[RFI] Coaxial Choke

[Jim Brown]

The material in the ARRL Handbook is woefully out of date and quite inadequate. 
See http://audiosystemsgroup.com/RFI-Ham.pdf  for much more effective choke 
designs, with measured data to support them. 

73,

Jim Brown K9YC

>from the 2008 handbook

>Table 21.4
>Effective Choke (Current Baluns)
>Wind the indicated length of coaxial feed line into a coil (like a coil of rope) 
>and secure with electrical tape. The balun is most effective when the coil is 
>near the antenna. Lengths are not critical.

>Single Band (Very Effective)
>Freq  RG-213,RG-8       RG-58
>3.5   22 ft, 8 turns    20 ft, 6-8 turns
>7     22 ft, 10 turns   15 ft, 6 turns
>10    12 ft, 10 turns   10 ft, 7 turns
>14    10 ft, 4 turns    8 ft, 8 turns
>21    8 ft,  6-8 turns  6 ft, 8 turns
>28    6 ft,  6-8 turns  4 ft, 6-8 turns

>Multiple Band
>Freq    RG-8, 58, 59, 8X, 213
>3.5-30  10 ft,  7 turns
>3.5-10  18 ft,  9-10 turns
>14-30   8 ft,   6-7 turns

>-- 
>GB & 73
>KA5OAI
>Sam Morgan
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