Author Topic: Automatic Electric 47 Chrome Phone with 4 buttons- also a hold button Very cool  (Read 3004 times)

Offline AE_Collector

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 7474
  • AE 2 - AECo's 1st Self Contained Desk Phone 1925
Thanks for all the pictures Tom. Does it look like the dial has the cast zinc type case rather than the stamped brass case? I think I can see that each dial contact leaf actually has two contacts on it thus it is a Type 51A dial (bifurcated contacts), can you confirm that?

I need the number on the Varistor as well. That is the light gray bobin thing between the hook switch and Induction Coil. It is half hiding under that electrical tape. Should have 3B (12-58) or something like that printed on it where 12-58 is month and year.

And can you see a two letter code on the big condenser? The little one has BP on it on the very bottom row of markings.

Open up the handset caps too and see if they are marked type 41 or 81 and if they have the two letter codes stamped on as well.

Thanks again for all the effort.

Unbeldi: What do you think of this one having cloth insulated wiring inside? That's a surprise for a set with an actual date code 7-57 on the bottom.

Terry

« Last Edit: February 01, 2017, 11:36:37 AM by AE_Collector »

unbeldi

  • Guest
It is interesting that the wiring schematic lists the location as "Chicago".  This is an older diagram. The new diagram showing "Northlake" was not ready yet either.  Since the 47 Monophones were not made before 1949, and the postal rezoning took place in 1943, it is evident that the use of "Chicago" in diagrams or labels is not always significant in the timeline of manufacturing.  But I have seen this with other schematic labels. A set that I evaluated as being manufactured between 1952 and 1957, has a schematic with "Chicago", cloth wiring, #51 (not 51A) dial.

We still don't have a clear dividing date between cloth and vinyl wire insulation. It could well be as late as 1957. The sets from Northlake that I have seen have vinyl wires.

It appears that Tom's mounting cord has vinyl insulations. (not Tom's, but his phone's  ;D).

At least by second half of 1957—but I suspect earlier already, possibly 1955—the receiver and transmitter capsules in all Type 41 handsets should be of Type 81.

« Last Edit: February 01, 2017, 10:14:55 AM by unbeldi »

Offline AE_Collector

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 7474
  • AE 2 - AECo's 1st Self Contained Desk Phone 1925
Speaking of plastic insulated internal wiring, it seems as though there was a change in it as plastic insulation progressed. Sort of like the soft plastic and newer ABS plastic phone housings. Early plastic insulation colors seem somewhat dark and are frequently covered with white mildew (?) like soft plastic phone parts where as the plastic wiring insulation in the 1959 AE47 posted above and another phone seen recently here has very bright clean wiring.

Now to type 41/81 transmitter and receiver capsules. I wonder if there are any electrical differences, particularly in the transmitters where the physical design never changed. The metal casing only changed in the material, brass and then aluminum. So the type 41 versus type 81 labelling may mean nothing other than keeping the numbering within the right range for the phone (handset type) it was used with.

The receiver capsules did eventually physically change quite significantly where as the transmitter capsules didn't. The earliest AE 80's still used the type 41 style receiver capsules though likely labelled as type 81. This was in the type 81 handset. Before long after the AE 80 was introduced the redesigned receiver capsule with screw terminals on the back were introduced and the handset changed from type 81 to type 810.

I hadn't thought about whether capsules labelled as type 41 were used in AE40's being built at the same time as capsules labelled as type 81 were being used in AE80's on the assembly line. It stands to reason that both phone types would get capsules labelled as type 81 particularly in the case where Northlake was just opening up and type 40 & 50 set production was dropping rapidly and 47's would be replaced by type 87's in the near future.

Terry
« Last Edit: March 01, 2017, 11:51:13 PM by AE_Collector »

unbeldi

  • Guest
Speaking if plastic insulated internal wiring, it seems as though there was a change in it as plastic insulation progressed. Sort of like the soft plastic and newer ABS plastic phone housings. Early plastic insulation colors seem somewhat dark and are frequently covered with white mildew (?) like soft plastic phone parts where as the plastic wiring insulation in the 1959 AE47 posted above and another phone seen recently here has very bright clean wiring.

I suspect AE also used wiring with synthetic rubber insulation, isoprene or neoprene, before the vinyl/PVC insulation that was indeed brightly colored.  Isoprene is dull like natural rubber.

Offline rdelius

  • Hero Member
  • *****
  • Posts: 1889
I thought the resistance of the type 81 and 41 tx capsule were different.On the type 40 set, all the line current passed through it but some is shunted around in the type 80 sets with the veristors in the self compensating version.Type 41 rec capsules have an open sound hole and and are usually brass ,.can differ in impedance.Have found some ww2 vintage that were a high impedance for use with radios that had no output transformer.Type 81 rec had a plastic cover and are  not brass

Offline AE_Collector

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 7474
  • AE 2 - AECo's 1st Self Contained Desk Phone 1925
All of the AECo 81 transmitters are part # D-38363-A. The AECo 41 transmitters are D-38309-A but there are some -B versions as well. So the part number is different but that could be because of the 41 versus 81 stamping OR maybe there is something electrically different with them as well. There appears to have been some use of the "wrong" type in late 47 sets with Type 81 capsules. Maybe it wasn't a serious problem to use the newer type capsules in a phone with the old 40 type circuits.

Terry