Switcher,
AM/MW Loop Antenna - Inductive Coupling -vice- Resistor Spoiler
http://groups.yahoo.com/group/Shortw...a/message/9407
To some degree all Circuits are L+C+R
- - - Although anyone of the three may not be significant
enough to factor into the Circuit Design parameters.
- - - Hence an AM/MW Loop Antenna is simply presented
as an L+C Circuit.
"IF" you were to use a Resistor in the Circuit of an
AM/MW Loop Antenna it would be 'because' the Radio
that you were using it with was being OverLoaded by
the Signal from the Loop Antenna.
You could simply achieve the same thing by varying the
AM/MW Loop Antenna 'coupling' with the Radio -by- Moving
the Loop Antenna nearer-to -or- farther-away from the Radio.
AM/MW LOOP ANTENNA COUPLING :
* The Coil of the external AM/MW Loop Antenna
is an Inductor {RF Transformer Coil}
* The Coil of the Radio's internal AM/MW Antenna
is an Inductor {RF Transformer Coil}
* Together the Two Coils form an RF Transformer
Moving the Two Coils and changing their relationship
to each other varies the "Coupling" between them.
THINGS TO READ :
READ - AM/MW DXing = Your Radio + Lazy Susan + Loop Antenna
for better AM/MW Band Reception and DXing with an AM Radio.
http://groups.yahoo.com/group/Shortw...a/message/1787
http://groups.yahoo.com/group/Shortw...a/message/1811
READ - Using the Built-in WHIP Antenna for better AM/MW Band
Reception and DXing with an AM Radio.
http://groups.yahoo.com/group/Shortw...na/message/875
READ - AM/MW Radio Reception : Whip Antenna Up? -or- Down?
for better AM/MW Band Reception and DXing with an AM Radio.
http://groups.yahoo.com/group/Shortw...a/message/1105
READ - AM/MW Random Wire Antenna Tuner using a AM/MW Loop
Antenna for better AM/MW Band Reception and DXing with an AM Radio.
http://groups.yahoo.com/group/Shortw...a/message/1150
READ - "HOW TO USE" a AM/MW Loop Antenna with a 'portable'
AM/FM Shortwave for better AM/MW Band Reception and DXing
with an AM Radio.
http://groups.yahoo.com/group/Shortw...a/message/1865
READ - For Improved AM/MW DXing
- Think Loop Antenna as a Coupler Tuner for better
AM/MW Band Reception and DXing with an AM Radio.
http://groups.yahoo.com/group/Shortw...a/message/2240
http://groups.yahoo.com/group/Shortw...a/message/2272
http://groups.yahoo.com/group/Shortw...a/message/2769
READ - Two 'basic' optional In-Door Antennas for better
AM/MW Band and FM Band using a 'portable' AM/FM Radio.
http://groups.yahoo.com/group/Shortw...a/message/2936
READ - Long "LoopStick" Antenna for AM/MW/BCB DXing
-by- Bill Bowden
http://groups.yahoo.com/group/Shortw...a/message/3075
http://groups.yahoo.com/group/Shortw...a/message/3100
The "L O N G" -Liner- {Skinny} Loop Antenna for better
AM/MW Band Reception and DXing with an AM Radio.
READ - Every Grundig Satellit 800 M Owner's Dream...
a 21" Lazy Susan for better AM/MW Band Reception and
AM/MW DXing
)
http://groups.yahoo.com/group/Shortw...a/message/4406
READ - Setting-Up the Sony ICF-SW7600GR with a Loop Antenna
on a Lazy Susan for better AM/MW Band Reception and DXing.
http://groups.yahoo.com/group/Shortw...a/message/5886
RESISTOR AS A SPOILER IN AN AM/MW LOOP ANTENNA CIRCUIT :
-However- If you must use a Resistor in the Circuit of the
AM/MW Loop Antenna - Consider using a Series 1000 Ohm (1K)
Potentiometer (Pot) - So that you could adjust and fine-tune
the Circuit to achieve the Maximum Signal without OverLoading
the Radio. Hook the "Pot" up with the two ends connected
together and the Center Wiper as teh other end of the
Resistance Element of the Circuit. With the Wipper at either
end the Pot is out of the Circuit. As the Wiper is moved
from one of the ends to the Center of the Pot the amount
of Resistance in the Circuit 'increases' and the RF Signal
{EMF Field} of the Loop Antenna is Decreased. Wiring-Up
the Pot this way makes the Resistance Curve non-liner from
"0" to 500 Ohms sort of more like an Audio Taper Pot.
and now you know - iane ~ RHF