On 8/6/2014 8:31 AM, Carl wrote:
31 and 43 mix are the popular ones in the 2-30 MHz range for common mode suppression; 31 wins at 160 and 80, but 43 is better in the 7-30 range.
I would amend that only to say that #31 and #43 are roughly equivalent in the 5-15 MHz, range, #43 is slightly better above 15 MHz. #43 is a bit less expensive than #31, but the cost difference disappears if you buy #31 in quantity. My last group purchase of #31 2.4-in cores was for 1,100 pieces, about two years ago. We paid about $4.
Because #31 is so much better on 80 and 160, because it is more broadband below 15 MHz, and because it remains effective through the HF range, I long ago made the engineering decision to buy #31 in quantity for ham HF applications. If I were ONLY working above 80M, I would look at pricing on #43 in the quantities I needed.
73, Jim K9YC _________________ Topband Reflector Archives - http://www.contesting.com/_topband
