Re: ferrite quality?


Steve Ratzlaff
 

Hi Ryan,

After looking at the ad, I'd say those Chinese rods would be fine, keeping in mind their length and diameter. And they're probably around 125 permeability as most standard transistor radio loopsticks are. (Most of the Russian rods are higher 400 permeability, and who knows what they were originally designed for; they would also take fewer turns for an AMBC coil of a given inductance vs. the nominal 125 permeability rods.) Lower permeability means more turns for a given inductance which equates to higher coil sensitivity for the same rod length.

For FSL use, rod diameter just means more rods are needed for a smaller diameter rid vs. thicker rods, for rods of a given length. For single loopstick non-FSL use, a fatter diameter rod is better (more sensiive), again for a rod of a given length.

73,

Steve


On 3/11/2017 9:34 AM, rmartin100@... [ultralightdx] wrote:
 

Does anyone know if the ferrite rods in this link are as good as the more expensive "Russian surplus" ferrite rods when used for AM antennas? The seller doesn't list the permeability.


http://www.ebay.com/itm/5pcs-140mm-5-5-Black-Mn-Zn-Ferrite-Rods-For-Radio-Antenna-Aerial-Crystal-/232051037011?hash=item360751d353:g:XfkAAOSwU-pXs9Y-


Thanks,

Ryan



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