Re: How long the ferrite rod?

Rich Grise wrote: 
On Sun, 15 May 2005 19:35:05 +0100, Richard wrote:


Hi.

I'm wanting to exchange "air cored"  frame aerials for ferrite rods, for
the medium waveband (Broadcast band).

The ferrite rods are 10mm dia, and the MW coil for it is 35mm long, I
think about 90 turns. Now, how long should the ferrire rods be do you
think? The thing is, I've got some fairly long rods (200mm long) and I'm
thinking should I cut the rods so they are say 100mm long or even 66.66mm
long. The point is, does it matter that much how long the ferite rod is?
Could I in fact use a 66.66mm rod and it would be no better or worse than
a 100mm rod?

Also, how do you cut a ferrite rod? TIA. 


If it's powdered iron, you can cut it with a diamond saw. If it's
ferrite, you probably can't cut it, but there's a possibility you
could score it with a triangular file and snap it, like glass
tubing.

But unless you need to shorten it for reasons other than reception quality, there is little reason to shorten it. The only reason radios don't come with foot long ferrite rods is cost and overall unit miniaturization.
.

Relevant Pages

  • Re: Ferrite rod antennas
    ... In the "ARRL Antenna Compendium, Vol. 6", there is an article ... describing a tuned, ferrite rod, magnetic receiving loop antenna - ... THE author glues ferrite rods together exactly as you propose. ... Gluing them together is a bad idea as you can not control the gap ...
    (rec.radio.shortwave)
  • Re: Ferrite rod antennas
    ... MW and 160meter band. ... In the "ARRL Antenna Compendium, Vol. 6", there is an article ... describing a tuned, ferrite rod, magnetic receiving loop antenna - ... THE author glues ferrite rods together exactly as you propose. ...
    (rec.radio.shortwave)
  • Ferrite rod antennas
    ... I am wondering if a large ferrite rod would be good antenna for maybe ... MW and 160meter band. ... Would there be an advantage to using a few rods glued ...
    (rec.radio.shortwave)