Topband: Buffaloed by a bias tee

[Richard (Rick) Karlquist]

On 1/23/2014 10:45 AM, Pete Smith N4ZR wrote:

> capacitor..  Now all I have to do is to find a source of some
> appropriate chokes for the final tee, and my problems may be behind me.
> I was just looking at some Hammond chokes, no. 1532h - 100 uH, rated for
> maximum DC current of 500 ma., solenoid wound, self-resonant frequency
> of 12 MHz.  Sound reasonable?
>
> 73, Pete N4ZR

See:

http://www.vishay.com/docs/34013/ih.pdf

Here is a product line from Vishay (used to be Dale)
that gives you a lot of options.  Unfortunately, you
have to characterize them at RF yourself.  I have
used them many times for RF chokes and the RF performance
is acceptable.  What is especially good about these
is the really high DC rating.

In special purpose applications, I have tuned the
self resonance by peeling off turns.  The wire is
held on by glue that lets go fairly easily.  I
made channel 2 TV blocking filters this way.


Rick N6RK