[Amps] confused reading amidon ferrite specs?

[R at contesting.com]

On Mar 7, 2006, at 9:03 AM, Jim Brown wrote:

> On Tue, 7 Mar 2006 08:56:08 -0800, R at contesting.com;Measures wrote:
>
>> On an oscilloscope, using 100w of RF, I observed that mix #61 begins 
>> to
>> distort the waveform at c. 13MHz.  Those who don't desire to generate
>> harmonics should probably follow the manufacturer's specs and not
>> operate 61 above 10MHz.
>
> The distortion and losses will depend on many variables, including the
> power level, the size of the core, and the number of turns.

Agreed.  Waveform distortion is the result of of a combination of too 
many Webers and too much f.

> What were your
> test conditions (core size, turns, etc.)?

I don't remember the details, Jim, however, as I recall it was a 2.4" 
mix-61, mu=125,  core for a 450-ohm 8170 grid terminator R.  Whereas 
everything looked wonderful on  the 'scope at 1W, at 100W, it did not.  
After I read Permag Pacific's tech specs on mix-61, it was apparent 
that the seller didn't.  As a result of seeing the harmonic distortion 
above 13MHz with 100W, I switched to mix-67 (mu=40, rated by mfg at 
80MHz max) and observed a clean sinewave at 29MHz.
>
> Jim Brown K9YC
>
>
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Rich Measures, 805.386.3734, AG6K, www.somis.org