This was apparently all I was ever able to make out.
The Columbia Conversation:
“This is Comm Station Epsilon IX, calling USS Columbia. Come in Columbia. Respond please.”
“This is Scout Columbia, Epsilon IX. Could you boost your transmission please? You’re reading… (unintelligible*)”
“This is Epsilon IX, Columbia. Am boosting output. How read you this?”
“Fine, Fine, Epsilon IX. Proceed with your transmission.”
“Scout Columbia NCC-621, to rendezvous with Scout Revere NCC-595 on stardate 7411.4. Further orders to be relayed at that time. Signed Commodore Probert, Starfleet. End of transmission.”
“Received and understood Epsilon IX. Thank you. Give my best to your commander.”
*The rest of this sentence is mostly unintelligible. It sounds something like, “You're reading four points below… blah blah blah.” or, "You're reading four points into the… blah blah blah.”
Dreadnought Entente transmissions:
The first male voice:
"This is Dreadnought Entente Calling. NCC-2120. Callling Comm Station, Epsilon IX. Come in."
Female voice immediately after his ends:
"Epsilon IX. This is Dreadnought Entente Calling. NCC-2120. Comm Station Epsilon IX. Come in."
(They are nearly identical, although I've never heard him say "Epsilon IX" at the beginning, and she doesn't appear to say "calling" the second time. Both pronounce the zero in 2120 as “oh.” Both tend to pause unusually long between "Comm Station" and "Episilon IX.")
The only other thing easily heard is "Long range shuttle Lakia" (or Lincoln, or something entirely different) Though is is part of a bigger message, and the Merrimac is apparently listed in this message (either by name or registry, or both). Those with good systems claim it is a message to the Merrimac from the shuttle about an intent to begin some sort of landing procedure or mission and to inform them of a delay in their scheduled meeting. The delay is to be explained upon their arrival. There appears to be a "Received your transmission" or, "Proceed with your mission" at the end as well.
That's all I have from that scene it seems.