If there is rf on the outside of the feed line then the feedline is a
part of the antenna SYSTEM and a part of the impedance presented to the
radio. If there is rf on the feedline then adding a ferrite snapped on
around the feedline will change antenna SYSTEM and thus the impedance
presented to the radio. The change may or may not be beneficial to the
radio and/or radiation efficiency.
If the feed line is not a part of the antenna system ( no currents on
the outside of the feed line ) then other things are more predictable.
AL, K0VM
On 6/20/2014 2:26 PM, David Cole wrote:
Hi,
I should have asked a different question... Any idea why the rig is
getting warmer than if no ferrite's...
Here is some more information...
A fellow wrote me off list asking for more info...
Antenna is on roof, and AC wiring is I am sure in attack area. About
three feet of coax between the tuner and radio. He is running 30 watts,
no grounds, all bonds are via coax, one ground to tuner. No balun on
the OCF...
I get that the OCF makes things very unbalanced, (he has no balun on
it), and I get that a single ferrite won't correct this, (he did no
winding), but why might the rig get warm? I thought I had a handle on
how this stuff was working, but for the life of me, I can't imagine why
the rig gets warm... It always sees a 1:1 because he is tuning it the
feedline to 1:1 as it feeds the rig...
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
|