[TowerTalk] Fair rite materials for choke baluns

[Jim Thomson]

Date: Sun, 3 Jul 2016 16:49:21 -0700
From: Jim Brown <jim at audiosystemsgroup.com>
To: towertalk at contesting.com
Subject: Re: [TowerTalk] Fair rite materials for choke baluns

I didn't find this part in the Fair-Rite catalog because the assigned 
part number is for an inductive component, not for suppression. Many 
ferrite materials are useful as inductive components at lower 
frequencies and as suppression components at higher frequencies, so your 
measurements are not surprising given the material specs (see p 11 in 
the 17th edition of the Fair-Rite catalog).

BUT -- Fair-Rite controls specs based on their intended use, so 
inductive components are controlled for inductance, but NOT for loss 
impedance, and suppression components are controlled for suppression 
impedance and not for inductance. For example -- you can buy a #43 
2.4-in o.d. toroid controlled for impedance as Fair-Rite 2643803802. The 
same size #43 toroid controlled for inductance is 5943003801.

73, Jim K9YC

##  Ok, so the type 31  2.4 core we should be using for CM chokes is the 
toroid controlled for impedance... PN  2643803802    ?? 

## Good thing u mentioned the type 31 core  comes in 2 x versions.  I wonder
how many folks have ordered the wrong part number in error ?  

Jim   VE7RF