Hi Lloyd, Unless the type F material is far more effective than 31 material, why pay $20 each? Mouser has the Fair-Rite 2.4" #31 core for $7 each. That is the lowest price I have found for small quantities and is where I get mine. Part number 2631803802. Pay no mind to the picture on the Mouser site - it's not correct.
73, Paul N1BUG On 08/29/2011 05:00 PM, Lloyd Berg N9LB wrote: > Hi Tod! > > Thanks for the data. > I'd like to build up several toroid chokes for 160, 80 and 40 meter use. > I looked at the Fair-Rite site, no 31 material. > I looked at their vendors and went to Amidon > ...amidoncorp.com/items/19 > > Amidon does have "F Material Ferrite Toroids" > " High Saturation flux density at high temperature. > For power conversion transfomers. > Good noise suppression from 0.5 to 20 MHz." > > They offer an "F material" core: > FT-240-FC ( $20.00 ea ) > Inner Diameter 1.4 > Outer Diameter 2.4 > Height 0.5 > Al Value 4107 > > Is this material suitable or am I barking up the wrong tree? > > 73 > > Lloyd - N9LB _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK