On 2006-02-11, Ken C wrote:

Well, NASA uses roger beep with its astronauts

Actually NASA used "quindar tones" which are in-band signalling to
activate ground transmitters. Those beeps were removed by a notch
filter and never made it into the uplink.

--
Ben Jackson

http://www.ben.com/

The question to seek is WHY are they there?

The "courtesy tones" serve a purpose (yes that is a funny name and I don't
know where it started, but)...to tell when the timer is reset.
73, Steve, K9DCI

"Ken C" wrote in message
...
On Fri, 10 Feb 2006 15:15:25 -0800, "Caveat Lector"
wrote:
Hi Ken -- ignore the nasty replies

I always ignore the crackpots; most have no lives and nothing to say
of value.

Well, NASA uses roger beep with its astronauts and ham repeaters use
them all the time, but call them courtesy tones. So I see no problem
with experimenting on SSB, especially with folks I know who have no
objection. Especially if the tone if not loud or extravagant.

In spite of my agreement with most of the flames thrown at you about this,
there are certain applications where "curtesy tone" is warranted - as few as
they may be.

So that out of the way, often the RX is used to enable/mute the audio If the
RX is pulled low, it enables the audio path to the audio output. If open it
will mute.


"Ken C" wrote in message
...
I am trying to adapt a CB "roger beep" mic for ham radio and there is
some odd terminology for CB mic wiring.

The CB'ers call "PTT" "transmit (TX)"

They call "audio-out" "audio" (not too bad)

They have a separate line for "receive (RX)" which some call "receive
control." What is that for? Anyone know? By testing, I know it is
not for a speaker in the mic. It shows 6 ohms to ground.

Ken KC2JDY