Re: Length Measurement
The VF for the TDR test will be the same no matter what length you cut the CAT6 cable. VF for a specific type of cable will vary by manufacturer and even different between production runs by the same
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Roger Need
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#33823
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Re: Length Measurement
For some reason, my messages are not making it to the email chain...they are in the groups.io online...
By
Geoff Peters - AB6BT
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#33822
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Re: Length Measurement
OK, I see what you mean, and I suspect the the VF can vary by 1% over the length of the cable. I will test with a piece of CAT6 by cutting one wire and reconnecting at one foot intervals.
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Geoff Peters - AB6BT
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#33821
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Re: Length Measurement
The resolution is 4.8 mm but the accuracy will be worse because you cannot enter the VF to more than two digits. So if the VF is 69.5 % and you have to enter 69 or 70% that will affect the calculation
By
Roger Need
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#33820
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Re: Length Measurement
Sigi, Yes, I have a piece of CAT6 cable to test. I removed the jacket at 1 foot intervals for about an inch. I will test by cutting 1 wire at a time at each location and see what I measure. Geoff
By
Geoff Peters - AB6BT
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#33818
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Re: Length Measurement
take 10 inch of speaker wire.. that should show almost similar numbers.. if thats the case then yes you can trust it dg9bfc sigi Am 23.08.2023 um 22:52 schrieb Geoff Peters - AB6BT:
By
Siegfried Jackstien
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#33817
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Re: Length Measurement
Roger, I sent a reply but it hasn't shown up so here's take 2... In this case, what I'm trying to determine is the minimum distance I can measure to a fault.. I used 4.8mm to simplify this discussion,
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Geoff Peters - AB6BT
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#33816
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Re: Length Measurement
Roger, Mainly I'm trying to determine the minimum distance to a fault that I can measure. I understand that the 4.8mm number is dependent on the VF, I was only trying to keep things simple for this
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Geoff Peters - AB6BT
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#33815
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Re: Length Measurement
You need to be calibrated over the frequency range that you select. However there is calibration interpolation used on some NanoVNA's, like the -H and -H4, so you can arrow the frequency range if you
By
Roger Need
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#33814
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Re: Length Measurement
Yes, that's what I do, not a problem...
By
Geoff Peters - AB6BT
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#33813
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Re: Length Measurement
Make sure you enter the VF as a percentage not a decimal value. EXAMPLE 60 not .60 *Clyde K. Spencer* wrote:
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Clyde Spencer
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#33812
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Length Measurement
I have a couple questions regarding using the Transform function to measure length of a cable. How does calibration affect the Thansform measurement? If I set the stimulus start and stop to 50KHz and
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Geoff Peters - AB6BT
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#33811
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Re: some Nano VNA SAVER 40m antenna graphs
That will be a very interesting comparison test! I hope you publish all the details and measurements. (Great choices of antennas, too. My full-wave horizontal loop is terrific.) -- Doug, K8RFT
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DougVL
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#33810
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some Nano VNA SAVER 40m antenna graphs
Getting Ready for the new **** MidAtlantic 40m NBEMS net **** testing: Saturday and Sunday 10 AM EDT on 7068 kHz (vfo) coverage over a 300 mile radius from Philadelphia THOR 22 check in THOR 56
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Barry K3EUI
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#33809
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Re: Buying new VNA
Nuno, I was pretty happy with my NanoVNA-F V2 until it randomly died on me. It lasted nearly 2 years though and had zero issues with it before it died. I took a gamble and purchased the SV4401A
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cnick6
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#33808
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Re: Buying new VNA
I forgot to add this link https://nanorfe.com/nanovna-v2.html
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Leif M
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#33807
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Re: Buying new VNA
The only potential downside to the V2 is that they are more sensitive to ESD, because they have a monolithic RF switch at the input.
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Jim Lux
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#33806
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Re: Buying new VNA
Likewise. I would recommend V2 Plus4 or V2 Plus4 PRO from an official store. There are several other version but I like V2 Plus4. Today perhaps PRO version. Battery lasts a long time and results are
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Leif M
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#33805
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what fw
i have finaly got my pc to tato the vna,ready to load fw,can anyone tell me what FW has the biggest fonts with the most save slots,thanks.
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Paul larner
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#33804
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Re: Buying new VNA
Is not easy as you said. It needs to be new design and higher speed components. See link: https://nuclearrambo.com/wordpress/reveiwing-the-new-nanovna-v2-saa-2-part-1/ FC
By
fcusa@...
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#33803
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