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#1
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Thorens TD 126 MK II electonic
The speed control indicator no longer lights.
Is there anything easily replaceable? Does the mirror I found when I opened the base have anything to do with it? To use a disc on the spindle, do I need a fluorescent light or is any 60HZ electric light okay I can't find my General Radio Strobotach:-) TIA Abbedd |
#2
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Thorens TD 126 MK II electonic
"ansermetniac" wrote in message ... The speed control indicator no longer lights. Is there anything easily replaceable? Does the mirror I found when I opened the base have anything to do with it? To use a disc on the spindle, do I need a fluorescent light or is any 60HZ electric light okay I can't find my General Radio Strobotach:-) TIA Abbedd Usually a bad neon lamp. Modern neon's are mostly made-in China crap and don't last long. Any 60 hz lamp would work, but neon is better since the glow isn't quite as persistent as incandescent. Mark Z. |
#3
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Thorens TD 126 MK II electonic
"ansermetniac" wrote in message
The speed control indicator no longer lights. Is there anything easily replaceable? Usually, a neon tube. As others have pointed out, neon tubes have become crap, but it should be possible to work something out with a LED. Does the mirror I found when I opened the base have anything to do with it? It reflects markings on the underside of the turntable. To use a disc on the spindle, do I need a fluorescent light or is any 60HZ electric light okay Fluorescents work better, but a low-wattage incadescent should work, sort of/ I can't find my General Radio Strobotach:-) |
#4
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Thorens TD 126 MK II electonic
In article ,
ansermetniac wrote: Does the mirror I found when I opened the base have anything to do with it? If I recall correctly, the mirror (on turntables like this, not necessarily the TD 126 specifically) is there so that you can down into an opening in the table, and see the strobe-disk which is actually fastened to the underside of the platter. The mirror isn't part of the electrical system. According to the manual, the strobe bracket can be moved to different positions, letting you see different portions of the strobe disk - one for 50 Hz operation, and one for 60 Hz operation. To use a disc on the spindle, do I need a fluorescent light or is any 60HZ electric light okay An incandescent 60 Hz light won't work well, as these don't flicker appreciably - the filament remains hot and emits light even during the zero-voltage-crossover part of the 60 Hz waveform. A fluorescent will work. The service manual for the TD 126 MK II (available as a free download from http://www.vinylengine.com/library/thorens/td126.shtml) says that the strobe uses a neon bulb, in a socket of some sort. Neons are the lamp-of-choice for simple built-in strobe-disk applications like this, as they flicker nicely and are inexpensive and long-lived. I'd suggest that you download the manual, and read the procedure to access the neon bulb and remove it (unplug power first, there's line voltage on the socket contacts!) and then look for a suitable replacement. My current Mouser catalog lists three different sizes/styles of neon bulbs with bases of one sort or another - possibly one of these will fit the socket in the Thorens. If worse comes to worst you might be able to remove the socket for the neon bulb, and hardwire-in a new-style neon indicator somehow. -- Dave Platt AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
#5
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Thorens TD 126 MK II electonic
On Wed, 12 Nov 2008 20:08:54 -0500, ansermetniac
wrote: The speed control indicator no longer lights. Is there anything easily replaceable? Does the mirror I found when I opened the base have anything to do with it? To use a disc on the spindle, do I need a fluorescent light or is any 60HZ electric light okay Other folks have already covered the bases, but in case you can't find a factory lamp: In those days a strobe lamp was typically a GE NE-2 bulb with a series 100K or so resistor (at 115 volts). Sometimes as large as 220K. Modern resistors' voltage ratings become important here, so a two watt or larger resistor might be surprisingly important these days. The whole contraption ran at line voltage, so safety considerations, when "re-engineering" become very, very important. Do NOT procede unless you are capable of the safety level required. I **** thee not. All the best fortune, Chris Hornbeck |
#6
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Thorens TD 126 MK II electonic
"ansermetniac" wrote in message ... The speed control indicator no longer lights. Is there anything easily replaceable? Does the mirror I found when I opened the base have anything to do with it? To use a disc on the spindle, do I need a fluorescent light or is any 60HZ electric light okay I can't find my General Radio Strobotach:-) **I've done a few of these with LEDs. The original neon was a big (expensive) sucker. MUCH larger than NE-2 and other types. If you can find a friend with some electronic nouse, ask them to wire up some nice, bright LEDs (blue ones look way cool) in place of the neon. The result will be a long lasting, bright and clear speed indicator. Naturally, you need to drive the LED with mains frequency. This is not difficult stuff. -- Trevor Wilson www.rageaudio.com.au |
#7
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Thorens TD 126 MK II electonic
On Thu, 13 Nov 2008 17:27:58 +1100, "Trevor Wilson"
wrote: **I've done a few of these with LEDs. The original neon was a big (expensive) sucker. MUCH larger than NE-2 and other types. If you can find a friend with some electronic nouse, ask them to wire up some nice, bright LEDs (blue ones look way cool) in place of the neon. The result will be a long lasting, bright and clear speed indicator. Naturally, you need to drive the LED with mains frequency. This is not difficult stuff. Several caveats: NE-2's should be free from anybody over a certain age, if you know what I mean. Geezers have boxes of 'em. No magic was involved in their manufacture and they last for many decades. Neons fired bidirectionally (120Hz for 60Hz Edison). LED's don't. Neons arc'd over at about 60 to 80 volts. LED's are semiconductors and operate a little differently... But an easily visible green LED would be a substantial improvement for strobe use, if all else were taken into account. All the best fortune, Chris Hornbeck |
#8
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Thorens TD 126 MK II electonic
"Trevor Wilson" wrote
in message **I've done a few of these with LEDs. The original neon was a big (expensive) sucker. MUCH larger than NE-2 and other types. If you can find a friend with some electronic nouse, ask them to wire up some nice, bright LEDs (blue ones look way cool) in place of the neon. The result will be a long lasting, bright and clear speed indicator. Naturally, you need to drive the LED with mains frequency. This is not difficult stuff. LEDs should give a really clear strobe pattern because they turn on and off very much faster than incadescent, flourescent, or gas-discharge bulbs. LEDs are the active ingredients in TOSlink transmitters, which flash on and off cleanly up to 50 MHz. The only trick is driving them, as they are a capacitive load at high frequencies. Seems like a regular LED, and maybe a 2 watt 27 K resistor in series would work for 110 volts, and a 5 watt 47K resistor for 220. Here's a web site with data and resistor calculators: http://www.theledlight.com/technical.html |
#9
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Thorens TD 126 MK II electonic
Chris Hornbeck wrote:
On Thu, 13 Nov 2008 17:27:58 +1100, "Trevor Wilson" wrote: **I've done a few of these with LEDs. The original neon was a big (expensive) sucker. MUCH larger than NE-2 and other types. If you can find a friend with some electronic nouse, ask them to wire up some nice, bright LEDs (blue ones look way cool) in place of the neon. The result will be a long lasting, bright and clear speed indicator. Naturally, you need to drive the LED with mains frequency. This is not difficult stuff. Several caveats: NE-2's should be free from anybody over a certain age, if you know what I mean. Geezers have boxes of 'em. No magic was involved in their manufacture and they last for many decades. Neons fired bidirectionally (120Hz for 60Hz Edison). LED's don't. Neons arc'd over at about 60 to 80 volts. LED's are semiconductors and operate a little differently... But an easily visible green LED would be a substantial improvement for strobe use, if all else were taken into account. All the best fortune, Chris Hornbeck Off the top of my head, wouldn't a pair of LEDs, each firing from the opposite phase of the AC, visually sum to a 120Hz 'flicker'? jak |
#10
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Thorens TD 126 MK II electonic
In article , jakdedert wrote:
Chris Hornbeck wrote: On Thu, 13 Nov 2008 17:27:58 +1100, "Trevor Wilson" wrote: **I've done a few of these with LEDs. The original neon was a big (expensive) sucker. MUCH larger than NE-2 and other types. If you can find a friend with some electronic nouse, ask them to wire up some nice, bright LEDs (blue ones look way cool) in place of the neon. The result will be a long lasting, bright and clear speed indicator. Naturally, you need to drive the LED with mains frequency. This is not difficult stuff. Several caveats: NE-2's should be free from anybody over a certain age, if you know what I mean. Geezers have boxes of 'em. No magic was involved in their manufacture and they last for many decades. Neons fired bidirectionally (120Hz for 60Hz Edison). LED's don't. Neons arc'd over at about 60 to 80 volts. LED's are semiconductors and operate a little differently... But an easily visible green LED would be a substantial improvement for strobe use, if all else were taken into account. All the best fortune, Chris Hornbeck Off the top of my head, wouldn't a pair of LEDs, each firing from the opposite phase of the AC, visually sum to a 120Hz 'flicker'? Right..You can also use a bridge to drive one. I think the orinal neon was fairly long, but that no problem. You can use a light guide or multiple LED's My preference is blue, but blue has a lot more fogging effect than red or orange. You can use large resistors to drive from HV lines. It's just is way less efficient. greg |
#11
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Thorens TD 126 MK II electonic
GregS wrote:
In article , jakdedert wrote: Chris Hornbeck wrote: On Thu, 13 Nov 2008 17:27:58 +1100, "Trevor Wilson" wrote: **I've done a few of these with LEDs. The original neon was a big (expensive) sucker. MUCH larger than NE-2 and other types. If you can find a friend with some electronic nouse, ask them to wire up some nice, bright LEDs (blue ones look way cool) in place of the neon. The result will be a long lasting, bright and clear speed indicator. Naturally, you need to drive the LED with mains frequency. This is not difficult stuff. Several caveats: NE-2's should be free from anybody over a certain age, if you know what I mean. Geezers have boxes of 'em. No magic was involved in their manufacture and they last for many decades. Neons fired bidirectionally (120Hz for 60Hz Edison). LED's don't. Neons arc'd over at about 60 to 80 volts. LED's are semiconductors and operate a little differently... But an easily visible green LED would be a substantial improvement for strobe use, if all else were taken into account. All the best fortune, Chris Hornbeck Off the top of my head, wouldn't a pair of LEDs, each firing from the opposite phase of the AC, visually sum to a 120Hz 'flicker'? Right..You can also use a bridge to drive one. I think the orinal neon was fairly long, but that no problem. You can use a light guide or multiple LED's My preference is blue, but blue has a lot more fogging effect than red or orange. You can use large resistors to drive from HV lines. It's just is way less efficient. greg How efficient do you need to be for this application? jak |
#12
Posted to rec.audio.tech
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Thorens TD 126 MK II electonic
"ansermetniac" wrote ...
The speed control indicator no longer lights. Is there anything easily replaceable? Does the mirror I found when I opened the base have anything to do with it? To use a disc on the spindle, do I need a fluorescent light or is any 60HZ electric light okay I can't find my General Radio Strobotach:-) A fluorescent with an old-time magnetic ballast will produce mains-frequency flicker. But the new compact fluorescents (CFL) use high-frequency (many KHz) electronic switching ballasts and are useless for stroboscopic use. LEDs with appropriate circuitry driven directly from the mains power are likely the practical answer today. |
#13
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Thorens TD 126 MK II electonic
"Chris Hornbeck" wrote in message ... On Thu, 13 Nov 2008 17:27:58 +1100, "Trevor Wilson" wrote: **I've done a few of these with LEDs. The original neon was a big (expensive) sucker. MUCH larger than NE-2 and other types. If you can find a friend with some electronic nouse, ask them to wire up some nice, bright LEDs (blue ones look way cool) in place of the neon. The result will be a long lasting, bright and clear speed indicator. Naturally, you need to drive the LED with mains frequency. This is not difficult stuff. Several caveats: NE-2's should be free from anybody over a certain age, if you know what I mean. Geezers have boxes of 'em. No magic was involved in their manufacture and they last for many decades. **And NE-2s are not suitable for the TD126. They're way too small and dim. Neons fired bidirectionally (120Hz for 60Hz Edison). LED's don't. **Yep. Again, it is easy enough to organise an LED to work properly in this situation. Neons arc'd over at about 60 to 80 volts. LED's are semiconductors and operate a little differently... **The Td126 is thoughtfully fitted with a low Voltage AC supply system. But an easily visible green LED would be a substantial improvement for strobe use, if all else were taken into account. **Indeed. Blue looks way cooler though. I've used red, green and blue LEDs. The blue ones are much preferred by most people. -- Trevor Wilson www.rageaudio.com.au |
#14
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Thorens TD 126 MK II electonic
"Chris Hornbeck" wrote in
message On Thu, 13 Nov 2008 17:27:58 +1100, "Trevor Wilson" wrote: **I've done a few of these with LEDs. The original neon was a big (expensive) sucker. MUCH larger than NE-2 and other types. If you can find a friend with some electronic nouse, ask them to wire up some nice, bright LEDs (blue ones look way cool) in place of the neon. The result will be a long lasting, bright and clear speed indicator. Naturally, you need to drive the LED with mains frequency. This is not difficult stuff. Several caveats: NE-2's should be free from anybody over a certain age, if you know what I mean. Geezers have boxes of 'em. No magic was involved in their manufacture and they last for many decades. Neons fired bidirectionally (120Hz for 60Hz Edison). LED's don't. Neons arc'd over at about 60 to 80 volts. LED's are semiconductors and operate a little differently... Yes, but strobes stop repeated images like a strobe disk, when you flash them at submultiples of the design frequency, so it doesn't matter. |
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