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@elanpaim33 8 күн бұрын
great info how ever you need to add common mod balun the noise you getting is from non adding common mod balun I had the same issue however after adding the common mod balun all noise a re gone I hope this will help you vy 73 elan
@leomartihart 9 күн бұрын
jaja que los ingenieros no miren el video!!! Importante la calibracion. gracias por tu trabajo.
@ReefMimic 13 күн бұрын
Don’t worry you’re not the only one. I Cleaned my work table in the garage only to clutter it back up again.
@rjy8960 13 күн бұрын
I'm really nervous about Ali Express and counterfeits. I've become more jaundiced against pile-em-high and sell-em cheap merchants. I've seen a lot of really good reviews of the MLA30+ which are on KZbin I am surprised by the results that you have experienced. I've had massive interference problems at my QTH and ended up as a last-ditch a few years ago going for a Wellbrook loop. Sadly they are no longer in business and the proprietor passed...long story short the design was "copied" by a UK amateur as the "Wellgood" amplifier which may be worth having a look at. I bought one as a backup in case the amp in mine decides to go. The amp is not expensive. I did a short 1:47 video on the differences between a resonant dipole on 60m and my Wellbrook and the differences in s/n are chalk and cheese - I pretty much use my loop all of the time for <10MHz receive with my TS-990 and the FT-2000 that pre-dated it. Not sure if the link will work - kzbin.info/www/bejne/pJWtk3ymd7l_opo 73 de Richard M0SNR
@philswede 13 күн бұрын
Where did you get your "shell" or that green frame for the vna in your video thumbnail?
@ve6wo 13 күн бұрын
KC3UDZ makes them! www.qrz.com/db/KC3UDZ
@philswede 13 күн бұрын
@ve6wo Greetings from Sweden! I appreciate your quick response and also the link. Will check it out now.
@darylcheshire1618 21 күн бұрын
I have 20m of RG-213 which sat on the floor of my garage for 20 odd years. It seems to be working normally but I’ve since got some RG-58. I have ordered my nanoVNA and will look forward to check if this cable has any loss. At the moment it seems neglible.
@DaffyDuck35 25 күн бұрын
Thanks a lot for your share !
@donepearce Ай бұрын
Please abandon VSWR and use return loss (in dB). You get so much more information, particularly when you have a good match. And do remember that you are measuringa combination of radiation resistance and loss resistance. You don't want to end up matching into a loss resistance.
@renaat9829 Ай бұрын
👍👍👍👍😊😊😊😊
@vladtepes481 Ай бұрын
You need to know the impedance at the antenna. To do this, the reference plane must be at the antenna feed and not in the shack.
@aWeRCHeli Ай бұрын
But he shifted the reference plane to the part of coax, where antenna is connected -e.g. beginning . This should allow the same measurement as it would be directly connected to the antenna.
@riadhalgamaty8844 Ай бұрын
Thank you very much for your detailed explanation. May I know how to get same cable that you used? From wich srore
@ve6wo 12 күн бұрын
I ordered mine off Amazon. Simple :-)
@herbmasonjr.8173 Ай бұрын
Xtra nice video! ~ Very educational! ~ Thank You!
@nateitkin8279 2 ай бұрын
That was very good. You've inspired me to make some coax measurements with my NanoVNA.
@sc20910 2 ай бұрын
I’m confused, why are you looking at matching the coax 50 ohm *impedance* with just the resistive part of the impedance of the LoG antenna? I’m wondering why you didn’t add that to your callcs for the antenna impedance. Or was it a small enough capacitance that it didn’t matter?
@petergore1972 2 ай бұрын
Peter Gore Seer, I Have AMLA-30, On A Trio,R-2000, Its North To South, With The Magnetic Poles, Its Working Good And My RF Switch Works At Its Best With Antenna.
@AdamosDad 2 ай бұрын
When the loop is horizontal, it becomes an omni-antenna with little Near vertical incidence skywave.
@richytug7612 2 ай бұрын
Thanks a lot for detailed description! 73!
@volodymyrzakolodyazhny7740 2 ай бұрын
To 43:00 - 0.77 dB loss is fine because each connector adds 0.1 dB roughly. So, you may have 0.2 dB loss in connectors and 0.57 dB loss in a cable. Which is very close to 0.6 dB/100 ft.
@volodymyrzakolodyazhny7740 2 ай бұрын
Thank you for explanation. I just want to add than a point with +180 phase degree or -180 phase degree in not a resonance. It's just a point where phase goes more then 180 degree and nothing more. A device is made to show phase degrees whithin a range -179.99 to +179.99.
@raulgongora5288 3 ай бұрын
Twaskyou sr very interesting. Blessings
@amessiah_ 3 ай бұрын
Calibration, with same connected cable, isn't how is supposed to be. All this connected adapters, cables - must be removed before calibration. After, you need to set electrical delay (port extension), to each of those connected adapters/cables
@jarmstrong2843 3 ай бұрын
Good video. What you did is not really different from what I have seen on other videos. So, I think you are safe providing good information.
@FUNKLABOR_DL1LEP 3 ай бұрын
4:41 Hi, great job! I saw You turning the SMA connector into the SMA nut, You should always turn the nut and not the adapter. if You turning the Adapter, it is rotating in the connector, this will damage it over Time. 73 de DL1LEP
@ve6wo 3 ай бұрын
You are correct. Since this video was made I have started to support the coax with one hand to allow the nut to rotate while preventing the center pin from rotating.
@carelmulder8035 3 ай бұрын
Thank you very much for this very informative video Gregg. Have a nice Easter weekend, PA0CMU
@ve6wo 3 ай бұрын
Thank you. I’m glad the video was helpful :-)
@Miller7747 3 ай бұрын
You can also use a spectrum analyzer and tracking generator
@BruceRobertson 3 ай бұрын
Great video!
@richardchambers256 3 ай бұрын
Great information! You andwered my questions in the first 3 minuits. Thx. W6rch
@JimSky 3 ай бұрын
Seems like the test fixture should be used in the calibration of the VNA.
@gorak9000 3 ай бұрын
The phase going from -180 to +180 doesn't mean anything - the phase is linear (has a linear slope to it), it's just if you keep plotting it without resetting it at some point, you end up with phase angles above 360* which ceases to mean anything, or is hard to work with. So the rule of thumb is you graph phase from -180* to +180*, and if it goes below -180 or above +180, you wrap over to the other side. Also, the phase being positive or negative has nothing to do with it being capacitive or inductive - it's not on the same scale as a smith chart. The phase plot has absolutely nothing to do with capactiance or inductance, only delay.
@ve6wo 3 ай бұрын
I have to disagree, somewhat. Although the phase rotating from -180 to +180 doesn’t really have any particular significance as far as I know, as you pointed out… the phase angle (as displayed on the VNA and on the smith chart) is most certainly related to the resistance and reactance in the device under test, which could present as capacitive or inductive depending on what the stimulus frequency is. Although the phase angle on a smith chart is generally explained to represent the distance in wavelengths along the transmission line, when you look a little deeper, you’ll find that this phase angle is actually the phase of the reflection coefficient, as measured at the point where the VNA was calibrated.. the calibration plane. Negative phase values represent capacitive reactance as seen at the calibration plane, positive values represent inductive reactance as seen at the calibration plane. Please watch this video where I explain the mathematical relationship… kzbin.info/www/bejne/Y5iqe3uef5efi9Usi=MkYxI0Tc5-SnjL4i
@gorak9000 3 ай бұрын
@@ve6wo Still my overall point is if you look at your phase diagram, and simply remove the jumps from -180 to +180 (which is only a notational convention to keep the scale of the phase graph contained), you would have a straight line continuing infinitely with the same slope. A "linear phase" shift shows you that basically nothing odd is going on with the DUT (the cable in this case) - it's just getting electrically longer in terms of wavelengths, as the frequency increases, which makes perfect sense as the wavelength decreases as the frequency goes up, so the cable looks longer when measured in # of wavelengths. Also, a smith chart doesn't display phase information - it only displays complex impedance at a given frequency. Maybe there's a mathematical relationship there between complex impedance and phase (or the derivative of complex impedance and phase maybe), but I haven't thought through that. I will watch your other video, but I'm skeptical...
@ve6wo 3 ай бұрын
@@gorak9000 That’s fair :-) Let me know what you think after you watch the other video.
@SuburbanDXing 3 ай бұрын
Good video, Gregg. My video on the LoG was among the first on You Tube and I have been using it for several years with very good success. That said, it was NOT a success at my late father's QTH, as a pesky noise source rendered the LoG ineffective. Your video echoes his experience with this design. The LoG is certainly an antenna worth trying, but as in life, there are no guarantees. Thank you for posting this (to give the other side of the coin) and 73! de WX0V
@ve6wo 3 ай бұрын
Thank you for taking the time to leave this comment. I appreciate it.
@jptucsonaz8503 3 ай бұрын
Hi Gregg, a suggestion... Instead of metal nails into frozen ground (i.e. highly conductive!), Try using plastic stakes. You may need to drill a few holes into the frozen ground, but I think you may find the nails are inducing the ground noise. I can't really duplicate your issue here in the desert - haha...😆 73
@ve6wo 3 ай бұрын
It’s worth a shot!
@phildurall7466 3 ай бұрын
Gregg ... Nice video coverage and method reviewing your results Sir! I too tried this same type of loop at my location and came to the same conclusion as you. I do have a noise canceller that I think I might give a spin in the future. Thanks again! 73 - KF6IF
@ve6wo 3 ай бұрын
That’s neat to hear! I thought I was special… hahaha! The only one who has a loop on the ground noise magnet, when everyone else who tries it has amazing low noise receive… 😂
@ZeroHarry 3 ай бұрын
Curious to see if the loop on the ground would be more effective if you were comparing it to a vertical antenna. Thank you for the video.
@phonix6494 3 ай бұрын
Are you mastering your videos in HDR?
@ve6wo 3 ай бұрын
I’m not that technical with the videos. They are shot using my iPhone 13 Pro, edited on the phone using iMovie, and then uploaded to KZbin.
@patrickdemeyer2210 3 ай бұрын
i put it 2 meters up and defased it with a rod antenne on a corner , -135 dBm noise floor , at night 80 m perfect , daytime 20 , 40 meter ok.
@thomaskallmyr 3 ай бұрын
I like any program that take up the issue of Nano vna😊😊😊😊😊😊😊
@oh5rm 4 ай бұрын
At least lowering the antenna shifts the resonance down, which makes sense.
@danl3547 4 ай бұрын
Your metallic mast may be interfering with your setup. Generally, a dipole is mounted with non-metallic (dacron etc.) lines or a fiberglass pole.
@ve6wo 4 ай бұрын
Yes, the metal pole will likely have some effect. Also the metal roofing on my garage, and a host of other things unique to my location, all of these things will change how the antenna behaves. For most of us, we cannot control these environmental factors so we should be able to measure and tune and impedance match for each specific location.
@patrickdemeyer2210 4 ай бұрын
If you change the stimulus , you should recalibrate ... every time.
@R50_J0 4 ай бұрын
True that.
@ve6wo 4 ай бұрын
I have done this experiment.. at these low frequencies I observed no benefit. The readings were the same. If a person goes outside of the range of frequencies that were used to calibrate the nanoVNA, then yes, I will re-calibrate.
@patrickdemeyer2210 4 ай бұрын
Just buy a circular polarisation filter for the camera, takes the glare out of anything. en.wikipedia.org/wiki/Polarizing_filter_%28photography%29
@ve6wo 4 ай бұрын
I shoot these videos with an iPhone. I’ll have to see if someone has built a polarization filter for it.
@darylcheshire1618 21 күн бұрын
I got a tiny one for my dashcam to reduce the reflection in the windscreen.
@thomaskallmyr 4 ай бұрын
Very interesting indeed😊
@thomaskallmyr 4 ай бұрын
Ett fantastiskt this calculations you do😊😊😊😊😊😊😊😊😊😊😊
@vladskrypnyk6881 5 ай бұрын
Code 102 means 1000 pF, not 100 pF
@ve6wo 5 ай бұрын
Hmmmm, where in the video did I say 100 pF? I went to 10:15 in the video and checked.. I said 1000 pF 🤷♂️
@rfburns3472 5 ай бұрын
Very nice demo. I was about to do the same test. One thing I noticed, and it may be minor, is that you held onto the back allegator lead which may have induced some hand capacity in the measurement. Even though it was the black shielded allegator clip it still could have some effect.
@ramonbennett8416 5 ай бұрын
Nice demonstration, not to complicated to follow along with. Nice job 👍 KN6JHC
@g0fvt 6 ай бұрын
My MLA-30 redeemed itself too, recently bought another HF rig with dual receivers so with headphones you can listen in "stereo" with two antennas, one on each receiver. Sometimes the more readable signal is from the MLA-30, my noise levels are often very high on 40m, both with a 1/4 wave vertical and low dipoles. The MLA-30 is going to get some attention, probably a slightly larger loop and a decent mounting further from the house, they don't measure well for dynamic range but a great basis for some experimentation. FWIW I had already reduced my noise levels substantially with the combination of a current balun in the HF feeder to the main antenna and common mode choking of the electricity supply to the entire shack. 73