Topband: Impedance Matching Transformers for Receiving Antennas

[Bill Hohnstein KØHA]

>          I agree it is excellent but I viewed it as somewhat dated since
> it did not test the binocular style core of 73 material that many are
> now using.  W8JI describes this on his site and it has the advantage
> of being MUCH MUCH easier to wind than multiple quadrifilar turns
> interlaced on a toroidal core.

There's not that much difference between the BN-73-202 binocular
core being referred to (8500 mh/1000 turns) and the "upgraded"
FT-87A-J (6040 mh/1000 turns).  This is an improvement over the 
FT-87-J (3020 mh/1000 turns) referred to in the Bill Bowers, John Bryant 
and Nick Hall-Patch, VE7DXR article.   They document how quadrifilar
windings don't provide much advantage to overlapped windings. The 
FT-150A-J will take you to 8370 mh/1000 turns but is becoming excessively 
large for receive only applications.

73,  Bill     K0HA