An Antenna trap is a parallel LC circuit that has one input
and one output terminal. You can make a resonant trap
with series LC that also has one in and one out..

Is it possible to make a two terminal network lowpass filter?

Something like a sharp rolloff RF choke?

Thanks
KL7R

kl7r wrote:
An Antenna trap is a parallel LC circuit that has one input
and one output terminal. You can make a resonant trap
with series LC that also has one in and one out..

Is it possible to make a two terminal network lowpass filter?

Something like a sharp rolloff RF choke?

Thanks
KL7R

You must remember that parallel and series resonant circuits in
antennas are not really two terminal networks. There has to be ground,
common, earth or whatever and it is common to both the input and
output.
A lowpass filter is realized by a single inductor whose impedance
increases, with increasing frequency. Highpass with a capacitor-the
sharpness of the rolloff is dependent on the Q of the passive devices.
That is it in a nutshell.
There are other factors that enter into this if the devices are used
in antennas. There are several hundred posts to chose from on the
antenna forum.

73 Gary N4AST