RadioBanter - View Single Post - Putting a Ferrite Rod at the Far-End of a Random Wire Antenna ?

November 14th 04, 05:57 AM

On 13 Nov 2004 20:41:52 -0800, (RHF) wrote:

JK, RC and CM,

I want to Thank Each of You for your replies to this question.

Note: I am only talking about a SWL "Receive Only" Antenna here.

Hi OM,

As were the answers (with possibly one exception).

I suspect that may be one reason that this Far-End Loaded AM/MW
Coil may work is the fact that the RF Systems EMF Antenna is
'only' Sixteen Feet (16') Long; and the Two Inch to Three Inch
(2"-3") Ferrite Rod at the End of the Wire Antenna Element does
have some 'measurable effect' on improving the AM/MW Frequency
Band performance of such a short Antenna.
- Relative Size may be the Controlling Factor for this 'unique'
small Antenna

? ? Would this 'trick' work with a Larger {Longer} SWL Antenna ? ?

Let's approach this from the usual perspective. Many SWLrs posting
here already have the ferrite antenna in their receiver and come here
for a boost in signals. The fact that it is so easily accomplished by
the addition of that same 16 feet of random wire tossed across the
living room rug would suggest just how much contribution is found in
the ferrite antenna.

Let's put some numbers to it. With the ferrite antenna a DX station
comes in S3, replace it with the wire and it climbs to S7. So, if we
start with just the wire antenna with the same signal at S7, and
adding the ferrite to pump up da volume to S7+ would this be worth $95
to you? What if by simply adding 6" more wire to the 16 feet gave you
that same +?

As a product, it is incredibly cheesy to boot. Look at that clunky
pl259 at the end of rg174. C'mon now, are we talking about your
granddad's RCA Victor this sucker is going to plug into? That and the
lead-in is only 16 feet in its own right? How much profit would be
lost to give you a decent length of wire and lead-in?

My more specific point of interest would be in whether using a
Ferrite Rod with the Wire Antenna Element Wrapped as a AM/MW
Coil around it would have some meaningful effect on a Horizontal
Random Wire Antenna that was 75-100 Feet long.
- For a Horizontal Random Wire Antenna ?WHY? 'place' the
Ferrite Rod at the Far-End of the Wire Antenna Element ?
- Why not 'place' the Ferrite Rod near the Feed-Point-End ?
- Why not 'place' the Ferrite Rod near the Middle ?
- Why not 'place' the Ferrite Rod near the slightly Off-Center
38%/62% like a Windom ?

This at least suggests a more practicable study. Loading coils don't
do very much without some form of capacitance above them to draw the
current. Putting a coil at the top is a fruitless exercise. It may
offer to "tune" but it sure won't sing.

73's
Richard Clark, KB7QHC