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Re: how good is a rain gutter antenna
With the maximum SWR ¡À 2.5 : 1, you must have a lot of loss in the system.
Likely due to that crazy 9:1 transformer. You have a NANOVNA, so measure the through loss of that transformer. I'd suggest just feeding your gutter directly without the transformer with a counterpoise. Lay a wire on the soil surface of a good length as a counterpoise instead of a ground rod. Then let a capable manual antenna matching network correct the SWR to keep the transmitter "happy". I was once in your situation having to use a downspout as an antenna in a large apartment complex at the east side of Loveland, Colorado. Yes, the RFI was something to behold!! We were on the third floor, the top-most floor, and I ran coax out to the downspout with an ugly balun at the feedpoint. I used the small patio railing (scraped the paint off one of the mounting legs for contact) as a very small counterpoise. I had a manual matching network inside to correct the SWR. It sort'a worked, but the RFI was unbelievably horrendous! One early morning I decided to try 75-meters. OK, I matched the end of the feedline with the matching network at 10-watts. I slowly increased the power to the system. When I reached 25-watts, the fire alarm for the entire complex (about two city blocks) tripped. Needless to mention, everyone hit the parking lot with no fire present. Be careful what you do in any apartment complex. ????? Would I do it again? Absolutely!! Lunch and supper times were especially "interesting" at and around 2.45 GHz on the spectrum analyzer. All the microwave ovens became active. Don't think for a picosecond those ovens don't leak! With the broadband horn antenna, I could pick out nearly every one, even from several blocks away. Dave - W?LEV On Tue, Mar 4, 2025 at 2:55?PM Barry K3EUI via groups.io <k3euibarry= [email protected]> wrote: -- *Dave - W?LEV* -- Dave - W?LEV |
how good is a rain gutter antenna
*? ?? RAIN? GUTTER? ANTENNA?? on upper HF bands*
* * *I've been experimenting with a variety of HF antennas here at my new QTH at Crosslands Retirement Community in Kennett Square, PA. * *I have some space limitations, but live on the first floor of a two-story apartment building.* *Lots of RFI from everywhere inside the building? - S9 on 80m and 40m, less noise on 20 and 10m. * * * *I have a? 140 ft end-fed wire with a 49:1 UNUN which tunes up easily on 80/40/20m? and not so well on 17m/15m/10m.* *This end-fed is horizontal, low to the ground (winds among trees) and is good for high-angle NVIS radiation on 80/40m.* *I use it on the PA NBEMS net (3583 kHz) and on the Mid-Atlantic NBEMS net (7068 kHz) * * * * * *I'd like to get up something with a _low-angle_ signal for DX on? 20/17/10m bands. * *But can I keep any HF antenna "hidden"?* * * *What I am now trying is the aluminum _rain gutter_? for our building, vertical for about 20 ft, makes a right angle turn and runs horizontally for about 20 ft.* *The coax attaches at the base of the gutter, near ground, to a 9:1 UNUN with a sheet metal screw into the gutter for a decent electrical connection. * * * *So overall, about 40 ft of thick (painted) aluminum gutter radiating element - in the shape of an inverted? L and? not resonant on any ham band.* *Lowest SWR around? 16 MHz.? It looks like it might work out on the 30m band as well (10.1 MHz). * *I have a Palomar Engineering? (500W rating) 9:1? UNUN on? 50 ft RG8X? coax into the shack (closet).* *I have one counterpoise wire about 20 ft long attached to the UNUN?? ground terminal.* *Then a good manual tuner in the shack to an HF rig for very low SWR on any band. * * * *Here is what I see on my Nano VNA from 10 - 30 MHz: ? not bad SWR? (under 2.5:1) ? in the shack on 20/17/15/10 meters.* *I'll give it a try over the next few weeks and see if the local noise is more/less on these bands, compared to my 140 ft end-fed.* * * *I'm often running QRP on these bands, CW and digi modes only. * * * *de k3eui? barry* |
Re: Apologies if flogging a dead horse! CAL Correction?
Stan, thank-you for your input. As it happens, from the timing of your post I
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was actually at the same time watching the W2AEW youtube video on calibration where he demonstrated the Correction switch in passing, so I have an answer. I shall go back to my friend and inform him of the need to update his firmware in respect of the missing Correction option. 73 DE G4SDW Gareth On Mon, Mar 3, 2025 at 11:43 PM, Stan Dye wrote:
Oh, and the 'correction' option in the menu is in -newer- nanovna firmware, so |
Re: Apologies if flogging a dead horse! CAL Correction?
Oh, and the 'correction' option in the menu is in -newer- nanovna firmware, so if your friends doesn't have it, he doesn't have the latest firmware.
So yes, this was a valid question to ask, since the correction option is quite recent, and is not in the older documents or videos. |
Re: Apologies if flogging a dead horse! CAL Correction?
Gareth,
This option is simply a switch that turns the calibration on and off. When it is checked, it is on. But the main status is at the left side of the display, along the center-left edge. If there is a capital 'C' there in white, the calibration is on, and the number after the calibration indicates which memory slot it was read from. If there is a '*' instead of a number after the C, it means you either haven't stored the calibration or you loaded it from the SD card. It will probably help you to read the "Absolute Beginners Guide to the NanoVNA" (available in the files section of this group), and to watch some nanovna 'getting started' videos on youtube - there are tons of them. The ones by W2AEW are particularly good. Note that many of the videos were done a couple of years ago with an earlier version of firmware, which didn't have as many features. So the items in the menu system may look a bit different - but everything is still there. Stan |
Re: Apologies if flogging a dead horse! CAL Correction?
OK, thanks for that reference, but how do I know whether or not
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the correction is being applied? Is there a status flag? ie, after doing a calibration, do I leave the Correction option alone or press it once? A friend who has a newer VNA says that he doesn't have a Correction option in his CAL menu On Mon, Mar 3, 2025 at 06:05 PM, PT wrote:
Basically it toggles your calibration off and uses the base cal in the unit. |
Re: Apologies if flogging a dead horse! CAL Correction?
Basically it toggles your calibration off and uses the base cal in the unit.
/g/nanovna-users/topic/53015012?20,2,0,0 |
Re: S-Parameter Plotter
Off Topic...
Brian, I have fond memories of your Antenna modeling program - from back in the day.. I would load parameters and let the computer run all night. I didn't have a co-processor nor could afford the $99 then $69 for one, as time went buy. Life happened, my job took me Detroit to The DC area, then up to Boston area, then out here to Wichita Kansas, and then retirement. 24 years ago my wife Ann passed and left me a 10 year old boy to raise.. That ended ANN-tennas - a swap & shop business that has been dormant since. However as your antenna modeling software took a back seat, I went on to EZNEC and enjoy that even today. So thanks for the memories and the contributions to Ham Radio. If you ever get to "cow town" Wichita, Kansas let me know I have some no fertilizer (can't afford it) no hormones, (why?) grass fed born and raised on my 25 acres - irradiated (100watts) under my homebrew antennas, steaks we can put on the grill. I also have some Canadian beer as my grandkids live in NY and I bring it back from Buffalo. Maybe we can start a beer can antenna of your design.. Larry W8LM ARRL Life member Licensed 59 years. past President 2 terms, VFW post 3115 Amateur Radio Club, W?VFW, Wichita, KANSAS |
Apologies if flogging a dead horse! CAL Correction?
I've only just found and joined this group and am using a donated VNA
for the first time. So I apologise if I am repeating a topic that is hidden deep within the history of this group. In the CAL menu there is a Correction option but I cannot find any mention or explanation of it despite Google being my friend, and it is not covered in G4WNC's book, "NanoVNAs Explained". What is the purpose of the CAL Correction option and what effect does it have on the VNA? TIA ES 73 DE G4SDW Gareth |
Re: nano vna h black screen
Thank you, Thank you¡ that did the trick. Your help and patience is much appreciated, I learned something today, now if i can just remember it. This technologically challenged old F er really appreciates you taking the time to help. Thanks again.
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Cheers On Mar 2, 2025, at 8:07?PM, Stan Dye via groups.io <standye@...> wrote: |
Re: nano vna h black screen
You must use only the upgrade/verify portion of dfusedemo. If you first used the upload function, you overwrote your firmware file with the content of the nanovna, trashing it before you used it for the upgrade/verify function. [The dfusedemo program uses the "upload" term to refer to fetching data from the nanovna].
So it is worth trying again with a fresh copy the H4 file newly downloaded. |
Re: nano vna h black screen
Thankyou for your help and especially your patience.. I didn¡¯t realize i needed the H4, but same result.
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On Mar 2, 2025, at 7:09?PM, Hugen via groups.io <hugen@...> wrote: |
Re: nano vna h black screen
So.. i got the driver installed, showed up as ¡°stm device in dfu mode¡±, stm cube programmer did not recognize the bna but the dfuse demo program did, the ¡°upload action¡± part of the programer seemed to work but took only a second or two, the ¡°upgrade or verify¡± section did an erase and upgrade and seemed to finish ok, screen shot attached, still no joy. Just a black screen..
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On Mar 2, 2025, at 5:35?PM, Tim Dawson <tadawson@...> wrote: |
Re: nano vna h black screen
The version is typically part of the model number on the sticker on the case. The PCB is the same for the MS and SI - only the chip vendor changes.
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On March 2, 2025 5:27:50 PM EST, "VA4BG via groups.io" <bobgau@...> wrote:
Thanks for the reply, nowhere on the board do i see any reference to ms,si or zk, where should i be looking? Also have installed dfuse demo but running cannot get the correct driver. Looked in the files section and on stm site but cannot find a driver for win 11.On Mar 2, 2025, at 3:06?PM, juancb via groups.io <juancb@...> wrote: --
Sent from my Android device with K-9 Mail. Please excuse my brevity. |
Re: nano vna h black screen
Thank you, will get back to this later this evening, it did come in a case, if the version is not on there i will check the chip. Will let you know how it goes
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On Mar 2, 2025, at 4:59?PM, Stan Dye via groups.io <standye@...> wrote: |
Re: nano vna h black screen
From your photo it appears you have a NanoVNA-H4, (the 4 is for the 4" screen) hardware version 4.3, or perhaps a good clone. Did it come in a case, or was it just the card and screen? Most 'official' ones of these sold were in a case, and the back of the case had a sticker indicating the hardware version number, which was 4.3_MS for the MS version, and just 4.3 for the SI version. The ZK version is newest, and has different hardware - I think rev 4.4, so you likely don't have it. If you have a magnifier, you can look at the 5351 chip (it is the very small one with 5 tiny legs on each side) and see if its part number starts with MS or SI.
If you use the wrong firmware file, you will likely get a black screen. Make sure that if your version of STM32CubeProgrammer ends in .16, you first do a "Full Chip Erase" function before upgrading the firmware (versions before and after .16 automatically include the erase). Regarding the firmware, you need the one with H4 in its name, from Hugen's website as previously linked, or from DiSlord's NanoVNA-D github. While it may be nicest to get the correct SI or MS version, either one will work, since they are the same except for the SI/MS initialization, but that setting is also in the Config->Expert Settings menu, and you can choose the correct one after firmware installation. The driver in Windows 11 that Windows reports as the best one for your device will work fine with the STM32CubeProgrammer, but not DfuseDemo or nanovna-app. Some time ago I did a writeup about the firmware update and drivers that may be of help to you, see the files at this link: /g/nanovna-users/files/Miscellaneous/DFU-mode%20Driver%20for%20Win10Win11 |
Re: nano vna h black screen
Device manager just tells me best driver is already installed but all i get is stm bootloader showing up in USB devices
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On Mar 2, 2025, at 4:27?PM, Bob Gauthier <bobgau@...> wrote: |
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