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6v & 90v DC Power supply
Do it the way the original radio did it -- dynamotor. You can still find
them in the back room at a lot of military surplus electronics junk stores. Jim |
6v & 90v DC Power supply
Hello Jim,
Do it the way the original radio did it -- dynamotor. You can still find them in the back room at a lot of military surplus electronics junk stores. But then be prepared for some major restoration. The bearings of a lot of these are nearly shot, mostly from sitting in an attic for decades. It's like old pond pumps. They run fine for a few weeks and then the racket increases, some weird noises appear, things get hot and they seize up. I restored an old Hammond organ. These generate the tones in a similar manner. A motor (plus a start motor) and over a hundred pickup coils on the long secondary shaft. 20 hours of hard work got it going again but we have accepted the fact that some of the bearings are pretty much over the hill. So it needs 2-3 starts to coax it to run without that mild screeching in the background. Getting spare parts from a company that went out of business 30 years ago just isn't going to happen. Regards, Joerg http://www.analogconsultants.com |
6v & 90v DC Power supply
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6v & 90v DC Power supply
On Tue, 27 Dec 2005 18:59:56 +0000, Joerg wrote:
Hello Jim, Do it the way the original radio did it -- dynamotor. You can still find them in the back room at a lot of military surplus electronics junk stores. But then be prepared for some major restoration. The bearings of a lot of these are nearly shot, mostly from sitting in an attic for decades. It's like old pond pumps. They run fine for a few weeks and then the racket increases, some weird noises appear, things get hot and they seize up. I restored an old Hammond organ. These generate the tones in a similar manner. A motor (plus a start motor) and over a hundred pickup coils on the long secondary shaft. 20 hours of hard work got it going again but we have accepted the fact that some of the bearings are pretty much over the hill. So it needs 2-3 starts to coax it to run without that mild screeching in the background. Getting spare parts from a company that went out of business 30 years ago just isn't going to happen. So, put the cam thingie on some sort of spindle, with some kind of depth gauge thingie, (maybe a slide pot and a stick), and map the disks, and just make the same waveform from ROM? Good Luck! Rich |
6v & 90v DC Power supply
Hello Rich,
I restored an old Hammond organ. These generate the tones in a similar manner. A motor (plus a start motor) and over a hundred pickup coils on the long secondary shaft. 20 hours of hard work got it going again but we have accepted the fact that some of the bearings are pretty much over the hill. So it needs 2-3 starts to coax it to run without that mild screeching in the background. Getting spare parts from a company that went out of business 30 years ago just isn't going to happen. So, put the cam thingie on some sort of spindle, with some kind of depth gauge thingie, (maybe a slide pot and a stick), and map the disks, and just make the same waveform from ROM? That has been tried many times. Several rather expensive electronic organs have come out claiming to emulate a Hammond. So far the real enthusiasts do anything to get their hands on the real thing, knowing that there will come a day when the last one croaks. IIRC it was Paul Shaffer (the guy who makes the music at david Letterman's show) who spent the equivalent of a luxury car to have one restored. Regards, Joerg http://www.analogconsultants.com |
6v & 90v DC Power supply
"David Harmon" wrote in message ... On Tue, 27 Dec 2005 05:58:18 GMT in sci.electronics.design, (John Crighton) wrote, This link tells you how to use the TL494 IC http://focus.ti.com/lit/an/slva001d/slva001d.pdf So why is the guy from TI showing NTE transistors for the power switching? Nothing in the TIP line good enough? Probably good enough for his measly 32 volts. I need to modify that circuit to work on outputs of 90 volts and 6 volts. |
6v & 90v DC Power supply
On Tue, 27 Dec 2005 21:27:31 +0000, Joerg wrote:
Hello Rich, I restored an old Hammond organ. These generate the tones in a similar manner. A motor (plus a start motor) and over a hundred pickup coils on the long secondary shaft. 20 hours of hard work got it going again but we have accepted the fact that some of the bearings are pretty much over the hill. So it needs 2-3 starts to coax it to run without that mild screeching in the background. Getting spare parts from a company that went out of business 30 years ago just isn't going to happen. So, put the cam thingie on some sort of spindle, with some kind of depth gauge thingie, (maybe a slide pot and a stick), and map the disks, and just make the same waveform from ROM? That has been tried many times. Several rather expensive electronic organs have come out claiming to emulate a Hammond. So far the real enthusiasts do anything to get their hands on the real thing, knowing that there will come a day when the last one croaks. IIRC it was Paul Shaffer (the guy who makes the music at david Letterman's show) who spent the equivalent of a luxury car to have one restored. Well, tastes vary, but really! Who wants a music box that makes it sound like you're at a skating rink? ;-P cheers! Rich |
6v & 90v DC Power supply
Hello Rich,
Well, tastes vary, but really! Who wants a music box that makes it sound like you're at a skating rink? ;-P Ok, I am not much of an expert on instruments or music in general. But a Hammond organ can fill a living room with a sound that, with the eyes closed, you'd think you are sitting in a cathedral. And lots of rock bands wouldn't use anything else. That is why a lot of Hammonds have been "sawed in halves" so they can be transported to the next gig. You could even buy split versions built into professional transport cases. Regards, Joerg http://www.analogconsultants.com |
6v & 90v DC Power supply
Joerg wrote:
Hello Rich, Well, tastes vary, but really! Who wants a music box that makes it sound like you're at a skating rink? ;-P Ok, I am not much of an expert on instruments or music in general. But a Hammond organ can fill a living room with a sound that, with the eyes closed, you'd think you are sitting in a cathedral. And lots of rock bands wouldn't use anything else. That is why a lot of Hammonds have been "sawed in halves" so they can be transported to the next gig. You could even buy split versions built into professional transport cases. Regards, Joerg http://www.analogconsultants.com They have a Hammond B3 at my church, with the Leslie speaker. There is another model Hammond in storage that needs a lot of work. Someone had it on their screened in porch and the finish is ruined, but it still plays. -- Service to my country? Been there, Done that, and I've got my DD214 to prove it. Member of DAV #85. Michael A. Terrell Central Florida |
6v & 90v DC Power supply
"Rich Grise, but drunk" wrote:
Well, tastes vary, but really! Who wants a music box that makes it sound like you're at a skating rink? ;-P cheers! Rich People like the old Hammond organs like the B3 because the can't go out of tune. The mechanical tone generator makes sure of that. They only sound like a skating rink in, get this, A SKATING RINK! -- Service to my country? Been there, Done that, and I've got my DD214 to prove it. Member of DAV #85. Michael A. Terrell Central Florida |
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