bill@berlioz (Bill Bencze) (07/22/89)
This is a question that always has been bugging me and I have never been given a good answer: What function do the ever present "beeps" serve in the voice communication between spacecraft and the ground? These are the 1~3 kHz beeps of about a half second in duration which seem to occur at random duning the transmissions. Are they electronic "Over" signals automatically sent at the end of a transmission or some other type of timing signal. Please satisfy my curiosity!!! Bill Bencze. National Semiconductor Corp. bill@bach.nsc.com.
masticol@athos.rutgers.edu (Steve Masticola) (07/22/89)
Bill Bencze writes:
] What function do the ever present "beeps" serve in the voice
] communication between spacecraft and the ground? These are the
] 1~3 kHz beeps of about a half second in duration which seem to
] occur at random duning the transmissions. Are they electronic
] "Over" signals automatically sent at the end of a transmission or
] some other type of timing signal.
They're not random. I believe they're sent when the speaking party's
VOX times out (after about a half second of silence).
- Steve (masticol@athos.rutgers.edu)johnl@gronk.UUCP (John Limpert) (07/25/89)
In article <474@bach.nsc.com> bill@berlioz (Bill Bencze) writes: >What function do the ever present "beeps" serve in the voice >communication between spacecraft and the ground? These are the >1~3 kHz beeps of about a half second in duration which seem to >occur at random duning the transmissions. Are they electronic >"Over" signals automatically sent at the end of a transmission or >some other type of timing signal. The beeps are called "QUINDAR tones". I believe QUINDAR was the manufacturer of the equipment that decodes the tones. The tones are used to control transmit/receive switching in the air-to-ground voice communications equipment. Two tones are used, one when a transmission begins, the other when it ends. -- John Limpert johnl@gronk.UUCP uunet!n3dmc!gronk!johnl