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Who do you think made the best magnetos?

Started by Holtzer-Cabot, October 27, 2016, 07:01:33 PM

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Holtzer-Cabot

Quote from: unbeldi on October 27, 2016, 10:26:17 PM
This shows perhaps the point at which the "size revolution" in magnetos started.  This is from a 1934 paper in the Ericsson Bulletin, that shows the old versus the new generator when cobalt-chrome steel was introduced for magnet material.
I'll find the exact reference tomorrow.

Note that these generators even incorporate the ringer internally.

Just a few years later, Ericsson used the new Al-Ni-Co alloys that had even higher flux-densities, more later...


Ref:  E.Bul. 1934(4) p44, Combined Magneto Generator and Bell for Portable Testing Sets
Wow! I never knew they made a magneto with a ringer built in!
Western Electric - A unit of the Bell System and main supplier of AT&T since 1882! -15 year old phone collector!

Holtzer-Cabot

Quote from: unbeldi on October 28, 2016, 09:56:17 AM
Yes, it was used in several wood wall sets for rural service.

Here is a diagram of the NECo 41 from one of the NECo catalogs.  I think these were scanned by forum member Jeff Lamb.  He confirmed to me at one time, that these generators were actually made by Northern Electric, when I was wondering whether Western Electric ever actually made their own, because the WECo parts don't have a regular WECo catalog number, but KS-numbers.  BY that time, Western Electric in the US surely could not have had a high demand for magneto instruments, while in Canada this was still very common equipment.

In any case, from this we see that the crank handle is quite different.

In both cases, Western Electric and Northern Electric, this magneto apparently first appeared in the early 1950s, at least by 1953.  It is not present in the 1940s NECo catalogs, and not in the WECo Catalog No. 10 of 1950.
Yep! And I do think they were Northern Electric, as I have never seen one in a Western Electric set, probably because as you said, magneto service in the U.S. wasn't in high demand. I wonder how long Canada used magneto sets. So would my magneto be a Stromberg-Carlson? The crank handle on mine doesn't look like a NE. When I got it, it was frozen, so I used some 3-in-1 oil and it works great now!
Western Electric - A unit of the Bell System and main supplier of AT&T since 1882! -15 year old phone collector!

dsk

Not necessarily the best, it fits where std Antwerp dial fits, and was used by at least Elektrisk Bureau (Norway) and L M Ericsson (Sweden)

Never had any problems with this type, but I am not happy with nylon gears.  (That comes more to feelings.)

Ill guess I stick to Unbenldis suggestion of Siemens, as the best ones.

dsk

unbeldi

Well, we have really just begun to explore the world of magnetos here.

In addition, I would caution against the idea that there ever was a "best".
What is "best" ?
It really depends on many factors.

Is it "best" to have a technically advanced instrument that can't be produced cheaply enough in certain quantities to be an economic possibility ?
When produced in small quantities cost is sometimes not the determining factor.

The scale of many European telecommunication administrations was minuscule compared to the size of the Bell System. Even France and Germany had a disproportionately smaller telecom market than Bell did.  In addition, distances between subscriber stations and central offices was in general smaller in Europe than in the US or Canada. Therefore the electrical considerations and requirements for signaling were quite different.

Holtzer-Cabot

Quote from: unbeldi on October 28, 2016, 02:51:00 PM
Well, we have really just begun to explore the world of magnetos here.

In addition, I would caution against the idea that there ever was a "best".
What is "best" ?
It really depends on many factors.

Is it "best" to have a technically advanced instrument that can't be produced cheaply enough in certain quantities to be an economic possibility ?
When produced in small quantities cost is sometimes not the determining factor.

The scale of many European telecommunication administrations was minuscule compared to the size of the Bell System. Even France and Germany had a disproportionately smaller telecom market than Bell did.  In addition, distances between subscriber stations and central offices was in general smaller in Europe than in the US or Canada. Therefore the electrical considerations and requirements for signaling were quite different.
I agree! And by 'best' I mean more like longevity and build quality, how the magnetos hold up over time, and what company made the magneto that holds up best. Also we should discuss the similarities between common mags, such as the WE 48A, or WE mags in general, and compare them to SC and Kelogg mags. Or compare SC and Kellogg, or WE and Kellogg etc.
Western Electric - A unit of the Bell System and main supplier of AT&T since 1882! -15 year old phone collector!

19and41

Would the magneto from the Leich desk sets make it into the realm of the ones mentioned?  As a young kid, I had one and valued it highly.  I also had a magneto of the type pictured on the French phone, with the lever actuation.  It extends into the case about a inch to inch and a half.  It wasn't as practical for fun and games as was the Leich. 
"Any sufficiently advanced technology is indistinguishable from magic."
— Arthur C. Clarke

unbeldi

Quote from: 19and41 on October 28, 2016, 06:50:54 PM
Would the magneto from the Leich desk sets make it into the realm of the ones mentioned?  As a young kid, I had one and valued it highly.  I also had a magneto of the type pictured on the French phone, with the lever actuation.  It extends into the case about a inch to inch and a half.  It wasn't as practical for fun and games as was the Leich.

Sure,  I mentioned it in one of my previous posts earlier.  You are referring to the 900 series.  They could be used as desk phones, as well as mounted on a wall. The cradle was designed to work in both orientations without modification.  The magneto is also of the Alnico variety.  These were actually made into the 1960s.

It looks quite similar to the black LME phone that dsk posted, which also has the wall mounting option.

19and41

Sorry about that.  I periodically check running threads on work breaks, but must've missed the mention.
"Any sufficiently advanced technology is indistinguishable from magic."
— Arthur C. Clarke

dsk

Unbeldi has again a good point, what is a good magneto?

A minimum to be deemed as good should be:

At a comfortable turning speed: I suggest 2 revolutions pr second (120 rpm)
the magneto should put out a voltage of at least 60V at a test load of a 1500 ohms resistor.
The frequency should be in the range of 16-25 Hz

It may be a lot of other specifications to put in too, maintenance, dust-proof?, working temperature, humidity, weight, comfortable to use?, the switch connected to operation, brush-less or not. 

So in this thread will be pretty much impossible to get a definitive answer, almost like whats the best car, wife or ...  The Definitive answer her is mine!  ;)

dsk  ;D

AE_Collector

#24
Quote from: unbeldi on October 27, 2016, 10:45:00 PM
In the US, it was Leich again in the 1950s (1940s?) where they picked the idea up in the 900-series magneto phones.

All of the Leich 901 Convertibles that I have seen are dated in the early 1950's through maybe 1957. They likely were made later than 1957 but I haven't personally seen any that "new" nor have I seen any dated in the 40's.

Terry

unbeldi

Quote from: AE_Collector on October 29, 2016, 12:07:00 PM
All of the Leich 901 Convertibles that I have seen are dated in the early 1950's through maybe 1957. They likely were made later than 1957 but I haven't personally seen any that "new" nor have I seen any dated in the 40's.

Terry

Thanks for the early time frame.  I haven't seen any dated in the 1940 either, but wanted to keep the possibility open. It is very hard to date Leich equipment since we have so few catalogs.  I think I have only one from ca. 1938.

The 900s are still listed in the 1957 Graybar catalog, in some 1960s AE catalogs, and even in 1975 in the GTE-AE catalog.


AE_Collector

Quote from: unbeldi on October 29, 2016, 12:29:09 PM
The 900s are still listed in the 1957 Graybar catalog, in some 1960s AE catalogs, and even in 1975 in the GTE-AE catalog.

Wow....1975! Is it possible they still made the odd batches of them in that time frame or maybe they get left with a large stock of them and still sold low numbers of them by keeping them in the catalogs. When was it that the last rural system went automatic....was that "Bryant Pond"?

Terry

unbeldi

Quote from: AE_Collector on October 29, 2016, 12:57:18 PM
Wow....1975! Is it possible they still made the odd batches of them in that time frame or maybe they get left with a large stock of them and still sold low numbers of them by keeping them in the catalogs. When was it that the last rural system went automatic....was that "Bryant Pond"?

Terry

Yes, 1983, by some accounts.

dsk

The last magneto-phones made in Norway was made in 1967. The last service was officially closed in 1990, but had some summer seasons in use after that. 
dsk

unbeldi

#29
Here is the Al-Ni-Co generator in the Leich No. 26 Bell Box and the No. 86 wall telephone, that is often dubbed as the "Beehive".  I think it is very nice package, but the Bakelite housing they put around it was extremely fragile. The Bakelite is very thin, and you can see fracture lines in this set. It was a *blank* to glue back together from almost 20 pieces.

Contrary to the housing the Bakelite base on which everything is mounted is very sturdy, it actually used to mount the unit against the wall, but it is convenient to take pictures with everything sitting on top of it.

I believe this package was first listed in a sales catalog in 1938, but without pictures. IIRC, pictured were still earlier generators, and this was only included in the price list. Therefore, I am assuming that to be the approximate introduction period. I don't think any other American manufacturer had an Alnico generator at that time, but I like to find out if anyone else did.