EEVblog Electronics Community Forum
General => General Technical Chat => Topic started by: Simon on January 14, 2011, 08:09:26 pm
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I've got a "spirit of st. louise" "Field phone MK1" and the ringer bell in it does not work, are these fiaxable ? or is there any chance of getting another similar part ? there is plenty of room in the box for a different design bell
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picture?
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Yeah, a photo would help.
Also, how do you know that it doesn't work?
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the ringer circuit in most phones are relativity simple, a 470nF capacitor and a 1kohm or higher ringer load directly on the phone line will work
depending on what went wrong you'll need to measure the bell coil(s), it should be about 1k total and 500ohms per coil, if that measures fine test the 470nF cap, if its open or measures low capacitance you can replace that also make sure the hammer moves freely and strikes both bells
if one of the coils are open, depending on where it went open you can repair that just peel back the cover and find the winding wire where it broke and extend it or unwind it a few times and put it back on the solder point
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Yeah, a photo would help.
Also, how do you know that it doesn't work?
Well it worked last I used but now that I've put it back on it won't ring, I opened it up and put the meter over it and is was open circuit, then I rang the phone from my mobile and measured the AC voltage while it "rang" there was voltage but no ringing. So that's two nails in it's coffin, must be the bell. it's a small single bell.
I'll put a pic up later, if anyone remembers my former avatar that was it
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There is an possibility that if you rework the connection between the coil ends , and the contacts of the bell, to be able to work again.
But what matters is the picture of the bell it self .
General pictures of the device can be found on Google.
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well for now I will take the easy solution and get an external ringer thing,
the part I need to replace/repair consists of a bell with the coil with the hammer rod in it inside the bell so it is a very compact unit. as you say it is probably the wire come off the end but not having another phone I've ordered the external ringer and that will be that until i fix it if i bother now
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You might be able to pick up a replacement phone (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=120671270034) for the price of a bell!
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true, really I'd like to have it working, the external bell was £5.5 so a cheap fast solution. I've taken the bell off and will have a look at it, really I'd like to restore this unit as they don't make these phones anymore, yea mine may well go for something one day, when I boght it for £1.5 off a car boot sale it was listed for 100ish$ on the net, maybe I should have sold it then :-\
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Can you post pics of the original ringer? I have a connection for phone parts and may be able to find something. Include a ruler or dimensions if possible :)
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ok pictures attached. the bell is 38mm in diameter
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Ok, I'll see what I can find.
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Thank you most kind of you to offer your help