Tree wrote:
> On Tue, Apr 14, 2009 at 05:18:55PM -0500, Sam Morgan wrote:
>
>> Does the common coaxial choke do the same thing as the high dollar ones?
>> Particularly if you are only running 100w? (160m-10m)
>> I forget the length now, but it's in the handbooks,
>> just looked 10 foot of RG-8, 58, 59, 8X, 213 in a 7 turn loop.
>
> Depends on the frequency you are dealing with. You need probably more
> turns for lower frequencies (like 160-40 meters).
>
> Tree N6TR
>
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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