Great Old He-Ne Laser Communications Demo System

[Eidetic]

This one's a real treat. It's a portable laser communications demonstration system made by General Telephone & Electronics Laboratories of Bayside, New York. It arrived in an old 24x28x12" travel case on wheels with a large classy logo on the side, and covered with packing tape that I quickly removed. While removing the tape, some of the old shipping labels came off and I found what appears to be the original one under one of them as seen below, giving a date to the contents of c1969.


First thing I found inside is a fold-out metal hologram display! Nothing said about that in the Ebay listing. I'll add pics of that after I clean the old packing tape off the front surface mirror, and reattach it. Below that was the laser, a speaker with a detector mounted on the side, an interface box, and a microphone.


Here's the system spread out. I love the perforated metal cover and the grille cloth on the speaker, both screaming the late '60s. The plasma tube has mirrors on both ends with only the rear being adjustable, and Brewster windows inside on both ends too. It works (there ya go Phil), but didn't lase. There's a removable negative lens on the output bezel, to spread the beam for hologram illumination. It has a great set of adjustable feet, a phono jack input on the back, and a label on the front that says it is a model L-15M made by Energy Technology Incorporated. The interface box was also made by ETI (model LM-1), so I think they made those components for GTE. There are GTE labels on the hologram display (model HDA2, Serial #4) and the speaker (model LCDSP, Serial #4).


The laser baseplate and the plasma tube look like early pieces made by CW Radiation (that eventually merged with Aerotech). The front bezel looks exactly like one I see in a picture of a laser made in 1964 by Energy Systems Incorporated of Palo Alto, CA. CW Radiation was also in Silicon Valley. I'm thinking Energy Systems Inc became Energy Technology Inc, and eventually CW Radiation (whose earliest reference I can find is the early '70s). This system will look GREAT when eventually displayed properly among the rest of the collection. I have a similar demo system made by Heathkit/Zenith in the mid-'80s.

[Eidetic]

Here's the hologram display that came with the kit. It's painted aluminum, and the vertical sections unfold on piano hinges. Apparently the diverging laser beam enters from the left, bounces off the mirror and illuminates the transmission hologram from behind. A two inch riser would place the laser's output at the same height as that needed for both the speaker and this display, so I think it's a missing piece. Notice the large holes in the base of the display on the left that I think registered the riser.

[142laser]

Bob if the tube will not come back and lase we will look for a similar one that works. How long?
Please send detailed tube pics.