[GreenKeys] Torn Tape Relay - waterfall

[Duncan Brown]

Speaking of Torn-Tape Relay stations, did any of you ex-comm center 
people remember using/seeing Teletype Corp. "waterfall" units in the 
Torn-Tape areas?

The AWA Museum just received an almost "new on the pallet", four 
printer, waterfall unit, thanks to Jack, K2TTY (SK) & Tom, WB2TTY.  Jack 
found it "new on the pallet" in a warehouse in Patterson, NJ in 2003, 
and Tom had been keeping it at his house when Jack was moving around the 
country. Teletype stopped production of the M28 line at the end of 1981, 
so this unit was sitting in a warehouse for over 20 years!

Tom & I, with some help from our XYLs, were able to get the unit out of 
Tom's upstairs and into the AWA Suburban with out too much trouble. (Tom 
had taken the four printer shelves out previously. The cabinet & 
printers filled the Suburban.)  It is now in the Museum spitting out 4 
copies of QBFs at 100wpm.




All the printers in this unit have "TT-386/UG" labels on them, though 
there is no military ID label on the cabinet (or holes where a label 
might have been).

The printers have been modified for TEMPEST: Shielded signal lines were 
run to each printer and the selector magnets of each printer are 
shielded! This unit may have been an AN/UGR-10, which was a "Model 28 
Low Level Multiple Page Printer Monitor Group" with MIL-STD-188B six 
volt polar interface. Unfortunately the original loop supplies and 
low-level selector magnet drivers are no longer in the cabinet. Either 
they were never there, or Jack had removed them.


Most of the pictures I've seen of waterfalls have been Navy 
installations and they seem to be typically located next to tape-relay 
equipment. eg: USS IOWA http://www.navy-radio.com/ships/bb61/DSC02044.JPG
On the transmit side of a tape relay system, each outgoing tape reader 
always has a "monitor" which records the transmitted message. This 
monitor is normally a reperforator that includes a take-up reel for the 
punched tape. This provides a record of what was actually transmitted. 
(There are 6 monitor reperfs behind the tall glass doors to he left of 
the 6 tape readers in the USS IOWA picture). These monitor tapes are 
kept for backup, but are rarely looked at.

Is the four-printer waterfall in the USS IOWA picture also monitoring 
outgoing messages?  Why would you need a page printer copy of an 
outgoing message?  You can only read about 60 lines on the page printer, 
then the paper goes inside the cabinet to a take-up reel.

Does anyone know how these waterfalls were used in the Navy Comm 
Centers? (or any other comm centers? I always thought the the Army only 
used Kleinschmidts in their comm centers, but Tom reports seeing 
Teletype Corp. M28s in the Army in Germany. The Army apparently used the 
the waterfalls also, as there is an Army TM 11-5815-264-xx that covers 
the M28, including the waterfalls.)


Another mystery is who this waterfall was built for.  I initially 
thought the Navy, since all the pictures of waterfall installations I 
had seen had been Navy. But Nick pointed out it is the wrong color for 
the Navy!  It was modified for TEMPEST, so it must have been built to be 
used in high security communications somewhere. But not in military, as 
there is no military ID on the cabinet.  Has anyone ever seen a 
waterfall in a secure comm center that was not military (CIA, FBI, State 
Dept.)?

Thanks & have fun,

Duncan Brown, K2OEQ
USASA    31J30

Antique Wireless Assoc. Museum,
   Asst. Curator, Commercial Equipment
(also chief TTY op & repairman)

www.antiquewireless.org


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