The radio stations are all transmitted from studios in Doncaster and between them attract a weekly audience of more than 200,000 listeners.
The £50,000 loan is providing the business with the capital for a transmission system and installation in replacement of paying lease costs for a transmitter. The new transmitter site is located in the centre of Doncaster.
The four Yorkshire stations are part of the Lincs FM Group which also operates other local stations in Hull and Lincoln.
Finance Yorkshire has previously supported Trax FM to improve its studio spaces, facilitating the move to modernise the studios and update equipment.
Group chief executive Michael Betton said: “Having the transmitter under our control is much better and will enable us to further improve the quality of our programming and services to the local area.
“We believe radio, and especially local radio, has a fantastic future – it’s very compatible with modern day life and it performs a key role in cementing local communities.
“We provide a really local service which results in listeners having great enthusiasm for the area in which they live.”
Finance Yorkshire’s David Ward said: “Since its launch in September 1999, Trax FM has gone from strength to strength, driven by a team which is passionate about the service it can provide to local communities.
“With our support, Trax FM has the ambition and ability to attract additional commercial interest and further grow its audience share.”