The MFJ 4116
Bias Tee DC Power Injector.
Send up to 1 Amp/DC 50 Volts through coax feedline to power your electronic equipment. Use with your automatic tuner, remote antenna switch , antenna relay box etc. without running separate cables. To inject and to retrieve DC power use MFJ 4116 on each end of the coax (MFJ 4116P
MFJ 4116 covers all HF bands and six meters.