Thread: Choke /BALUN
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Old June 4th 06, 05:37 AM posted to rec.radio.amateur.antenna
John Popelish
 
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Default Choke /BALUN

Jimmie D wrote:
I want needinfo on the type of cores do I need to use with RG58 and RG 214
to make a choke type BALUN at 2m. I am building a vertical dipole out of 1
inch al tubing. coax will pass through the bottom half othe dipole with the
sheild fastend at the middle of the bottom piece and cneter conductor
fastened to the top piece of al. Initial test indicate I have RF on the
shield and need some decoupling. Winding the coax into a coil certainly
helped but this has prevented me from placing the antenna in a fiberglass
tube the way I had planned.


For the RG58, each Steward HFB143064-300 (sorry for the ridiculous
link length):
http://www.steward.com/web_part_no.a...=HFB143064-300
provides about 180 ohms choke impedance.

Each slightly longer and in a lower frequency ferrite, 28B0591-200:
http://www.steward.com/web_part_no.a...rt=28B0591-200
provides about 500 ohms choke impedance.

For the RG214, each Steward HFB259128-100:
http://www.steward.com/web_part_no.a...=HFB259128-100
provides about 120 ohms of choke impedance.

Each 28B1020-100:
http://www.steward.com/web_part_no.a...rt=28B1020-100
provides about 300 ohms of choke impedance.

You will have to string these on the coax before terminating it.