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The "frequency makes a difference" part of measuring inductance of any coil is the distributed capacitance factor. This apparent difference in measured inductance can be used to calculate the amount

Amidon is not a manufacturer but rather only a distributor of Micrometals materials. Micrometals has very interesting website. An interesting design program here:

Paul - ?KE7HR: ? I have the first edition of EMRFD, with the CD (though I have not opened the CD), so could provide programs on the CD to those interested. ?Email me at bwbangerter-at-yahoo-dot-com

All: Note that the only thing that will change inductance on a toroid winding is THE NUMBER OF TURNS. Pushing the turns together or apart seems to change it a little, but all one is really doing is

If it's any help, with my 30m version I was only getting about 1W out, with the power rising slowly to around 1.2W on a prolonged key down. I replaced the blue inner caps (they measured about 30pF

An example of different amounts of core coverage with a given number of turns vs. inductance is at: http://www.vkham.com/Info/ferro/wind_deg.gif As a practical matter, different mixes (stuff the

Left Japan 10/24/2017 arrived 11/1/2017 in Williamson, NY . Am at installing resistors stage now. ?72 George/W2BPI

I put a spreadsheet to calculate the different resistor values for a non-standard center frequency for the QCX CW filter in the files section of this group. It is based on the one I wrote for the

John Anything with a decent braid around the wire should work.? coax will work but controlled impedance isn't necessary. Its a lot less work if you can find an enclosure that lets you mount the

Peter So do iron dust cored inductors include a frequency term? If so just how much difference? My tests on air and ferrite cored coils have been with this

Does this "fact" only apply for iron dust cored inductors because the equations for the inductance of air cored coils do not include a frequency term. PeterO G0DZB

Yes, a scientific fact. Lee, w0vt

Its important to test your inductors against known standards (inductor of a known inductance). Just reading your LC meter and believing it can be very deceiving. Dr. William J. Schmidt - K9HZ J68HZ

< If I measure with a Fluke LCR mter that's still Chris, Somewhat? How much? What type of inductor? I've seem Lee's warning many times, I want to know when the variation might be significant. 73

An inductor tested at Lee, Have you any examples of this? All inductors I have tried with a lowish frequency tester and a GDO at working frequency have coincided with a reasonable accuracy. 73

Very good point. ?Been over 50 years since I had my theory classes and I had forgotten this point. ?I do have a Midnight Design Solutions Scalar Network Analyzer which can measure L at frequencies

About 30% efficiency... Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois Owner – Operator Villa Grand

Hello Lee, This is very true, I am experimenting with a new power amp and also a big LPF bank for it. If I measure with a Fluke LCR mter that's still in calibration it measures at (from memory)

Hello all, First off, this is my first attempt at building *ANY* amateur radio kit. I have been preparing (reading the instruction manual, reading all of the posts on this forum, watching build

Hi Hans, I added the U3S section 11. *Potentiometer tuning for the Ultimate3*?modifications to my v3.12 version but am getting problems. This is a U3S Transceiver using standard U3 Tx with relay