Re: Daylight radio toroids
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I agree whole heartedly with your comment. I am just going by the issues brought up with some other posts that were put on this group about core material, losses, eddy currents, etc. I have been a big fan of magnetic cores for years. Just trying something new and that is what this is all about. 73 Barry K3BO Sent from for Windows ?
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From: Mark - N7EKUSent: Friday, August 19, 2022 11:59 AM To: [email protected]Subject: Re: [BITX20] Daylight radio toroids ? Toroids and pitfalls?
What were the problems?? Toroids for use in HF have been the standard for high performance vs size for a long time.? Are there suddenly problems?? The only problems I can imagine are poor quality/unknown materials related to buying from questionable sources, or just choosing the wrong core material.? For the size, toroids using the proper magnetic material will give one the highest Q.? If not, then manufacturers would certainly be using very low cost plastic cores.? For?VHF, phenolic toroid cores have been used for decades because at VHF magnetic materials become counterproductive.? For HF if you choose not to use a magnetic core, then pretty much any RF neutral material will suffice.? One could use bobbin cores, rubber, balsa wood, 3d printing, whatever.
If you want to check your measurements, you can use MicroMetals "Toroid" program:
Just choose the closest core size, choose material type 0, input the desired inductance and it will give you the number of turns you need and show you the peak Q frequency as well as the self resonant frequency (which can become a problem as the number of turns grows)
73.
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