Western Electric was one of the few companies that could legally build and sell a superheterodyne in the 1920s. However, factory Western Electric sets could only be sold for commercial purposes. If an amateur or home user wanted a Western Electric set then they had to home brew it out of Western Electric components. That is probably the case with my Western Electric set. My set is kind of an ugly duckling from the front panel appearance, but the inside top chassis view is a beautiful sight to behold.
The front panel knobs are small and the layout looks to be a little lopsided. The strange front panel layout was a necessity because of a partially shielded metal chassis. I have seen three or four of these home brewed Western Electric sets and they have all had some type of sheet brass or copper shielding, just like their factory counterparts.
My set is a hybrid of sorts, probably building on the foundations of a Western Electric 4A receiver and a Western Electric 7A audio amplifier. The 4A receiver had three stages of IF amplification and this was found to be more than adequate, so Western Electric came out with the Model 4B receiver that only had two stages of IF amplification. My set seems to match the 4A receiver because it has three stages of IF amplification. The 4A receiver was available in October, 1922, and the 4B receiver was available in January, 1924 (Douglas, Radio Manufacturers of the 1920’s, Vol. 3, 1991). My set could have been built as early as 1923.
Here are a few particulars of my set:
1. It looks like the radio operates on the standard 1920s superhet circuit but there are a few minor differences from other sets. Most of the tubes in the set have their filaments wired in series to obtain the required negative bias for the grids (from the voltage drops of the various filaments). This set has push-pull audio output.
2. The front panel measures 36” long by 8.25” high by .25” thick.
3. Western Electric IF transformers (No. 83 A Ret Coil).
4. Western Electric filter transformer with primary capacitor (I actually don’t know if this is Western Electric or home brewed)
5. Western Electric audio transformers (218A input, 218B input, and 111A output).
6. Cardwell tuning capacitors.
7. Nine tubes total. Six Western Electric 215A “peanut” tubes, and three UV-201-As (should be WE 216A “tennis ball” tubes).
This is a close-up view of the lettering on the side of one of the IF transformers. In telephone applications a “retard coil” is the same thing as an audio choke coil (a coil that has a high reactance at audio frequencies). The 83 A Retard Coil is a very early transformer and I suspect that it could predate the RCA UV-1716 transformer. I have not measured the frequency response of the transformers but Leutz indicates that they peak near 50 KC (Leutz, Modern Radio Reception, 1928, page 114).
Close up view of the variable resistance used to control the volume. There are about forty different wire-wound resistors on the rotary switch. This is the most grandiose and detailed volume control resistance I have ever seen, including the factory Western Electric units.
Schematic diagram of the Western Electric 7A audio amplifier, as copied from page 106 of Leutz’s Modern Radio Reception (1925). The audio output circuitry of my set is wired much the same as this.
Schematic diagram of the Western Electric 4B receiver, as copied from page 56 of Leutz’s Modern Radio Reception (1925). This diagram is different than my set but there are many similarities. As stated before, my set has three stages of IF amplification but the 4B only has two. My set uses the “83-A RET COIL” IF transformers as shown on the 4B schematic. My set has the volume control resistance connected in parallel with the primary of the second IF transformer, but the Model 4B has the resistance connected in parallel with the primary of the first IF transformer. My set has a three-tube push-pull audio amplifier, but the Model 4B has a single tube audio amp. There are a few other minor differences.
This is a view of the end audio amplifier shielded compartment. The 218A input transformer is located in the upper right, the 218B input transformer is located in the upper left, and the 111A output transformer is located in the bottom left. The components in this compartment are very similar to the Western Electric 7A push-pull audio amplifier
This is a view of the center or IF amplifier shielded compartment. The three “No. 83 A Ret Coil” IF transformers are located at the top center of the photo. The filter transformer is located at the top left. The tuning capacitor on the primary of the filter transformer is located on the far left center. The volume of the set is controlled by a variable resistance connected in parallel with the primary of the second IF transformer (the variable resistance is a series of wire-wound resistors selected by a rotary switch). A better view of the IF transformers and the variable resistance is shown below.
This is a view of the front end RF shielded compartment. Depending on the binding posts used, this set can operate from the built-in antenna coupler or an external loop antenna.
Rear chassis view.
Top chassis view. This is a nice looking set from this view. The two coils on the far left (one large and one small) comprise an antenna coupler. The smaller coil can be rotated to change the coupling. The coil on the right is the oscillator coupler. All three coils are plug-in type to accommodate band changing. The band changing feature may date the radio later than 1923, to perhaps as late as 1925 or so. Band changing was not too important in the earliest years of broadcasting, and somebody went through a heck of a lot of trouble to fabricate these plug-in coils! All nine tubes look very impressive in a single line. The grid leak resistor for the second detector is between the fifth and sixth tubes. No wiring at all is visible from the top chassis view. The front panel and base panel are both .25” thick. This was a high quality set for the day!
Front angle view with the lid open.