Unusual WWII Edison Voice Writer for Telegraphers Training

[CDBPDX]

Here is something I picked up today, an Edison Voice Writer Code Transmitter and Recorder. The top appears to be a typical voice writer, it plays and records, and the bottom is a transmitter (I think). It is a model TG-8-C. I believe it was from 1941 and was used as a training aid for telegraphers. It still has a cylinder on it, 'Lesson 103', but it is very securely stuck there.

Does anybody know how this works? Thanks! Cliff

[Chuck]

It looks to me like it probably contains
an audio frequency oscillator, and an amplifier.

Probably the person using it would wear headphones
to listen to the morse code recorded on the practice
cylinder.

To record morse code onto a blank cylinder, a morse code
key would be plugged in and the machine set to "record"
mode.

Each time the key is pressed, the internal vacuum tube
audio oscillator would make a smooth audio tone recorded
on the cylinder. There's an option there to use
the "internal" tone source or to use some external
signal to be recorded.

This way, the person learning the code could practice
both sending and receiving.

[CDBPDX]

It looks to me like it probably contains
an audio frequency oscillator, and an amplifier.

Probably the person using it would wear headphones
to listen to the morse code recorded on the practice
cylinder.

To record morse code onto a blank cylinder, a morse code
key would be plugged in and the machine set to "record"
mode.

Each time the key is pressed, the internal vacuum tube
audio oscillator would make a smooth audio tone recorded
on the cylinder. There's an option there to use
the "internal" tone source or to use some external
signal to be recorded.

This way, the person learning the code could practice
both sending and receiving.

Excellent! Thank you very much!

So this is a regular Edison Voice Writer machine that is wired to only accept recording input from the oscillator tube instead of a voice microphone, and output to headphones or an external speaker..??

The Order No. is 3348-NY-41. Can this be interpreted as order 3348 in New York in 1941?

Cliff

[Chuck]

Not quite sure if it can *only* record morse
code. It's possible that by using the "external"
source option, that any sort of a signal could be
fed in and recorded, not just morse code.

That would depend partially on how the morse key is
in the circuit when it is plugged in.

For instance, possibly whatever external source is
used still gets turned on and off via the key.
So, if someone was attempting to record music fed
in to the "external" source terminals, the morse key
terminals may need to be shorted together in order to
get a constant signal through.

This would all be stuff that could be learned if the
machine can be fired up and tested.

Being old, and having sat around unused for many years,
there are probably electronic maintenance issues.
Very similar to vacuum tube type radios.

Some of the tubes might be weak or completely failed.
The electrolytic capacitors are most likely dried out
and have drifted way off from their original proper
capacitance values.

Hard to say without testing.

The old radio guys use a variac which is a variable
transformer to bring old equipment up to full operating
voltage slowly when firing up something which has
been sitting unused for years.

That way, right at first, the circuit might only
start out at say 50 volts AC, then if there's no
smoke or funny smells after a minute or so, the
variac is slowly turned up.

That machine you have there looks like it can
be restored without too much trouble.

[CDBPDX]

I think I fried it already. Plugged it in and turned it on and there was a bright white light from the tube on the far right for just a brief moment. After that, it still has a dim red glow but none of the other tubes light up. The mandrel spins easily by hand but the motor won't turn it. I think the motor wants to work but the mandrel doesn't spin. Needs work, for sure.

More detailed pictures here:

http://phonographs.cdbpdx.com/ECT-W/

[rgordon939]

If I'm not mistaken I saw this a few days ago while searching online for Edison Phonographs. What shocked me was the asking price of $24,000.00. Is this the same machine? Hope you got a better price.

Rich Gordon

[CDBPDX]

If I'm not mistaken I saw this a few days ago while searching online for Edison Phonographs. What shocked me was the asking price of $24,000.00. Is this the same machine? Hope you got a better price.

Rich Gordon

After some dickering, I ended up at $22,500. A steal!

Not really, I was high bidder at $110. A lot of money for something I know nothing about, but it was just too cool to pass up. This one came from Forest Grove, OR. Maybe I should fix this up and offer at only $15,000...??

Could you post a link to the $24,000 piece? I want to show it to my wife, who was not too thrilled that I came home with this.

[victorIIvictor]

"I think I fried it already."

To "amplify" (if you will) Chuck's warnings about electrolytic capacitor failure, Cliff, you may find this article helpful:

http://antiqueradio.org/recap.htm

Better to replace the capacitors for pennies then to spend $$$ on vacuum tubes or transformers (assuming you can even get them for such a machine).

Better late than never? Best wishes, Mark

[Phototone]

Some tubes flash upon turn on, but as long as you see a dull red glow from the filament after the flash, the tube should be ok.

[edisonphonoworks]

this seems to be of high quality military grade, is the recorder, reproducer, crystal or magnetic, if magnetic, it would be certainly worth restoring. Yes replace all capacitors, I have not seen many of the Electronic Ediphones actually functional. The ones that use Potassium sodium tartrate tetrahydrate usually fail and need rebuilding. Fix the capacitors, and have fun. It seems that rare cylinder, the plaster probably expanded and it is stuck, that is sad news try putting it in a warm room and put an ice pack on the mandrel end to cool the mandrel so the cylinder expands and the mandrel contracts. once you get the cylinder off ream it carefully so the ejectomatic still works.