I've been reading throught the Apollo 11 Flight Journals and was wondering how they were originally recorded and transcribed. It seems that they were painstakingly accurate down to the last second that something was said in terms of MET. I was honestly wondering how they got time-stamps down to seconds, are those just guesses or was even radio silence recorded, then reverse engineered later? Obviously the MP3 format had not existed, does anyone know what technologies were used to capture and record the transmissions to and from Apollo 11 in comparison to how we'd do it today?
EDIT: I was assuming it would be a device located at the command center, but because of the transmissions being recorded even when L.O.S.'d I was thinking I was incorrect. I was also assuming that having a recorder in both the CSM and LEM would be unneeded weight (audio is transcribed in both the LEM and CSM).
Here's a fun excerpt from them reading the "daily news" to the crew on Apollo 11 illustrating how detailed these logs actually were (note the accuracy of time-stamps):
072:34:02 McCandless: You might be interested in knowing, since you are already on the way, that a Houston astrologer, Ruby Graham, says that all the signs are right for your trip to the Moon. She says that Neil is clever, Mike has good judgment, and Buzz can work out intricate problems. She also says Neil tends to see the world through rose-colored glasses, but he is always ready to help the afflicted or distressed. Neil, you are also supposed to have, quote, intuition that enables you to interpret life with feeling, unquote. Buzz is to be very sociable and cannot bear to be alone in addition to having excellent critical ability. Since she didn't know at what hour Mike was born, she has decided that he either has the same attributes as Neil or he is inventive with an unconventional attitude that might seem eccentric to the unimaginative.
072:34:56 Haise: And last but not...
072:34:58 Collins: Who said all that?
072:35:00 McCandless: [Laughter] Ruby Graham, an astrologer here in Houston. Now we check with Flight Operations for all the signs for the mission, and then we, of course, had to make sure that everything was really all set. [Long pause.]
Another example of a line with EXTREME data density, I was wondering how they could've possibly kept all of these numbers correct in a transcript/recording in real-time:
072:53:54 Armstrong: Roger. LOI-1, SPS/G&N: 62710, plus 0.98, minus 0.19; 075:49:49.65; minus 2889.7, minus 0394.4, minus 0068.6; 358, 226, 347; 0169.2, plus 0061.0; 2917.3, 6:02, 2910.8; 31, 106.6, 35.8. GDC align, Vega and Deneb, 243, 183, 012. No ullage. Horizon in the hatch window 2 minutes before TIG. AOS with an LOI, 76:15:29; AOS without an LOI, 76:05:30. HA before the burn, 431.3; HP, minus 128.2. Say again LOS time.
It seems that even when not in contact with Huston (on the far side of the moon) the audio is still being both transcribed and recorded too:
[At 075:41:23, precisely when Houston predicted, the radio signal from Apollo 11 is lost.]
075:41:23 Aldrin (onboard): How soon are we going to...
075:41:24 Armstrong (onboard): [Garble] take 2.
075:41:25 Aldrin (onboard): 1 second early. Okay. Main Bus Ties...
075:41:28 Armstrong (onboard): Okay.
075:41:29 Collins (onboard): I'm going to turn my S-Band Volume down, so you can [garble].
075:41:33 Armstrong (onboard): Down Voice Backup.
075:41:39 Aldrin (onboard): Main Bus Tie A coming On. Have you got TVC Gimbal Drive - Pitch and Yaw to Auto, huh?