[TowerTalk] Toroid Core Material Selection

[Keith Dutson]

Thanks to all who offered help.  Seems mix 31 is the hands down favorite.
The only thing I can find on the 'net are beads offered by DX Engineering.
I suppose using beads rather than toroids will block the RF sufficiently.

BTW, my homebrew project is a pair of relays to switch two antenna
connections in the shack.  The design bandwidth for these two antenna
switches is 1.8 to 450 MHz.  A friend with a spectrum analyzer measured some
crosstalk between the SO239 connecters and suggested the toroids be inserted
in the dc lines to each relay to improve isolation.  Insertion loss was also
measured to be about 3 dB at 500MHz.  This is not acceptable so I am looking
for better relays.
 
Keith NM5G

-----Original Message-----
From: towertalk-bounces at contesting.com
[mailto:towertalk-bounces at contesting.com] On Behalf Of Keith Dutson
Sent: Monday, March 21, 2005 2:27 PM
To: towertalk at contesting.com
Subject: [TowerTalk] Toroid Core Material Selection

I want to block RF from possibly feeding back into a 12 volt DC power
supply.  What is the best material for this available in a small toroid?
Will a one-turn winding be sufficient?  Thanks in advance for your help.

Keith NM5G