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Could you post a pic of your set up for this measurement,
I'd like to test some chokes and I think jig layout is very important to avoid
capacitive pick up.
----- Original Message -----
Sent: Saturday, March 11, 2017 8:25
Subject: Re: [CrossCountryWireless]
Inverted U terminated low noise antenna
I've found a graph relating choking impedance to common mode attenuation in
a presentation ChokeCurrentBalun.pdf by Jacques Audet, VE2AZX.
In this graph 10 dB of attenuation equates to 100 ohms, 20 dB 1000 ohms and
40 dB 10000 ohms.
A figure of 5000 ohms is 33 dB.
The 9:1 current balun common mode rejection figure up to 30 MHz is >40
dB so this would give a figure of >10000 ohms.
The attenuation at 50 MHz is 32 dB, this would give a figure of 2500