Vintage Electronics - The Tefifon

[Homer J Simpson]

[VK3DRB]

I had never heard of a Tefifon before this.

I have a mate who owned an Elcaset player in 1977. He like it because of the superior audio frequency response and SNR to compared crappy cassette tapes. The tapes were very expensive and the technology died. CD's are pretty much dead now too.

[steve30]

I saw that video a while back. It was interesting because I came up with a similar idea quite a long time ago; doing something like a vinyl recording, but on a tape. I didn't realise anyone had actually done it .

[Homer J Simpson]

Here is another one that I never remember seeing or hearing about.

Worlds smallest cassette tape and it was a digital format !

[miguelvp]

That tefifon is brilliant.

I wonder if they borrowed the idea from talking dolls of the era.

[Ian.M]

Then there's the Dictaphone Dictabelt system:

Many, many years ago I dismantled a 50's model for parts.

And what about wire recorders?

[German_EE]

Homer J Simpson, please continue with these posts about old technology because I find them fascinating.

[tooki]

There's nothing on youtube about them, but if you love crazy old tech, google around for something called an Eidophor projector. Until the LCD came of age, it was the only video projection system capable of truly huge images. (Other light valve type projectors did exist, but AFAIK were more limited in terms of image size.) The only other projection technology at the time was CRT, which as you know produces rather dim images. Eidophor could project 60m pictures on the sides of buildings.

The Eidophor projected an image by bouncing light from a lamp onto a parabolic mirror, which rotated into a bath of special oil, onto which an electron gun would trace the image. (So yes, the rotating mirror, oil bath, etc. were all inside a vacuum tube.) The surface distortions in the oil deflected the light into the projection optics or onto a light dump (schlieren filter or something like that), creating the image. Apparently these things were huge (especially the 3-tube color ones), cost a fortune, and required great operator skill. No simple remote control or podium control panel if you wanted to turn one on — you'd call the AV specialist, who would begin the process, which apparently involved the compressors pumping a good vacuum, tuning it, and eventually an hour later it was ready to go!

I first heard of them in a very notable context: they were the projectors SRI used for Doug Engelbart's seminal presentation of the world's very first GUI, complete with mouse, often referred to as the "Mother of All Demos"!

(GE sold projectors using the same technology as "Talaria", IIRC.)

[free_electron]

why do they always use this horrible old-fart music in these demo's. can;t they show off how this equipment performs with something more modern like daft punk ?

[Radio Tech]

Yes thanks for posting this. I love vintage electronics and is 75% of what I work on today.

One of my next projects and future YT video will be the restore of this old Precision Apparatus Co series 10-15 Tube type tube tester. Along with ha ton of other old pieces.

Please by all means keep posting these. I really enjoy.