D-1 bases - different markings?

[Bill]

I had a couple D-1 bases out today to begin some refurb, and noticed something I hadn't seen before.

In the left half of the photo, the base says "D1 USA" on the neck, and nothing on the lower edge of the housing. The base on the right says simply "D-1" on the neck, and "Western Electric Made in USA Patent xxxx Patent Pending" on the lower edge.

Aside from this, the two appear identical - but what do the differences signify?

Bill

[rdelius]

The later zinc sets have the USA markings and no patents
Robby

[deedubya3800]

What were the earlier ones made of?

[rdelius]

aluminun
cant spell it

[Bill]

Neither one is attracted to a magnet, so perhaps one is zinc-coated aluminum while the opther is uncoated aluminum?

Bill

[rdelius]

The newer one is zinc with no patent information like a 302 set .The older set is aluminum. the keyway on the cradle where it fits the base is a different width also.Note the difference in weight.
Robby

[deedubya3800]

I so totally didn't notice the difference in weight, but I got a 1931, with the patent number, and my aunt has a 1936, without. The next time I go down there I'm gonna have to take mine and my kitchen scale. I am preparing right now to be blown away!

[Bill]

I dunno, Robby. The two D-1 bases shown in the picture in the first post weigh exactly the same amount - 12 1/2 ounces.

I'm not sure why Western Electric would make a telephone base out of pure zinc. I'm no physical chemist, but I would think that pure zinc would be a bit brittle, not to mention expensive. On the other hand, I could imagine them adding zinc plating to the original aluminum housing, to improve some property like paint adhesion. So perhaps this plating is the zinc you are referring to.

Bill

[rdelius]

When we used to gold plate 202 sets we did notice a difference in weight between the older and newer housings.It was most noticeable when they were totally stripped of all components.It is possible that the switch in metals came later than the marking changes. Find a very late example 1937 or so and see how heavy it is. It might be possible that the change happened so the 302 and the 202 could use the same metal mixture.302 sets are mostly zinc but I have a 400 series set that seems to be lighter weight even though it is bigger so i suspect it is a aluminum alloy
Robby

[wds]

I purchased a book from Ebay, written by Western Electric, 1927.  It talks about all the metals used in their equipment, and what part of the world the materials come from.  The section about Aluminum mentions being used in diaphragms, and the transmitter and receiver cases, but doesn't mention phone bases.  Would these Aluminum bases have been manufactured before 1927?

[Sargeguy]

The D-1 was manufactured in the 30's.  The B-1 started in 1928 or so.