[TowerTalk] Binocular Core Winding - A Summary

D. Scott MacKenzie kb0fhp at comcast.net
Sat Dec 30 13:51:44 EST 2006


First off I want to thank everyone that responded.

>From http://w7iuv.com/flag.htm using a Amidon BN73-202 binocular core - 3
turns primary, 12 turns secondary.

>From http://www.w8ji.com/k9ay_flag_pennant_ewe.htm using a Fair Products
2873000202 binocular core - 2 passes primary, and 4 passes secondary...this
looks like a single turn primary, and a 4 turn secondary.  He uses a
balancing pass to reduce stray capacitance.

>From RA6LBS [ra6lbs at volgodonsk.ru] he recommends 2 turns primary and 8 turns
secondary.....

The common thread in each of these recommendations, is 4:1 Secondary to
Primary passes

>From Mike [k4gmh at arrl.net] he indicates that: "each time you poke a wire
through one of the holes in the binocular core that counts as a turn.  So,
for the two turn primary, make a hair pin out of the wire and stick one side
of the hair pin into one of the holes in the core and the other wire side
into the other hole in the core - 2 turn primary."

Have I missed anything?

I have a bunch of the binocular cores, and will build a couple, with a
resistor across the secondary, to see how they work, and to see if I can
build the proper transformer.  Should I use a potentiometer (0-1000 ohms) to
enable me to measure it properly ?

Thanks

Scott, aka KBØFHP






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