Re: Best NANOVNA Version that displays reactance, not uH & C
Well, I see the Polar/Rect menu options, but I don't see anything about the nature of the reactance display. Mine must be from before they added that. What hardware and firmware do you have? (No rush,
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Tom AE5I
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#33395
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Re: Variation in readings of R value
Thanks.
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alan victor
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#33394
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Re: Best NANOVNA Version that displays reactance, not uH & C
Hi Roger- Thanks very much! I had looked for that and didn't find it, but I'll look again. Mine's pretty early. Might have been added between the time mine was made and yours? Thanks again... Back to
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Tom AE5I
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#33393
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Re: Variation in readings of R value
Rules of thumb are handy, but today it's easy to directly optimize a coil design. The first image show's Mike's coil. The second shows it after optimizing turns and coil length. The third is after
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Brian Beezley
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#33392
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Re: Variation in readings of R value
Hi Mike. I suspect that the dielectric loss of your coil is secondary. A Qul of nearly 350 implies to me that the primary losses are likely copper wire R and fixture. A couple of useful things to do.
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alan victor
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#33391
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Re: Variation in readings of R value
No I wouldn't use black for that reason. It's white (see photo further up this thread). It's solid, not foam. -- Mike
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Mike
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#33390
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Re: Variation in readings of R value
Ohh. Black ABS? As in Drain Waste Vent (DWV) pipe? The black is from carbon black as a pigment - yeah, as in resistors Also, most DWV is what is known as "cellular" which means that the walls are
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Jim Lux
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#33389
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Re: Variation in readings of R value
After all that debate about PVC I've just discovered that my coil former is actually ABS ... Apologies! -- Mike
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Mike
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#33388
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Re: Variation in readings of R value
Thanks for all your comments, Jim. I think I've seen different dissipation factor values for PVC depending on filler amount. I believe I used values for pure PVC, but I can't remember. In any event,
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Brian Beezley
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#33387
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Re: Variation in readings of R value
On Tuesday 04 July 2023 02:54:32 pm Jim Lux wrote: > On 7/4/23 11:16 AM, WB2UAQ wrote: > > Mike and Alan, > > I measured the loss factor for PVC and it was about 0.005 or so at 1 kHz. I did more
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Roy J. Tellason, Sr.
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#33386
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Re: Variation in readings of R value
On 7/4/23 12:24 PM, Brian Beezley wrote: > On Tue, Jul 4, 2023 at 11:54 AM, Jim Lux wrote: > >> >> PVC pipe has two potential problems as a coil form (based on experience of >> folks building tesla
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Jim Lux
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#33385
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Re: Inductor model
Just 4 turns. The idea and constructive details came in 2015 from Jim Giammanco N5IB, the original designer of the PHSNA. Ignacio
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EB4APL
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#33384
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Re: Variation in readings of R value
I asked Google AI whether PVC is hygroscopic. Here, in part, is what it said Polyvinyl chloride (PVC) is a hygroscopic powder material. Hygroscopic substances can take and hold moisture from the
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Brian Beezley
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#33383
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Re: Variation in readings of R value
On 7/4/23 11:16 AM, WB2UAQ wrote: > Mike and Alan, > I measured the loss factor for PVC and it was about 0.005 or so at 1 kHz. I did more measurements at RF but will have to go back to old note books.
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Jim Lux
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#33382
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Re: Variation in readings of R value
Mike and Alan, I measured the loss factor for PVC and it was about 0.005 or so at 1 kHz. I did more measurements at RF but will have to go back to old note books. I made a simple fixture to test a
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WB2UAQ
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#33381
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Re: Variation in readings of R value
It's PVC water pipe. -- Mike
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Mike
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#33380
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Re: Variation in readings of R value
Most coils have some parasitic C (it can be quite large). That C has a voltage on it, and a lossy dielectric leads to loss.
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Jim Lux
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#33379
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Re: Variation in readings of R value
Hi Pete. The inductor is supporting a propagating field. It is both magnetic and electric. You are correct, while the magnetic properties of a core are key to control loss, so are the dielectric
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alan victor
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#33378
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Re: Best NANOVNA Version that displays reactance, not uH & C
You can change the setting in the menu to display R+jX instead of the default R +inductance/capacitance. Roger
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Roger Need
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#33377
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Re: Variation in readings of R value
Alan, How does the loss factor of the dielectric that the coil form is made from impact the magnetic circuit? I have heard others mention this but with no explanation. Thanks, Pete
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WB2UAQ
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#33376
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