[time-nuts] purpose of time of day display units

[Robert Atkinson]

One must remember the original use of these displays was displaying IRIG time either distributed from a master clock, locally generated or from a recording (tape) They long predate GPS. There are more sophisticated units that include controls for the tape recorder so you could auto search to a certain time. Multiple displays could be used for locally generated time, time received from a remote site by fixed line or radio and time from data or video recorders.I have a number of them and one sits above my GPStar as the LCD on the GPStar is hard to read from across the workshop and it lets me have time available while showing timing or satellite  status on the GPS. Just picked up 3 more (RAPCO 104 anyone have a manual for these) at the weekend.
Robert G8RPI.

      From: Bob Bownes <bownes at gmail.com>
 To: Discussion of precise time and frequency measurement <time-nuts at febo.com> 
 Sent: Sunday, 22 January 2017, 18:33
 Subject: Re: [time-nuts] purpose of time of day display units
   

#5) Everyone likes blinkenlights. 



> On Jan 22, 2017, at 08:55, jimlux <jimlux at earthlink.net> wrote:
> 
>> On 1/21/17 10:31 PM, Ruslan Nabioullin wrote:
>> Hi, looking at pictures of various time metrology equipment setups for
>> best practices and inspiration, I have commonly seen time of day display
>> unit(s) installed in racks containing processing or time transfer
>> equipment, e.g.,
>> http://www.xyht.com/wp-content/uploads/2015/05/Powers_Master_Clock.jpg.
>> All that these units do is merely display the time of day and sometimes
>> the date, typically by means of seven segment LED displays, of the time
>> code inputted to them (typically IRIG-B, I'm guessing).
> 
> There's a few reasons I can think of:
> 1) the display is also a distribution amplifier of some sort - one time source going into rack, distributed to things in the rack (or the next rack)
> 
> 2) as phk commented, it lets you know that your time code isn't broken (i.e. someone got in behind the rack and disconnected the wrong cable)
> 
> 3) It's a crude visual check - your eye/brain is pretty good at catching a change in the pattern of blinky lights.  IN this situation, you'd expect all the displays to change simultaneously.
> 
> 4) the equipment configuration "just growed" from a collection of smaller ones, each with its own display.
> 
> We put displays like this in all of our ground support equipment (GSE) racks when doing spacecraft or subsystem tests, mostly for reason #2 and #4.
> 
> You might have a GSE rack or two in the lab when you're building up the subsystem.  Someone else's subsystem has their rack, also with a timecode display.  When you bring the two subsystems together for integration, you bring the racks with them, and it's not worth it to reconfigure.
> 
> 
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.