
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Re: upgrading firmware?
I think you use Upload Action button (this mean read firmware from device and store to selected file), check file size - should be 128k
Need use Upgrade oe Verify Action buttons, select choose... and select firmware (unpack again it from archive, i think you rewrite it by downloading from device). After use Upgrade button. |
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upgrading firmware?
I have a NanoVNA-H4, edy555 design, it says I have version 0.5.0 Feb 21-2020. I downloaded v1.0.39.rar, extracted it using 7 zip, am running the DfuSE demo softwate, I place the unit in DFU mode by pressing the multiswtich down while turning on. the software recognizes the device, I chose the extracted dfu file from the Upload Verify section. I chose upgrade.....it erases, then uploads, but when I restart the nano, its still version 0.5.0....what am I doing wrong?
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Re: How to find the right ferrite toroid for a receiving antenna balun?
On Mon, Jan 13, 2020 at 06:06 AM, <ptapon@...> wrote:
This is pretty late in the game, but it also depends on your receiver. Ham radio equipment is (usually) designed for 50 ohms, but SWL type radios typically had higher impedance antenna inputs. Are you sure you really need a transformer (you're describing a transformer, not a balun - as has already been mentioned). -- Doug, K8RFT |
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