- Yes - Basically the 300 Ohm to 75 Ohm
-TV type Matching Transformer is a Balun.
-
- iane ~ RHF

And... yes some Shortwave Listeners (SWLs) have made a
very low cost and basic Shortwave Listening (SWL) Antenna
from TV type Parts :

1 - Wire Antenna Element - Using 300 Ohm Twin Lead.

Configured as {Shaped Like} :
* Dipole Antenna with Two Equal 50% / 50% Arms
* Windom Antenna with a Long 62% Arm and Short 38% Arm.
* Loop Antenna and wired as either a Series Two Turn Loop
-or- a Parallel Two {Twin} Wire Loop.
* Horizontal {Flat} Antenna
* Inverted "L" Antenna with an Up-Leg 33% and Out-Arm 67%
- - - All of these Antennas are for the most part built to fill the
Avaliable Space and thus are simply Random Wire Antennas.

2 - Balun - Using a 300 Ohm to 75 Ohm TV type
Matching Transformer.

3 - Feed-in-Line - Using 75 Ohm Coax Cable with "F"
Connectors as the Antenna's feed-in-line.

4 - Using an "F" Connector to PL-259 Plug Adapter to connect
the 75 Ohm Coax Cable to the Shortwave Radio's SO-239 Jack.
-or- Using a second TV type 75 Ohm to 300 Ohm Matching
Transformer to connect the 75 Ohm Coax Cable to the Shortwave
Radio's Twin {HI-Z} Terminals.

yes it is that simple - iane ~ RHF