I was lucky enough to pick this radio up at the Goulburn HRSA meeting this Saturday. Valve lineup 80 ,42, 75, EK2G and 6U7. BC and SW.
Seyon is made by the Noyes Brothers. The brand is their name in reverse. This is a astoundingly nice set. Very large and imposing.

Photos uploaded.

Chassis looks a bit like AWA Radiola

That's a really nice looking radio... Very schmick cabinet.
Looks quite sizeable too.... What are its dimensions Carl?

It's about 80 cms by 60 by 60. Yes it's quite sizeable. A great performer as well.

Ok a question. There is a Arial terminal and two terminals above it. What are they.

My guess from top to bottom is earth terminal, distant antenna and local antenna.

Another possibility is the aerial 1 and 2 terminals are for the two legs of a dipole antenna, seeing as the radio is dual wave.
I have have an STC 632 (triple wave) with the same connections. Have often wondered about them so will be interested in what is decided for the Seyon.

The black one has EARTH printed next to it, if you look carefully.

The others say AERIAL 1 and 2, so either what Brad said, or if the unit has shortwave (can't tell from the dial), then separate antennas for each band.

Also, there's a magic eye tube that you forgot to mention in your valve list.

Yes, medium wave and short wave aerials.

Just another thought. Thus set is extremely well built but by the look of the carry handles and the actual size could they have been trying to save money by using a easy to get packing crate. Just remember 1937 is post depression and pre ww2. Astor did the same with some of their consoles by using planks off old crates. Again to save money.

Seyon: Is Noyes Bros. Backwards. Found a cycle battery in one of theirs where the warranty ran out in 1927 & it still had some voltage.

Seyon: Is Noyes Bros. Backwards.

See post #1, second line.

Re A1, A2 and E connections, went right through 1937 AORSM circuits looking for explanations of the use of A1, A2 and E terminals.

The best explanation is given in some STC circuits. These shows A1 and A2 connected with two wires marked "Doublet". A link is shown between A2 and E, and this is marked "Link removed for loop connection". Will submit a photo for Brad to consider for posting.

My interpretation of this is that doublet means a balanced feed, such as is provided by a loop antenna. The A2-E link would be removed as it is not needed for a balanced feed. Maybe such a balanced feed could be used for a dipole antenna or other balanced antenna. The link would be left in place for the usual longwire aerial and earth set-up.

No explanation is given as to impedance or whether a balun of some sort is needed. (By the way for television aerials, a balanced feed is the old 300ohm impedance TV tape, while an unbalanced feed is co-ax. A balun is needed going from balanced to unbalanced or vice-versa and is very important for TV, but not quite so important for radio receivers especially MW, though signal loss will occur). But the trade very likely knew what to do.

The terminals are not only marked A1, A2, E. The following can also occur on circuits:

A, RE, Earth; A, unmarked, E; A, A1, E; A, A1, E1; unmarked, T. Aerial, Earth; Ant., Doublet; A, E1, E.

A, WT (wave trap), E apparently means a radio with a wave trap to filter out a beacon signal or some such.

Sometimes, where a radio has only two terminals marked A and E, the E terminal is not connected to the chassis but to the aerial coil alone. I would guess that such terminals can make a balanced feed, as some are on battery radios which might use a loop. An earth link connection may or may not be provided for optional use with the usual unbalanced longwire aerial and earth. Sometimes E is connected to chassis with a capacitor.

So the variations are many.

There can be errors in AORSM circuits, so everything needs checking. In the case of my (1938) STC 830, the Code label on the back of the chassis (which has the model number and serial number as well as a diagram showing the valve layout and identification of all the various connections), shows three spring terminals whereas it has only two and an earth link on the chassis. Conversely the STC 1030 (also 1938), for which I acquired a photo from the net, shows two spring terminals on the Code label, but three on the chassis. The 1938 STC circuits, as opposed to the 1937 mentioned above, don't have the doublet/link explanation.

By the way, Seyon is not there.

STC 5033B Circuit Diagram

In the case of my (1938) STC 830

Speaking of the 830, Radiomuseum lacks photos of that model. Maybe you could provide some?