I was under the impression that that particular sound, the one NASA used or maybe still uses in their communication's to manned space missions was where it originated. I could be wrong. IDK.
I don't mind a short RB at the end of a transmission, especially when there's a lot of traffic. I think it makes sense. I do use it while I'm on 11m AM. I would never use it on the Ham bands just because they (we) frown on it, but used in the proper manner I don't know why it's not accepted.
The original "beeps" NASA used were called Quindar tones and were NOT used like roger beeps are today. They were used for automated switching of transmission links.
Quindar tones - Wikipedia, the free encyclopedia
The need for Quindar tones
For Mission Control
(in Houston, Texas
) to stay in continuous contact with the astronauts as they traveled to and from the Moon, NASA
used several tracking stations
around the world, switching from one to the next as the planet turned. Dedicated telephone lines (a very expensive measure at the time) connected these stations to Houston. NASA had the option to build two separate systems for operating the transmitters - one to carry the audio from the CAPCOM
and another to carry the control signal for the PTT button (out-of-band signaling
) - but instead chose to combine these two systems together into a single system to reduce the operating cost of the network.
The same system was used in Project Gemini
and was still in use with half duplex UHF Space Shuttle
communications for transmitter RF keying.
With modern digital communication systems, Quindar tones are no longer necessary because a single communication line (such as a fiber optic cable) can simultaneously carry multiple communication channels.
Implementation of Quindar tones
The "intro tone", a 250 millisecond tone at 2,525 hertz, followed by a 250ms 2,475Hz "outro tone".
The Quindar system, named after its manufacturer, used two tones, both being pure sine waves that were 250ms long. The "intro tone" was generated at 2,525 Hz and signaled the "key down" keypress of the PTT button and unmuted the audio. The "outro tone" was slightly lower at 2,475 Hz and signaled the release of the PTT button and muted the audio. The two tones were generated by special equipment located at Mission Control, and they were decoded by detectors located at the various tracking stations.
The selection of the tones allowed them to travel in the same passband
as a human voice
, which has a range from roughly 300 Hz to 3,000 Hz.
Common misconceptions about Quindar tones
Two common misconceptions surround Quindar tones. The first is that one tone came from Earth
and the other from the transmitters used by the astronauts
while in space. This confusion exists because many ground-to-space transmissions were initiated by Mission Control and responded to by the astronauts. In this sequence, the CapCom would press the PTT, which would send the intro tone, and then speak. When finished speaking, the CapCom would release the PTT, which would send the outro tone, and the astronauts would respond to Mission Control. Therefore, those transmissions would consist of a "beep" (PTT press) followed by Houston talking, then another "beep" (PTT release) and finally the voice of the astronauts.
Another misconception about Quindar tones is that they were designed to signal the end of a transmission, similar to a courtesy tone
used on many half-duplex
. Although the astronauts may have secondarily used the Quindar outro tone to know when the CAPCOM had started/stopped speaking,
no equivalent existed for Mission Control because the astronauts keyed their transmissions locally (inside the spacecraft) using either a PTT or VOX
, neither of which required Quindar tones. Additionally, separate radio frequencies
allowed both Houston and the astronauts to talk simultaneously if they wished and thereby made a courtesy tone as a way to minimize the possibility of both of them speaking at the same time unnecessary.