Re: Sweeping an Antenna from the Shack
Terry Turner, W5ETG, now a silent Key, was the first to develop the twinlead J-Pole back in the 1960's.? ?That puppy has certainly traveled far!? ?The hard part today is finding Twinlead! hihi
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KENT BRITAIN
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#24775
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Re: Sweeping an Antenna from the Shack
Here's an example of a 6BTV with 100 ft of RG-8X. Blue trace is cal at the NanoVNA Orange trace is cal at the end of the Coax. You can pretty clearly see the loss of the coax increasing with
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Jim Lux
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#24774
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Re: Sweeping an Antenna from the Shack
If you sweep with your calibration plane at the antenna, and at the VNA, I would like to see those results... 73, and thanks, Dave (NK7Z) https://www.nk7z.net ARRL Volunteer Examiner ARRL Technical
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Dave (NK7Z)
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#24773
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Re: Sweeping an Antenna from the Shack
SO-239 are not so bad at VHF, and in theory the affect generated by the connectors, in general, is equal across a broad frequency range. If you are within that range, then the connector type is not an
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Dave (NK7Z)
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#24772
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Re: Sweeping an Antenna from the Shack
I think |S11| = -20dB is more like 1:1.22 VSWR 1:1.1 is 26 dB 1:1.5 is 14 dB 1:2 is 10 dB https://www.amphenolrf.com/vswr-conversion-chart
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Jim Lux
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#24771
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Re: Sweeping an Antenna from the Shack
Thanks. The reason I'm doing this is because I made a blog post about how to design a 2-meter twinlead J-Pole using SimSmith and the NanoVNA. One of my readers asked me to post a final sweep of the
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Albert Pion
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#24770
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Re: Sweeping an Antenna from the Shack
Yes, you will lose a bit of dynamic range. However, consider the "raw" dynamic range of the NANOs. At 2-meters, you have more than enough dynamic range in the instrument to throw away a bit. Actually,
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W0LEV
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#24769
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Re: Sweeping an Antenna from the Shack
You'll lose a little bit of dynamic range, but, really, how much do you need.? If your antenna has a |S11| of -20dB or -30dB, then the fact that the dynamic range is now 50dB instead of 60dB isn't
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Jim Lux
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#24768
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Re: Sweeping an Antenna from the Shack
You loose a few dB of dynamic range, but since a 20 dB RL is the same as a 1.1 to 1 SWR,I'm sure you have plenty of dynamic range! hihi? ?And now you know why so many of us like to work in Return
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KENT BRITAIN
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#24767
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Re: Sweeping an Antenna from the Shack
That's interesting. I didn't think of using return loss instead of VSWR. I was thinking my VSWR would be much improved at the end of a lossy cable and I couldn't think of a way to correct for it. But
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Albert Pion
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#24766
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Re: Sweeping an Antenna from the Shack
Hi Albert You can cal at the end of the coax, but you don't have to. Lets say the coax has about 2 dB of loss.2 dB of the signal is lost going up, and 2 dBis lost coming back down.Thus the antenna is
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KENT BRITAIN
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#24765
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Re: Broken S-A-A v2 ?
I had the same problem, which appears when making the calibration and SHORT probe does no electric contact is made with the CH0 connector. Solving was by tightening the warm wire in the CH0 connector.
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Eugen YO9VA
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#24764
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Sweeping an Antenna from the Shack
I want to sweep my 2 meter antenna from the end of a 15 to 18 foot coax. This is because I need to get the antenna out in the clear away from nearby objects to get a good indication of the actual
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Albert Pion
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#24763
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Re: Do I return my H4? Hima brand
#buying
#hardware
#nanovna-h4
Although as an e-mail subscriber it can be frustrating to see a whole string of messages all but one of which say "Edited message" (or whatever it is). Of course, it's a very useful feature at times,
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David J Taylor
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#24762
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Re: Do I return my H4? Hima brand
#buying
#hardware
#nanovna-h4
FYI, when you're looking at your own posting, underneath are 3 links that say Reply Like More If you click on the "More" link, you can choose to edit your post (and correct typing mistakes). I have
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DougVL
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#24761
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Re: Do I return my H4? Hima brand
#buying
#hardware
#nanovna-h4
Buy, I meant *buy* an original Hugen NanoVNA!
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Stephen - 2E0FXZ
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#24760
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Re: Do I return my H4? Hima brand
#buying
#hardware
#nanovna-h4
Update. I did return the non Hugen "NanoVNA". Call them fakes, counterfeit, clones or what you will. The clone's branding and packaging is clearly intended to deceive the purchaser. I have now
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Stephen - 2E0FXZ
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#24759
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Re: Focus on the Fundamentals. #newbie #tutorials #learning #general vna
#faq
#applications
#newbie
#tutorials
#learning
I think these RF test boards help, trains you on results, if you have set the vnanano up and calibrated correctly, getting the prescribed results gives us ou some confidence in the nano.
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RayGil <ray.gilchrist.1963@...>
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#24758
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Re: Do I return my H4? Hima brand
#buying
#hardware
#nanovna-h4
Interestingly, inside KEIL, STM32F302CB and STM32F302CC use the same memory description file. So in fact STM32F302CB and STM32F302CC may use the same Die, just marked as different models when
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Hugen
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#24757
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Re: Measuring a Capacitor.
A cheap LCR meter is also a good option for measuring variable capacitors. The value of most types of capacitors does not vary wildly with measurement frequency. The value of inductors does, which is
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Shirley Dulcey KE1L
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#24756
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