The OP asked about a 10m choke. Take a look at the Fair-Rite complex
permeability charts and you'll see that at 10m the ratio u'/u''for #61
material is 1.3 - that's a _lower_ ratio (lower Q) than #31 at 160m or
#43 material at 80m.
I wouldn't recommend #61 for lower frequencies, but the OP specified 28MHz.
Steve G3TXQ
On 20/05/2014 08:09, Jim Brown wrote:
Nor do I, but the #61 chokes I've measured are in the range of 4-5.
Compare the data sheets at the beginning of the Fair-Rite catalog for
#31, #43, and #61. For the first two, u'' is greater than u' by a
factor of about 1.6 in the range of 30 MHz, while for #61, the
relationship is the opposite, and by a similar ratio.
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