[GreenKeys] Dual tape M28 TD's

[Eric Scace K3NA]

In the configurations that I was familiar with, a 
triple-headed TD had only two heads used for message tapes. 
  The third head contained a tape (often metal-mylar) that 
contained a series of channel numbers for the circuit that 
was being serviced; e.g.,
ABC figs 001 ltrs ABC figs 002 ltrs...

Some electromechanical stuff would run the channel numbering 
tape until a letters character was found, then switch over 
to run one of the message tape heads.  At the end of that 
tape, the logic would go back to the channel number tape for 
the next number, and then finally to the head holding the 
next message tape.

I have one of these still...

-- Eric K3NA

on 06 Feb 10 Fri 13:17 WA3FRP at aol.com said the following:
> Greg,
>  
> I think you are referencing the Multiple LXD Tape Reader.  
>  
> Here is what I have on this unit:
>  
> The Model 28 Multiple Transmitter-Distributor is an expanded version of the  
> standard, Teletype LXD tape reading unit.  Similar components are  
> incorporated into the multiple set, all driven by one motor. 
>  
> This unit translates 5 level punched tapes into serial line signals, and  
> sends them to one or more receiving locations.  Optional code reading  contacts 
> are available for parallel-wire output. 
>  
> When used with automatic message numbering systems, an optional "flip-flop"  
> feature makes it possible to number messages in the order in which they are  
> sent.
>  
> The reader's three heads may be operated at one time, feeding three  
> different locations simultaneously.  Each reader may also be operated  independently.
> 
>  
> Another method of operation is to have all three portions of the reader  
> sending data to one location.  This is accomplished by placing a different  
> message into each of the three heads of a reader equipped with "flip-flop"  action. 
> Thus, as the first potion of tape is completed, the second reader is  switched 
> into operation automatically.  When the end of that tape is  reached, the 
> third head goes into operation. 
>  
>  
> Physical Data:   Width 17 3/16 inches; Depth 14  1/2 inches; Height 6 1/2 
> inches; Weight 42 3/4 lb.
>  
> Speed 60, 75 or 100 WPM.  
>  
> Start, stop and free-wheeling positions on the control levers.
>  
> Electrical Data:  Clutch trip magnet - 115V AC; 120V  DC; 50V DC
>  
> Signaling -  5 level, 7.42 unit, start-stop either 0.020 or 0.060  amp
>  
> Motor - 115 V AC 60 cycle, 3600 RPM, synchronous
>  
> Terminals - Quick-disconnect, 36 terminal connect plug
> 
>  
> 73,
>  
> Russ WA3FRP
>  
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