For anyone contemplating using a direct coax connection to an antenna....
When coax is directly connected to a balanced antenna, a series of
choke ferrites can minimize perturbations to the antenna pattern....
they ALSO reduce pickup of locally generated noise along the coax:
This is probably more of a problem at VHF than UHF....
Choice of Ferrite material must be appropriate for operating freq, which
explains why they are popular for narrow band Ham radio bands but
NOT so much for wide VHF & UHF TV bands. Analysis is also difficult:
[The latter is a current balun that wraps coax around a Ferrite core.]
Ferrite Core kits are usually available from Ham Radio enthusiasts:
Hi-VHF TV Band is closest to 144 MHz Ham band.
UHF TV Band is between 420 MHz and 920 MHz Ham bands.
Where you will see that it takes MULTIPLE Ferrite choke cores
on the coax to provide the desired amount of impedance.
On-line catalog and an earlier *.pdf file can be found here:
Or use one of the several quarter & half wavelength Baluns: