Author Topic: AE Railroad Telephones  (Read 9041 times)

unbeldi

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Re: AE Railroad Telephones
« Reply #45 on: November 12, 2015, 09:42:40 AM »
Yes, I was watching that.   This one still has the Type 41 handset, and that leads me to believe now that this type was made even before 1960.   One could follow AE's tendency to number phones by their year and assume the same for the Type 60.

I think that's a Type 25 anti-noise handset but it doesn't change the argument.

I think the Type 60 was available in 1950 because it appears in documents (CAT 1712 Replacement Parts For Monophones) that predate the Type 51 dial.

Jack

I don't know whether AE made a 41-type handset with a switch in the handle.  If not, it could certainly be a modified type 25 handset, but the standard one would not be compatible with this circuit.  So, either it is a modified type 41 or a modified type 25, or some other type that isn't in the catalogs accessible.


Is this 1712 parts catalog available anywhere?
« Last Edit: November 12, 2015, 09:48:37 AM by unbeldi »

Offline Jack Ryan

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Re: AE Railroad Telephones
« Reply #46 on: November 12, 2015, 06:08:28 PM »
I don't know whether AE made a 41-type handset with a switch in the handle.  If not, it could certainly be a modified type 25 handset, but the standard one would not be compatible with this circuit.  So, either it is a modified type 41 or a modified type 25, or some other type that isn't in the catalogs accessible.

I didn't look at the compatibility issue but the shape makes it not a Type 41. What is the compatibility issue?

The Type 25 didn't seem to last long - the Type 27 (based on Type 38) remained in service and was available after the Type 25. Don't know why.

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Is this 1712 parts catalog available anywhere?

Isn't it one of the TCI reprints?

Jack

Offline Jack Ryan

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Re: AE Railroad Telephones
« Reply #47 on: November 12, 2015, 06:13:51 PM »
Apparently CAT 1712 Replacement Parts For Monophones is mine.

Here it is...

Jack

unbeldi

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Re: AE Railroad Telephones
« Reply #48 on: November 12, 2015, 06:57:09 PM »
Thanks much for the catalog, Jack!
Interestingly, it list the handset for the Type 60 as being a Type 41.  But then, the Type 60 listed in that catalog has the AE40/50 circuit, going by the induction coil number.  So this is indeed the "civilian" version of the Type 60, which did not need a special handset.

For the railway system, the Type 25 handset is incompatible, because it has the wrong push button.  The Type 25 has a push-to-listen, release-to-talk button, which places a short across the transmitter when pushed.   You can't have that in the L-658 railroad version. That requires to complete (close) the transmitter circuit with the transmitter and place a resistor in the receiver circuit.  If a Type 25 handset were used, it would create a short circuit discharging the battery directly across the induction coil, with has only a couple ohms resistance and would kill the battery in short time. In addition, the battery has a very low internal resistance of less than an 1 ohm likely, so it would short circuit the induction coil and withdraw audio-frequency energy from the speech circuit, achieving the opposite of the intended effect.

Offline Jack Ryan

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Re: AE Railroad Telephones
« Reply #49 on: November 12, 2015, 07:20:13 PM »
Thanks much for the catalog, Jack!

You're welcome.

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For the railway system, the Type 25 handset is incompatible, because it has the wrong push button.  The Type 25 has a push-to-listen,

I have never opened a Type 25 handset but it looks like a changeover switch to me - just what a Type 60 needs. There are no instructions on the handset either. Some time I'll have to open one.

Not shown in that catalogue but some Type 25 handsets have a "spitcup" transmitter cap like the AE 34A3B handset.

Jack