In 1925 and 1926, Blumlein and John Percy Johns designed an improved form of loading coil which reduced loss and crosstalk in long-distance telephone lines.
22.
Conversely, it is possible to analyse a transmission line with lumped components, such as one utilising loading coils, in terms of an image impedance filter.
23.
:I believe that loading coils were an earlier attempt at reducing distortion on such cables . talk ) 13 : 49, 18 December 2012 ( UTC)
24.
In this frequency range their realization is very difficult because of the very high voltages that occur in the huge tuned loading coils that are used in the antenna feed.
25.
Lower power transmitters often use electrically short quarter wave monopoles such as inverted-L or T antennas, which are brought into resonance with a loading coil at their base.
26.
For frequencies below longwave, masts are electrically enlarged by loading coils or capacity hats on the top, because masts of even quarter wavelength would be too high to be practical.
27.
Since an antenna which had been too short now appears as if it were resonant, the addition of the loading coil is sometimes referred to as " electrically lengthening " the antenna.
28.
The phenomenon of cutoff whereby frequencies above the cutoff frequency are not transmitted is an undesirable side effect of loading coils ( although it proved highly useful in the development of filters ).
29.
With loading coils of exactly the right inductance, neither capacitance nor inductance dominate : the response is flat, waveforms are undistorted and the characteristic impedance is resistive up to the cutoff frequency.
30.
This is not identical to a distributed loading, the difference being that with loading coils there is distortionless transmission up to a definite cut-off frequency beyond which the attenuation increases rapidly.
