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Old August 5th 06, 05:06 PM posted to rec.radio.amateur.antenna
John Popelish John Popelish is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 36
Default Rule of Thumb for coax chokes

Will wrote:
That is neet. Now I just got to figure a choke of RG8X at 146mhz to
keep the RF from comming back down the outside of the coax cable from
the J pole.
The VSWR is realy good at 1:1.1, and it talks realy well.

What about ferrite beads/chokes over the coax instead of the coil of
coax cable?


Digikey carries a pretty broad line of Steward long form ferrite bead
cores. You can check the specifications at http://www.steward.com/

For instance, core HFB143064-300 has an impedance of about 180 ohms at
146 MHz. Type HF is their highest frequency material.

Core 28B0562-200 (same size in the lower frequency, 28 material)
produces an impedance of about 360 ohms per core.

I think both of these would fit over RG8X and are about an inch and an
eighth long.