B737-700
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 166; Flight Crew Type 15000
Flight Deck / Cabin / Aircraft Event Illness / Injury; Inflight Event / Encounter Other / Unknown
General None Reported / Taken
Airspace Structure; Aircraft
During cruise flight at FL390 and approximately 160 NM southeast of JAX; we needed to contact [Medical Services].  The 'Enroute Radio Frequencies' section of our Dispatch Release indicated Frequency 130.70 departing FLL; and 131.17 at LENDS intersection.  We had not yet reached LENDS intersection.  Trying frequency 130.70 had no response; even with the squelch off.  On 131.17 we could hear radio but the voice quality was weak with static.  [Medical Services] on 131.17 was un-useable.  There was a severe echo and distortion of their transmissions.  However; Company Dispatch and [Medical Services] said they could hear us loud and clear.  We finally reached [Medical Services] via JAX Operations on 131.70.  This process took about 12 minutes to establish useable communications.Communications capability needs to be improved using existing technology.  This type of delay could require Pilots to make divert decisions without the benefit of [Medical Services] advice if the medical emergency was time critical.
A B737 Captain experiences difficulties contacting Medical Services on the listed Commercial Radio frequencies over the Atlantic Ocean east of MLB. Eventually a usable frequency is found to discuss the condition of an ill passenger.