We have been using the Home Phone like you for several years now both at home and in our TC. We do have a corded cradle phone in the TC but use the cordless in the cab of the truck.
RLS7201 wrote:
You might try a Ferrite noise filter on the ground lines.
Cheap and easy to try. The more passes you make throught the filter, the better it works.
We had a simular issue with a 12 volt Blue Ray player and our 12 volt TV. The Ferrite filter on the ground wires fixed our problem.
We also use a Verizon Home Phone Connect. Both at home and in the RV, using the RV batteries and a cradel phone when on the road. Best deal in town.
Ferrite Filters
Richard