Hi Svend,
Yes. Use a lot of #43 clamp-on cores. Buy the longest ones that fit the
cable. Study the data sheet and aim for at least 1K ohms. More is better. :)
On Tue,3/14/2017 11:08 AM, Svend Spanget wrote:
Hi Jim.
Do you have a recommendation for an effektive choke for 144 MHz?
VY 73 de Svend, OZ7UV
Den 14. mar. 2017 18.19 skrev "Jim Brown" <jim@audiosystemsgroup.com
<mailto:jim@audiosystemsgroup.com>>:
On Tue,3/14/2017 12:41 AM, Máximo EA1DDO_HK1H wrote:
Same question in a different way is; Is the current choke
forcing to balance differential currents?
Hello Maximo,
An effective common mode choke forces current to near zero at the
point where it is placed. IF it placed at the feedpoint, it will
force current in the sides of the antenna to be equal AT THE
FEEDPOINT. In effect, it disconnects the feedline from the antenna
as an element of the antenna.
If the same choke is placed near the shack, the feedline IS part
of the antenna, with it's electrical length equal to its physical
length, with the choke forcing the common mode current to near
zero at the point where it is placed in the feedline.
By "effective," I mean a choke that has a very high common mode
resistive impedance at the operating frequency.
73, Jim K9YC
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