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#1
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Old brass telephone patch bay: recycle or junk?
Hi,,
I've dug up an old 50 jack (25x2) normalled and balanced rear-solderable rackmount brass telephone patch bay that's built like a tank. I'd like to clean it up and use it. It's designed for bantam plugs, but seems to handle 1/4" just fine. For each vertical pair, the ground is common and the front jacks mount to a rougly L-shaped brass plate to which the jack blades and switch blades are mounted. Testing it with a stereo plug reveals that contacts to hot and cold as well as the switched contacts read clean (0 ohms). But the common brass ground isn't clean at all due to extensive oxidation of the brass jacks which are quite dark and dirty. The brass plate is quite clean and reads 0 ohms, but even digging into the inner part of the front brass jacks the best I get is about 6 ohms. Questions: How can I clean the brass plugs easily and efficientlyl? I tried some Cramolin I had lying around, and it really didn't do much; I imagine it can't handle this degree of oxidation. The inner jacks are basically dark brown. Ideally, because I don't feel like taking the endire thing to pieces, I'd like to take each pair apart and just dip the frount ground part of the contacts into some corrosive cleaning solution. This front part extends 1/2" in front of the blades, so it's possible to physically do this. Is there a chemical that could do this? I also have 8 1/4" bantam patch cables but these are also brass and have the same degree of oxidation. What's the best way of cleaning these? Considering all of the above: am I wasting my time and should I just chuck this thing and move on? Thanks for any ideas. Steve |
#2
Posted to rec.audio.pro
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Old brass telephone patch bay: recycle or junk?
On Mar 13, 12:16 am, muzikwench wrote:
I've dug up an old 50 jack (25x2) normalled and balanced rear-solderable rackmount brass telephone patch bay that's built like a tank. I'd like to clean it up and use it. It's designed for bantam plugs, but seems to handle 1/4" just fine. You have your terminology mixed up. A bantam jack is about 3/16" in diameter and a 1/4" plug clearly won't fit. What you have are known as "long frame" jacks. Common audio style 1/4" plugs will fit, but people who are fussy about their long frame patchbays don't like to use them. Because the diameter of the tip is smaller on a long frame plug than on an audio plug (sorry, I don't know what else to call a "common" plug), a common plug will push the normalling contacts further apart than they were designed to move. This will eventually cause them to no longer make contact properly when there's no plug in the jack. I have been using several bays of jacks like what you have for about 30 years and use an occasional "visitor" plug but I'm careful not to leave it plugged in any longer than it needs to be. Mine still work fine, but like anything old, it needs a spritz of contact cleaner now and then. For each vertical pair, the ground is common and the front jacks mount to a rougly L-shaped brass plate to which the jack blades and switch blades are mounted. A common ground (sleeve) is usually not a problem but a lot of those telephone jack pairs are full-normalled and the normalling contacts are strapped together with pieces of metal - the parts of the two jacks are actually one piece. Does each jack have four terminals (tip, ring, tip switch, ring switch - not counting the common sleeve) or just two? If it has four, you can wire them half-normalled, which is what you usually want for a studio patchbay unless you're patching microphones. If it doesn't have terminals for the normalling switches, however, you'll need to determine how they're normalled (if at all) and decide if that's what you want. Some have no normalling contacts, so you can't normal them. How can I clean the brass plugs easily and efficientlyl? I tried some Cramolin I had lying around, and it really didn't do much; The PLUGS (what goes into the JACK) can be cleaned with Brasso or some other brass polish. They come out nice and shiny. You'll never get the jack parts to look shiny because you can't get to them unless you disassemble the jacks, and you DON'T want to do that - you wouldn't believe how many loose parts you'll have just with one jack pair!! But a shot of Cramolin, worked in with a plug, will restore electrical contact. This is good quality stuff. It takes a lot of time to wire a patchbay, but assuming the jacks aren't shot, it will serve you well. But it's really hard to tell how good the jacks are until they're in service for a while. The tip, ring, and sleeve contacts will survive a nuclear attack, but the switch contacts that normal a jack pair are what fail with time and crud. So you may find yourself with some crackles in a signal path that goes through a normalled pair of jacks. As long as contact cleaner works to fix that, you'll be OK, but eventually you'll have to replace the jack. |
#3
Posted to rec.audio.pro
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Old brass telephone patch bay: recycle or junk?
muzikwench writes:
Considering all of the above: am I wasting my time and should I just chuck this thing and move on? You are SO much better with a new improved cheapest chinese bidder unit than one that is engineered to last 40-50 years with hundeds of jacking cycles per day per jack. 600 grit GLASS paper, and a soft brass brush that is a light fit. Don't try to get it totally clean and shinny, just bring it back to a clean contact. |
#4
Posted to rec.audio.pro
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Old brass telephone patch bay: recycle or junk?
On Mar 13, 12:16 am, muzikwench wrote:
I've dug up an old 50 jack (25x2) normalled and balanced rear-solderable rackmount brass telephone patch bay that's built like a tank. I'd like to clean it up and use it. It's designed for bantam plugs, but seems to handle 1/4" just fine. This is a long frame 1/4" jack, not a bantam jack. It requires standard 1/4" long frame patch cords. If you use 1/4" short-frame "guitar amp" or "headphone" plugs, you'll wreck the springs. Markertek, though, has inexpensive long-frame patch cords. How can I clean the brass plugs easily and efficientlyl? I tried some Cramolin I had lying around, and it really didn't do much; The plugs just get cleaned with Brasso if they aren't plated. For the patchbay itself, the best thing to do is either to pull the whole thing apart and Brasso it (which should be done every few years, I think), or you should just use the cleaning plugs (available from Markertek) which polish the contact surfaces only. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#5
Posted to rec.audio.pro
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Old brass telephone patch bay: recycle or junk?
On Tue, 13 Mar 2007 00:16:32 -0400, muzikwench wrote
(in article ): Hi,, I've dug up an old 50 jack (25x2) normalled and balanced rear-solderable rackmount brass telephone patch bay that's built like a tank. I'd like to clean it up and use it. It's designed for bantam plugs, but seems to handle 1/4" just fine. For each vertical pair, the ground is common and the front jacks mount to a rougly L-shaped brass plate to which the jack blades and switch blades are mounted. Testing it with a stereo plug reveals that contacts to hot and cold as well as the switched contacts read clean (0 ohms). But the common brass ground isn't clean at all due to extensive oxidation of the brass jacks which are quite dark and dirty. The brass plate is quite clean and reads 0 ohms, but even digging into the inner part of the front brass jacks the best I get is about 6 ohms. Questions: How can I clean the brass plugs easily and efficientlyl? I tried some Cramolin I had lying around, and it really didn't do much; I imagine it can't handle this degree of oxidation. The inner jacks are basically dark brown. I sent mine for an ultrasonic bath. That worked really nicely. RCI in Rockville MD did them for me, but you may have someone local. Regards, Ty Ford --Audio Equipment Reviews Audio Production Services Acting and Voiceover Demos http://www.tyford.com Guitar player?:http://www.youtube.com/watch?v=4RZJ9MptZmU |
#6
Posted to rec.audio.pro
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Old brass telephone patch bay: recycle or junk?
I second that - used to send them to a pal at the BBC who put them through
an ultrasonic cleaning bath and they came lovely... A bit of Jif on the paintwork and they look like new. In the UK they are A guage (standard 1/4 2 jack) and B guage (GPO jack with smaller tip). Guy Ty Ford wrote: I sent mine for an ultrasonic bath. That worked really nicely. RCI in Rockville MD did them for me, but you may have someone local. Regards, Ty Ford --Audio Equipment Reviews Audio Production Services Acting and Voiceover Demos http://www.tyford.com Guitar player?:http://www.youtube.com/watch?v=4RZJ9MptZmU |
#7
Posted to rec.audio.pro
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Old brass telephone patch bay: recycle or junk?
On 13 Mar 2007 04:31:09 -0700, "Mike Rivers"
wrote: Mike and Scott: yes they are long frame. Wasn't sure of the terminology. Mike, sound advice on the plug types. FIY on the wiring: only hot, cold and ground terminals on each jack. The patchbay is full normalled. Un-normalling requires removal of thin metal jumper plates. This patchbay will be fine for my purposes. Thanks fo all for the cleaning tips. Since I posted this I found a discussion on the subject on Prodigy Pro: http://www.prodigy-pro.com/forum/vie...=asc&sta rt=0 I think ultrasonics is the safest bet. I'll see what I can find around here or order a "chepo" ultrasonic cleaner. You are SO much better with a new improved cheapest chinese bidder unit than one that is engineered to last 40-50 years with hundeds of jacking cycles per day per jack. Sarcasm aside, my feelings as well Thanks to all for the information and suggestions! |
#8
Posted to rec.audio.pro
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Old brass telephone patch bay: recycle or junk?
"Mike Rivers" wrote:
On Mar 13, 12:16 am, muzikwench wrote: I've dug up an old 50 jack (25x2) normalled and balanced rear-solderable rackmount brass telephone patch bay that's built like a tank. I'd like to clean it up and use it. It's designed for bantam plugs, but seems to handle 1/4" just fine. You have your terminology mixed up. A bantam jack is about 3/16" in diameter and a 1/4" plug clearly won't fit. What you have are known as "long frame" jacks. TO ALL HERE ~ I have a *pile* of de-commissioned long frame jack rows, some "open" from Switchcraft, some "boxed" from ADC. If anyone here wants any, they're yours for the shipping. Email me for an inventory and let me know what you can use. -- ~ Roy "If you notice the sound, it's wrong!" |
#9
Posted to rec.audio.pro
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Old brass telephone patch bay: recycle or junk?
On Tue, 13 Mar 2007 15:26:59 -0000, "Bigguy"
wrote: I second that - used to send them to a pal at the BBC who put them through an ultrasonic cleaning bath and they came lovely... A bit of Jif on the paintwork and they look like new. In the UK they are A guage (standard 1/4 2 jack) and B guage (GPO jack with smaller tip). Guy Ty Ford wrote: I sent mine for an ultrasonic bath. That worked really nicely. RCI in Rockville MD did them for me, but you may have someone local. A question about ultrasonic cleaning: I took apart one of the jack pairs to see how it was made and it looks like the insulating plates as well as the thin tubes used to insulate the ground screws (which hold the blades assembly together) are all phenolic. Can the phenolic survive the ultrasonic bath? Or must the assmbly be completely taken apart and only the metal components cleaned? TIA |
#10
Posted to rec.audio.pro
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Old brass telephone patch bay: recycle or junk?
muzikwench wrote:
I think ultrasonics is the safest bet. I'll see what I can find around here or order a "chepo" ultrasonic cleaner. A cheapo ultrasonic cleaner that can take a whole rack unit is going to be in the $500 range. On the OTHER hand, you can use it for record cleaning as well, and if you deal a lot with acetates or 78s it is worth every penny. If you are only using it occasionally it may be cheaper to find a local machine shop that will let you use theirs for a few bucks. Ask someone who does carb rebuilds. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#11
Posted to rec.audio.pro
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Old brass telephone patch bay: recycle or junk?
muzikwench wrote:
A question about ultrasonic cleaning: I took apart one of the jack pairs to see how it was made and it looks like the insulating plates as well as the thin tubes used to insulate the ground screws (which hold the blades assembly together) are all phenolic. Can the phenolic survive the ultrasonic bath? Or must the assmbly be completely taken apart and only the metal components cleaned? It will be fine. Most mild acids won't hurt phenolic. On the other hand, Formula 409 will etch the hell of the surface. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#12
Posted to rec.audio.pro
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Old brass telephone patch bay: recycle or junk?
On Tue, 13 Mar 2007 13:22:30 -0400, muzikwench wrote
(in article ): On Tue, 13 Mar 2007 15:26:59 -0000, "Bigguy" wrote: I second that - used to send them to a pal at the BBC who put them through an ultrasonic cleaning bath and they came lovely... A bit of Jif on the paintwork and they look like new. In the UK they are A guage (standard 1/4 2 jack) and B guage (GPO jack with smaller tip). Guy Ty Ford wrote: I sent mine for an ultrasonic bath. That worked really nicely. RCI in Rockville MD did them for me, but you may have someone local. A question about ultrasonic cleaning: I took apart one of the jack pairs to see how it was made and it looks like the insulating plates as well as the thin tubes used to insulate the ground screws (which hold the blades assembly together) are all phenolic. Can the phenolic survive the ultrasonic bath? Or must the assmbly be completely taken apart and only the metal components cleaned? TIA Not taken apart, but with little plugs to open the contacts. Regards, Ty --Audio Equipment Reviews Audio Production Services Acting and Voiceover Demos http://www.tyford.com Guitar player?:http://www.youtube.com/watch?v=4RZJ9MptZmU |
#13
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Old brass telephone patch bay: recycle or junk?
Not taken apart, but with little plugs to open the contacts.
Regards, Ty Thanks, I was thinking of doing that. Makes sense. One more question: is there such a thing as a conductive lacquer that would stop or at least significantly slow down any future oxidation of the brass? BTW: Brasso is amazing stuff |
#14
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Old brass telephone patch bay: recycle or junk?
muzikwench wrote:
Not taken apart, but with little plugs to open the contacts. Regards, Ty Thanks, I was thinking of doing that. Makes sense. One more question: is there such a thing as a conductive lacquer that would stop or at least significantly slow down any future oxidation of the brass? BTW: Brasso is amazing stuff If there were, we'd all be wealthy! Long ago, in anticipation of a strike, Management had the Maintenance Group check out all the audio gear and polish all the patch cord plugs. When one manager observed how bright and shiny they were, I said "Yes! And I've found a way to keep them that way ... Krylon Crystal Clear!" The Manager panicked and ran to my Supervisor to have someone test to see if I'd really done it! ;-) -- ~ Roy "If you notice the sound, it's wrong!" |
#15
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Old brass telephone patch bay: recycle or junk?
muzikwench wrote:
One more question: is there such a thing as a conductive lacquer that would stop or at least significantly slow down any future oxidation of the brass? Yup, nickel plating. It helps a lot. The oxidation isn't actually as much of a problem as it seems, because the plugs are designed to scrape it off of the tip and ring contacts when you plug and unplug them. They are self-cleaning. I think that the Gray Switchboard Company actually held a patent on the long-frame design around 1900 or so. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
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