Topband: Core for K9AY loop transformer
k9ay at k9ay.com
Wed Mar 28 10:54:24 EST 2007
>>I almost exclusively use 73 materials for broadband .5 to
>>30MHz receiving applications.
> I use a pair of large type 43 toroids with 10 turns of RG6 feedline
> through them for my common mode suppressors on my Beverages.
> Are you saying this is a poor choice?
> 73, Richard - K5NA
For a common mode suppressor, you simply want enough inductive reactance to
impede current flow. The type of core does not matter -- air, low mu or hi
mu materials -- as long as the result is at least a few hundred ohms
reactance. 10 turns through 43 material is roughly 1000 ohms at 160M, which
should work well.
On the subject of transformer cores, Fair-Rite 77 material is also excellent
for 160M. It has similar mu and lower loss specs than 73, although the
difference may be hard to measure in an actual transformer.
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