Correctness of Your Approach

Yes, using an isolation transformer is generally the correct approach in this situation. It isolates the TV and other connected equipment from the ground potential difference, preventing current flow through the CATV line.

Additional Considerations



Ensure proper grounding

The power-line ground must be properly connected to the building's grounding system. This ensures that any excess current can be safely dissipated.

Verify transformer isolation

Test the isolation transformer using a multimeter to ensure that it is providing the required level of isolation.

Monitor TV performance

Observe the TV screen for any further issues with horizontal banding. If the problem persists, there may be additional electrical issues that need to be addressed.

Other Methods to Deal with Ground Potential Differences



Ground bonding

Connect the TV ground to the CATV shield and power-line ground using a bonding strap or jumper wire. This method equalizes the ground potentials, but it may not be suitable for all installations.

Common-mode choke

Install a common-mode choke on the CATV line. This device suppresses common-mode noise and can reduce the impact of ground potential differences.

Ground loop isolator

Use a ground loop isolator to prevent current from flowing through the CATV line. This device typically uses transformers or optical isolation to isolate the signals.

Recommendation:

In most cases, using an isolation transformer is the most effective and safe method to deal with ground potential differences in this type of installation. It provides isolation while maintaining signal integrity. Flag for review