Du Mont Cathode -ray Oscillograph type 208

[djrm]

I returned home from a local radio rally sale with this Du Mont Cathode -ray Oscillograph type 208 today.
Jenny didn't seem too impressed so I thought I'd how it here! I'm going to try and make it work.
It is quite old, a '40s design. looks clean inside and untouched. Schematics and manual are online. 
The picture shows it together with an unusual 50 / 60 Hz vibrating reed frequency meter.
I also found a Videcon  camera which looks nicely made in a big blue box with drop down side panels.
A fruitful day out, I just need to find a bit of room to store them now.
   

[ppppenguin]

Since DuMont is a US manufacturer and not much of their kit reached the UK please make sure of the mains voltage setting.

"Oscillograph" is odd terminology as it suggests an instrument that can make a record of the results. For example "spectrograph" is a recording instrument (often on film) while a "spectroscope" is a direct viewing device. Just like an oscilloscope. AFAIK the 'scope vs 'graph terminology was established before WW2.

Would like to see a pictre of the camera please.

[Mike Watterson]

Still, my first scope was a Cossor oscillograph. 51 hits on the Radiomuseum. The ones I looked at are scopes. Some as late as 1970. Most are RCA and DuMont, but some other brands and countries.
I do agree it doesn't make sense. Nor does the US calling gramophones, phonographs. On two levels! The original French phonograph did just record a pattern, not play it. Edison made a small change to the cylinder system so it could play. The gramophone was always a disc, so could easily be pressed. Though curiously there was the Graphophone Company. Though I may have spelled it wrong.

Is Television correct? Or Quadrasonic?

[signalman4]

I've got one of these Du Mont type 208 scopes if you would like another one for spares. IIRC its in fairly good condition but hasnt been powered for a long time - like 15 years or more. From memory it has some 6V6 valves in there and these and some others are mounted upside down.

[djrm]

Greetings everyone,

I bought the old 'scope in from the shed and it has been next to a radiator for a couple of weeks to dry out nicely. Yesterday I turned it on to see what it did, well one capacitor was getting warm and leaking wax, and another was dead short after a while. 

Thankfully, the tube is ok and most functions seem to work although the pots are a bit noisy. Here is old and new working together with the 'scope showing a clock display generated with an ESP32 as an NTP time receiver.
   
There is a problem withthe frequency response which is causing the distortion in the number display, I'll investigate the and see if it can be improved. A more modern 'scope without very high frequency response shows a much better clock display.

Arduino 'ESP32 OscilloscopeClock' here: https://github.com/maurohh/ESP32_OscilloscopeClock

[Kalee20]

Agree on use of terminology, but then 'graph' is just a process of drawing. Like 'photograph' drawing with the aid of light. On that basis, it's arguable that an instrument which draws oscillations on the screen of a tube could be called an 'oscillograph' rather than the permanent record of those oscillations (or would that have been called an 'oscillogram?'

Electric trains pick up power via a 'pantograph' although no record is being made, it's so-called because it looks like the drawing/scaling instrument called a 'pantograph'. Though even then, it's the name given to the instrument, not the drawn record!

Sorry, no help to the OP! But curious about the terminology!

[ppppenguin]

There's something Dali-esque about that clock

[Terry]

On the subject of terminology, I've only just spotted this:

Nor does the US calling gramophones, phonographs.

I'm sure I read somewhere that the name 'gramophone' was copyrighted in the US by the first manufacturer to put these devices on the market, so competitors had to fall back on the use of phonograph and successfully managed to convince the public that their 'phonographs' performed the identical function to the competition.

Unfortunately, the gramophone manufacturer omitted to copyright the name in the UK ...!

[ppppenguin]

Gramonphone was a Berliner trademark.: https://en.wiktionary.org/wiki/gramophone

Phonograph:
https://www.etymonline.com/word/phonograph
Including: "The recording made from it at first was called a phonogram (1879)."
https://en.wiktionary.org/wiki/phonograph

Don't forget the Columbia Graphophone Company. Note the spelling. Merged with the Gramophone Company (HMV) to form EMI in 1931.

[ppppenguin]

PS: I forgot that the means of recording sound in a visible form, literally a phonograph, predates the ability to replay such sounds. It was Edison who hit on the idea of being able to replay such sounds, when he was working on a means of recording morse code.