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Old 11th Jun 2022, 5:59 pm   #21
rambo1152
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Default Re: Magneto phone generates no ring voltage

Quote:
Originally Posted by joebog1 View Post
we didnt have a phone as kids, but my Nanna did ( aka grandmah ) on a party line.

j.b.
Joe, I'll be disappointed if you and your mates didn't have SCR-536 handie talkies like "The Terrible Ten"
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Old 12th Jun 2022, 4:57 am   #22
petervk2mlg
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Default Re: Magneto phone generates no ring voltage

I took the magneto assembly apart. Here are some pics. I'm unsure of the correct names for the various parts.
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Old 12th Jun 2022, 5:16 am   #23
FrankB
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Default Re: Magneto phone generates no ring voltage

One can put a NE2 bulb between the wires of f the generator and it should light if there is voltage. IIRC they strike between 60v and 90V. I have used old military field phone gennys to light the bulbs up.
The phone PS I have generate 90V for the ringer line.(likely less by the time it reaches the house).
I was rewiring the house phone lines and someone rang in. It was a pretty good jolt, as I was holding the lines at the time.
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Old 12th Jun 2022, 7:12 am   #24
joebog1
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Default Re: Magneto phone generates no ring voltage

Roger Ramjet,
NO !! it wasnt fence lines, but a single THICK copper wire. From memory ( and I am talking of my memory 60 years ago ) It was hard drawn copper about 1/8" thick
( 3mm in todays dollars, near enough ) Single insulator and not very high above the ground. Perhaps ten foot at the droop point.
The same phone line STILL exists!!!, and I have always wondered why some idiot hasnt pinched the copper wire!!. I would show pics except I moved to the next village 3000 kilometres by road north, so I cant take pics today.

Joe

Last edited by joebog1; 12th Jun 2022 at 7:13 am. Reason: spello
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Old 12th Jun 2022, 7:16 am   #25
joebog1
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Default Re: Magneto phone generates no ring voltage

Peter in Parkes,
That armature doent look in very exciting condition !!.
It may be black enamel ( which in itself is a disaster ), but it could be cooked.
It is VERY black!!.
UNless you have the patience of Jobe, rewinding is out of order.

Joe
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Old 12th Jun 2022, 8:13 am   #26
Roger Ramjet
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Default Re: Magneto phone generates no ring voltage

Yes the coil does look cooked but I wonder how that could happen even if the output was overloaded. Could it be an incoming lightning strike on the line ? Clearly, the magneto is disconnected until turned - although a high transient voltage would make short work of that !
In any event the bell & capacitor would be first casualty. That said the bell capacitor did look a bit cooked also ?

Rog
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Old 12th Jun 2022, 9:00 am   #27
petervk2mlg
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Default Re: Magneto phone generates no ring voltage

Iím not too alarmed as I pulled apart a good working magneto to check its state.
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Old 12th Jun 2022, 9:12 am   #28
Roger Ramjet
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Default Re: Magneto phone generates no ring voltage

Good move Peter......cannot see clearly on your piccy's so does the coil on the working unit look similar the the blackened coil on the faulty one ?
Rog
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Old 12th Jun 2022, 9:31 am   #29
petervk2mlg
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Default Re: Magneto phone generates no ring voltage

I'll let you guys be the judge.
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Old 13th Jun 2022, 1:31 am   #30
petervk2mlg
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Default Re: Magneto phone generates no ring voltage

Quote:
Originally Posted by Dave Moll View Post
Quote:
Originally Posted by petervk2mlg View Post
Values are 1.7 and 0.4 uF for that capacitor.
Modern equivalents would be 1.8μF and 0.47μF respecively.
Many thanks Dave.
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