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[TowerTalk] Type 73 beads, W2DU balun.

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Subject: [TowerTalk] Type 73 beads, W2DU balun.
From: "Jim Thomson" <jim.thom@telus.net>
Date: Tue, 9 Dec 2014 08:02:15 -0800
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Here is something interesting.  The type 73 beads used in the W2DU balun are pn 
2673002402  per page 26 of the K9YC tutorial. 
Each bead is .380 OD  x .197 ID  x .190 long.   Each bead weighs a mere 1.2 
grams.   50 beads are used...for a total length of  9.5 inchs.
Total weight is 60 grams...   or .132 lb.   His experimental design used 300 of 
em.... or  360 grams =  .793 lb, and 57 inchs long. .  

The type 31/43 beads that slide over 213-U  are    1.020 OD  x.505 ID  x 1.125 
long...and weigh in at a hefty 55 grams each.   The same 9.5
inchs long of  the bigger beads would weigh 1.02 lb. 

Big difference between .132 lb   and 1.02 lb ...as in 7.7 times heavier..for 
the same length.    More thermal mass too. 
Just an observation as I have not noticed the weights of the various beads 
before.... nor the 2.4 inch od toroids, which
weigh in at 118 grams.   One 2.4 inch toroid  weighs the same as  just 2 of the 
large beads. 

Jim  VE7RF

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