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Post by Moooperator on Feb 9, 2009 18:26:30 GMT -6
Steve, I think that's the hat I used to wear in the corner at school?
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schweg
Three Spring Motor
Posts: 218
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Post by schweg on Feb 9, 2009 18:31:13 GMT -6
I was trying to get my wife to try it on for the picture but nearly got it dented in the process...
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Post by phonogfp on Feb 9, 2009 18:32:57 GMT -6
If they are 180deg out of phase then this cannot be a simple "T". This must share a common diaphragm and port sound out each side of it. Is that correct? Were these used to increase volume (in one direction, like a Polyphone) or was it used to project sound in different directions? I thought I remembered seeing a drawing with horns pointing in opposite directions. Yes, the Edison Duplex ported sound from each side of the diaphragm, and was indeed intended to project sound in different directions, which would also lessen the out-of-phase effect to a listener. At $15.00, very few felt compelled to buy one! I must be a stickler and point out that the Polyphone didn't increase volume, despite advertising claims of the time. It merely doubled the signal, which doesn't increase volume any more than adding a speaker to one's receiver does. The Polyphone did, however, create that "echo" effect which was sort of an artificial acoustic reverb - something I've never seen claimed for it (you read it here first!). I should have included that in Gadgets! If you have two identical 26" conical horns and floor stands, you can create a similar visual (not acoustic) effect to the Edison Duplex by using a "T" joint available in most any hardware store. I nickel-plated a copper one, and attached one end of the "through pipe" to the reproducer. This leaves two open ends at approximately 45-degree angles above the machine. Attach the rubber tubes on the horns, and fool your collector friends - for a few moments anyway! George P.
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Post by MTPhono on Feb 10, 2009 11:03:02 GMT -6
I should have stated "attempted volume increase of the Polyphone".
By your terminology though, a "doubling of the signal" is the exact same as a 3db gain/increase in volume! In fact the problem and confusion with this terminology is that the signal IS NOT doubled if the music is varying faster than about 200ms (which it is on a Polyphone). If for example a non-varying signal was recorded on a cylinder (ex. a single note played on a trumpet) and played back on the Polyphone the signal would be exactly doubled.
The reason the Polyphone output can't be considered an amplified signal is that the two reproducers are offset by 200-300ms thus the signal at any point in time is NOT the same signal (out of both reproducers). The reproducers would have to contact the record at the exact same spot at the same time. Obviously this isn't physically possible.
The Duplex is the exact same signal but one is 180deg out of phase so that too may not be considered amplification.
The only two mechanically-amplified systems were based on the Auxeto-Gramophone and Higham principles prior to electrically amplified systems.
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Post by phonogfp on Feb 10, 2009 11:39:32 GMT -6
I should have stated "attempted volume increase of the Polyphone". By your terminology though, a "doubling of the signal" is the exact same as a 3db gain/increase in volume! In fact the problem and confusion with this terminology is that the signal IS NOT doubled if the music is varying faster than about 200ms (which it is on a Polyphone). If for example a non-varying signal was recorded on a cylinder (ex. a single note played on a trumpet) and played back on the Polyphone the signal would be exactly doubled. I stand corrected on my mis-use of the phrase, "doubling the signal." I should have written "duplicated the signal." George P.
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Post by catfishjohn on Feb 22, 2009 8:10:09 GMT -6
I came across this horn and was curious if anyone knows what it may have been used for? Is it a home made megaphone? It's tall - about 3 ft. Thanks - John
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Post by phonogfp on Feb 22, 2009 9:27:20 GMT -6
You don't show the other side - - is/was there a hanger? If so, that's indeed a phono horn. It certainly looks like someone soldered a piece of light fixture onto a phono horn to make a megaphone.
George P.
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Post by catfishjohn on Feb 22, 2009 11:33:33 GMT -6
Darn - I was hoping it was a rare recording contraption. It does have the hanger and I'm sure was originaly used for a phongraph. - John
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Post by rodpickett on Mar 7, 2009 15:21:55 GMT -6
For your interest. This is my first post to this message board and hope it works. Attached is a photo of a rare Edison West Point horn, mounted on an Edison Fireside. It was the last external horn offered by Edison and as you can see, it is a cross between an external norn and an internal Amberola horn. There is also a reference and drawing of this horn, mentioned in the Frow cylinder book. NOTE: Can't get a single photo to upload. Use following link to my online photo album to see four photos of the Edison West Point: picasaweb.google.com/rodpickett01/Phonographs#
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schweg
Three Spring Motor
Posts: 218
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Post by schweg on Mar 7, 2009 17:07:20 GMT -6
Rod- That's a neat pic of a rare horn. I remember seeing one sell on Ebay, I think it went pretty high. Amazing what the Edison Phonograph Works would do to utilize all those spare parts lying around..
Steve
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Post by Moooperator on Mar 7, 2009 21:05:37 GMT -6
Rod, I have learned something today. If I had seen that i would have thought the owner had jerry rigged some old Am 30 horn.... That an unusual set up. Would this have come out in the late teens or early 20's?
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Post by andersun on Mar 7, 2009 23:20:35 GMT -6
About a year and a half ago a nice West Point went on Ebay. I lost the bid at $4,200.00!
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Post by rodpickett on Mar 8, 2009 4:20:14 GMT -6
Reference West Point Horn
Your guess is as good as mine on the date. Late teens or early 20's seems to be about right. Most assume it is a cobbled Amberola horn; however, notice the Edison signature decal on the horn-bell. This would not have been on an unseen internal horn.
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Post by phonogfp on Mar 8, 2009 8:21:13 GMT -6
I don't recall seeing any Edison literature on the West Point horn, but my intuition leads me to put a date of about 1915 on these. This was the last year that Edison was selling external-horn machines (Firesides) as far as I know.
Note the Edison signature decal: the "Trade Mark" is all on one line, unlike the conventional version.
George P.
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Post by rodpickett on Mar 8, 2009 10:49:24 GMT -6
Another piece of trivia for your interest. In one of the West Point photos you’ll notice a small-framed photograph on top of my Edison B-80 Diamond Disc. I have also uploaded that photo. This photograph was taken in 1918 in the farmyard of my great-grandparents farm in Daviess County, Indiana. Pictured are my grandmother’s younger sister Jewell and infant brother Edwin – proudly showing their Edison Fireside phonograph, sitting on top of their sewing machine. Since they were dirt-poor farmers, we have no idea as to how they could afford a talking-machine. We speculate that they may have traded cattle or produce for it. Very common at the time, Jewell’s dress and Edwin’s cloths are made of used feed-sacks, as feed-sacks were made for that dual-purpose. My grandmother, Jewell and Edwin are all deceased. The Edison Fireside survives proudly in my collection but the horn has long since disappeared. I have no idea what happened to the sewing machine. picasaweb.google.com/rodpickett01/Phonographs#
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