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#1
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d'Arsonval Movement Repair
One thing I do for fun is refurbish Dorrough Discriminate Audio
Processors. It's been a thing for me for years. Over that time, however, I'm understandably seeing an increase in the number of VU meters that are sticky. The one of the bench now has two meters that need to be replaced or repaired. Replacements (Modutec) are not available, and repairs are tough. As an experiment, I connected my function generator to one of the sticky meters are started hitting it with 2 Hz. As the movement seems to free up, I increase the swing such that it eventually reaches full scale high and low. The first meter I did this too seems to be working normally. The second one is undergoing treatment at the moment. Based on a previous recommendation here a long time ago, I got some super fancy oil for the movements. At that time, I tried oiling a couple of movements. It didn't help either one. Either I got the oil in the wrong place, or oil wouldn't solve the problem. My question is, if this conditioning process frees up the movement, how likely is the movement likely to function before it starts freezing again? Alternatively, does anyone repair meters any more? |
#2
Posted to rec.audio.pro
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d'Arsonval Movement Repair
In article ,
mcp6453 wrote: One thing I do for fun is refurbish Dorrough Discriminate Audio Processors. It's been a thing for me for years. Over that time, however, I'm understandably seeing an increase in the number of VU meters that are sticky. The one of the bench now has two meters that need to be replaced or repaired. Replacements (Modutec) are not available, and repairs are tough. As an experiment, I connected my function generator to one of the sticky meters are started hitting it with 2 Hz. As the movement seems to free up, I increase the swing such that it eventually reaches full scale high and low. The first meter I did this too seems to be working normally. The second one is undergoing treatment at the moment. Based on a previous recommendation here a long time ago, I got some super fancy oil for the movements. At that time, I tried oiling a couple of movements. It didn't help either one. Either I got the oil in the wrong place, or oil wouldn't solve the problem. My question is, if this conditioning process frees up the movement, how likely is the movement likely to function before it starts freezing again? Alternatively, does anyone repair meters any more? MCP- Meters I have come across, had dry "jeweled" movements. Something like needle points riding in depressions or holes in jewels of some kind. Your sticky movements may be due to use of lubricants that dried. You might try using a solvent to unstick them. Fred |
#3
Posted to rec.audio.pro
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d'Arsonval Movement Repair
On 12/25/2019 12:44 PM, Fred McKenzie wrote:
In article , mcp6453 wrote: MCP- Meters I have come across, had dry "jeweled" movements. Something like needle points riding in depressions or holes in jewels of some kind. Your sticky movements may be due to use of lubricants that dried. You might try using a solvent to unstick them. What kind of solvent would you suggest, and how would I apply it? I don't exactly know how these movements are put together. Where is the pivot point? |
#4
Posted to rec.audio.pro
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d'Arsonval Movement Repair
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#5
Posted to rec.audio.pro
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d'Arsonval Movement Repair
On 25/12/2019 11:44 am, Fred McKenzie wrote:
In article , mcp6453 wrote: One thing I do for fun is refurbish Dorrough Discriminate Audio Processors. It's been a thing for me for years. Over that time, however, I'm understandably seeing an increase in the number of VU meters that are sticky. The one of the bench now has two meters that need to be replaced or repaired. Replacements (Modutec) are not available, and repairs are tough. As an experiment, I connected my function generator to one of the sticky meters are started hitting it with 2 Hz. As the movement seems to free up, I increase the swing such that it eventually reaches full scale high and low. The first meter I did this too seems to be working normally. The second one is undergoing treatment at the moment. Based on a previous recommendation here a long time ago, I got some super fancy oil for the movements. At that time, I tried oiling a couple of movements. It didn't help either one. Either I got the oil in the wrong place, or oil wouldn't solve the problem. My question is, if this conditioning process frees up the movement, how likely is the movement likely to function before it starts freezing again? Alternatively, does anyone repair meters any more? MCP- Meters I have come across, had dry "jeweled" movements. Something like needle points riding in depressions or holes in jewels of some kind. Your sticky movements may be due to use of lubricants that dried. You might try using a solvent to unstick them. Fred My dad repaired watches when I was a kid. A lot of them started working after he flushed them out with naphtha. Seems they get gummed up after a while. |
#6
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d'Arsonval Movement Repair
On Thursday, December 26, 2019 at 5:25:48 AM UTC-5, gray_wolf wrote:
My dad repaired watches when I was a kid. A lot of them started working after he flushed them out with naphtha. Seems they get gummed up after a while. Does that work on kidney stones too? Regards, Ty Ford |
#7
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d'Arsonval Movement Repair
On 26/12/2019 15:40, Ty Ford wrote:
Does that work on kidney stones too? Nah, they need ultrasound. 18 to 20 kHz full scale with the output power turned well up with some second and third harmonic distortion and a high pass filter. Just don't ask what speaker you need or where you have to put it. -- Tciao for Now! John. |
#8
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d'Arsonval Movement Repair
On 26/12/2019 9:40 am, Ty Ford wrote:
On Thursday, December 26, 2019 at 5:25:48 AM UTC-5, gray_wolf wrote: My dad repaired watches when I was a kid. A lot of them started working after he flushed them out with naphtha. Seems they get gummed up after a while. Does that work on kidney stones too? Regards, Ty Ford No. I don't think so. Ultrasonics may be the way to go. :-) |
#9
Posted to rec.audio.pro
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d'Arsonval Movement Repair
On 12/25/2019 11:33 AM, mcp6453 wrote:
does anyone repair meters any more? That's questionable. There was a guy larsonmetercraft.com who repaired meters - the name comes up on the Ampex List now and then. But when I checked the web site to see if he was still in business, I got a starter WordPress page. Maybe it's going to be a new web site, or maybe he retired. A web search turns up a Google map page with a phone number (619) 258-8990. Also, there's a web page: https://www.hybridelectronics.com/ma...c-distributors that has a link to Larson-Metercraft that gets back to that WordPress page. Hybrid Electronics appears to be a general electronic parts distributor on the other side of the country from the larsonmetercraft.com map. Very mysterious. -- For a good time, call http://mikeriversaudio.wordpress.com |
#10
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d'Arsonval Movement Repair
mcp6453 wrote:
On 12/25/2019 12:44 PM, Fred McKenzie wrote: In article , mcp6453 wrote: MCP- Meters I have come across, had dry "jeweled" movements. Something like needle points riding in depressions or holes in jewels of some kind. Your sticky movements may be due to use of lubricants that dried. You might try using a solvent to unstick them. What kind of solvent would you suggest, and how would I apply it? I don't exactly know how these movements are put together. Where is the pivot point? If you've got watch oil, put it on the point where that center axle that goes through the needle touches the frame that holds it in place at the ends (the pivot point). It will be enough of a solvent to dissolve whatever old lube might be on there. Just flatten the edge of a toothpick and use it as a brush to carry some oil over. It will not take much, maybe not even enough to see. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
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