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Hi, Thanks for the detail!!! If you find that study on various dialectic values for various materials, I would love a copy... I am making some VLF and HF ferrite bar antenna, and using CPVC to protect

Gary, Strange. Flux density, and thus heat production, happens in the bulk of the ferrite, not just its surface. They are strongest where the magnetic path is shortest, and that's along the inside

RG-58 is not appropriate for US amateur legal power. I don't use it. This is one of the main reasons I have chosen bifilar wound CMCs. I have enough RG-142 (Teflon silver coated and double shielded

The CMCs I have constructed and measured are NOT coaxial cable wound on the toroids which are presented in your reference. That presentation simply winds and measures (for the most part) RG-58 wound

Your finding don't compare well with the data found here. https://www.hamradiotoday.uk/G3TXQ_WEB/G3TXQ/www.karinya.net/g3txq/chokes/index.html Look at the 12 and 17 turn on RG58. Max KG4PID

ALL the modules are 3.3 volt devices but many have low output regulators in front. Get the schematic for the one you have and bypass the regulator to run it directly from 3.3v

I can not find a low voltage HC-05 module such as the 3.3v. Where did you purchase your module? Everyone I've found on line are of the 3.6-6v modules. -Thanks

A little of both - moisture adsorbing into the surface will increase surface leakage for HV, but after wiping it down with alcohol, the leakage resistance was still higher, so I think there's some

Chances are that I'm not interpreting your setup correctly, but based on the picture with choke and nanoVNS, you were only testing the DM mode - impact of your choke on power sent from one side to the

I suppose you meant MnZn (Manganese-Zinc)

You did not get power correctly :) P=Vrms^2/R, so if you have Vpp=175V (peak to peak), Vmax=Vpp/2=87.5V and Vrms=Vmax/sqrt2=87.5/1.41=62V and P=77W on 50ohm load

Hi, Thanks for the clarification, do you think this is due to the PVC itself absorbing water, or just moisture in the air? 73, and thanks, Dave (NK7Z) https://www.nk7z.net ARRL Volunteer Examiner ARRL

Yes - I think probably more due to porosity and filler than the actual PVC itself. If you go look up a plastics table, PVC is in the "generally non-hygroscopic" bucket (like PE, PP and PS) However, in

Ed, if you have S21 in terms of magnitude and phase, calculation of the series impedance of the device being measured is straight forward: Zdut = Zo*((2/S21) - 2), where Zo = 50 ohms for a 50-ohm VNC.

I am referring to the line: "It's also fairly hygroscopic..." Is this referring to PVC? 73, and thanks, Dave (NK7Z) https://www.nk7z.net ARRL Volunteer Examiner ARRL Technical Specialist, RFI ARRL

Jim, it was quite interesting to watch the PVC-wound CMC 'do its thing'. I certainly didn't need 2.4 GHz, just 40-meters at 400-watts. It was really rather fascinating to watch the SWR climb with

yes, it's kind of like nylon in that way, and unlike, say polyethylene, PTFE, or polypropylene, which "as delivered" tend to be fairly hydrophobic. From what I understand, depending on what kind of

Are you referring to PVC here? 73, and thanks, Dave (NK7Z) https://www.nk7z.net ARRL Volunteer Examiner ARRL Technical Specialist, RFI ARRL Asst. Director, NW Division, Technical Resources

PVC has a low melting/softening point, so it's sensitive to these kinds of effects. It's also fairly hygroscopic, but I doubt mois

Great! ...Larry