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Yes, If I get within two feet of my coil at resonance, I can see the Q start to drop. I use about 10" of styrofoam to get the coil away from the Q meter, probably not far enough, but it's the best I

I'm sure you're right, Jim. I think most experimenters grab whatever is at hand and press it into service as a coil form. No telling what its characteristics really are. At one time or another I've

On 10/11/22 7:21 AM, Brian Beezley wrote: > After much searching, I was able to locate D-2852, the ASTM standard for the styrene pipe coupling. As expected from the application, it does not contain

Hi Brian, Those Qs are higher than anything I have made, However, I would like to see a real world case on PVC that has a higher Q than my so called styrene coupler. Can you run my coil? Dimensions

After much searching, I was able to locate D-2852, the ASTM standard for the styrene pipe coupling. As expected from the application, it does not contain any electrical specs. Here's the description

Well, with the H version, the solder on the LCD's ribbon cable can sometimes crack and cause the white screen. I had this on one of my units. You need to VERY carefully run a thin wire under the metal

Excel does allow you to curve fit and then find an extrapolated value. It will provide you with the curve fitted formula.

Your antivirus program is probably keeping you from opening the ZIP file. Send the file to https://www.virustotal.com/gui/home/url to assure yourself that it's virus-free and then disable your

I can open the above page but the Coil.Zip keeps say connection reset while loading. I think that would depend on the crystal set builder. I was active on the now *defunct 'The Radioboard' crystal

1. Use this program to calculate coil inductance and Q. It models skin effect, proximity effect, and more subtle effects for both solid and Litz wire: http://ham-radio.com/k6sti/coil.htm Results agree

That is true in some circumstances, it depends on the inductor in question and the frequency. For a 240uh air core inductor at BCB frequencies, I doubt silver would beat litz, because of skin effect.

Hello Mikek, From my point of view it will be better to use thick silver-plated copper wire for high-Q inductors. -- Bert W

I'm having the same problem with my H4 and started exactly the same way! I tried with a different FW but the same results... So it would be nice to know if someone resolved this issue successfully?

Absolutely, the form I showed in the picture uses a styrene form, styrene is high on the list of low loss materials. I was borrowing someone else's time and lathe work or I would had the form turned

Coil forms contribute dielectric losses. It's fairly common to see coils that use plastic rods or strips rods to keep the windings appropriately spaced while minimizing dielectric losses.

Yes, the capacitor loses will be much less than the inductor. A very good air cap can have Qs from 8,000 to 20,000. A really good Q for an inductor is 1400, but some have built BCB inductors near

My observation/experience with inductors that large (~240uH) at those frequencies is caused by two effects: 1) skin effect 2) proximity effect. The latter being less known about yet a significant

That is why I have the question, from my quick reading of the paper, it seemed like the author separated them, but I agree with you, at resonance you can't separate them. By extrapolate to zero, here

If you use a resonant circuit to find the Q the loss with be combination of both the L and C. You can only separate it if you can independently measure the loss of the coil or capacitor without the

The NanoVNA-H suddenly has a white screen. I am able to use a PC and it seems to be working. This afternoon was going to see if I could work my way thru the problem and the battery was dead. After