[Elecraft] K3 & Common mode

[Dave G4AON]

8 turns on the stacked cores appear to give higher impedance on the low
bands compared to typical chokes fitted to other transceiver power
leads. Here in Europe the Kenwood TS-480SAT includes a TDK ZCAT3035-1330
choke which with 2 turns of the K3 lead (maximum that will fit) would
only give around 90 Ohms impedance compared to 820 Ohms for the
FT-240-43 with 8 turns, at 1.9 MHz.

An on-line calculator for various chokes is at: http://toroids.info/
(the TDK choke info is at: www.tdk.co.jp/tefe02/e9a15_zcat.pdf)

73 Dave, G4AON
K3/100 #80 with thankfully no broadcast breakthrough here
======================
80 WAS poor and 160 unusable until i put a common mode choc in DC cable.
i got my best result with 8 turns on 4x FT-240-43 stacked.

Is anyone with experience in chocs on DC line ?

73 Jeff F6AOJ