RadioBanter - View Single Post - If Amloop is LC circuit, what about RLC circuit ??

May 7th 06, 08:43 PM posted to rec.radio.shortwave,rec.radio.amateur.antenna

On 6 May 2006 13:41:51 -0700, wrote:

The lower Q makes the LC less selective. For a tuned loop, it is not a
good idea to introduce resistance.

switcher wrote:
a damped LC ???
Does it make sense to introduce a R in the LC circuit and use it as
antenna ??
Does it change eg the Q ??? etc ...
It certainly does. One of the ways to calculate Q is
Resistance/Reactance. By definition, increasing resistance will lower
Q.

Q is also the bandwidth/frequency at the point the signal is down to
half peak.

I have tried to put formula's here
(look if they are right !
freq_low=Math.sqrt(1/(inductance*cap_high) - (resistance * resistance )
/ (4 *inductance *inductance))/(2*Math.PI)
freq_high=Math.sqrt(1/(inductance*cap_low) - (resistance * resistance )
/ (4 *inductance *inductance))/(2*Math.PI)

OK ???
)
http://users.fulladsl.be/spb13810/amlooprlc.htm

A high R seems to lower the low freq, that's interesting ...

original formula for LC circuits: (put R = 0 in previous, and you should
get the same ....)

http://users.fulladsl.be/spb13810/amloop.htm

--
een appeltje te schillen met http://applefaulty.be
http://users.fulladsl.be/spb13810/bwnl.htm
Breng je iMac G5 terug (ik wil binnen 2 jaar geen defecte 2de hands Apple kopen)
http://www.apple.com/nl/support/imac...ensionprogram/