Desk Set
"Burled Walnut"
F1 handset
AE dial with brown fingerwhee
Wall Set
"Burled Walnut"
NU handset
BPO dial
Uniphones were sold primarily to independent phone companies, while the 302 was used within the Bell System in Canada. Therefore, they are found with a variety of handsets, ringers and dials that were added based on local need and supply.
The NE T-7 catalog mentions two primary models, the No. 1 desk set and No.2 wall set.
Deskset replacement models were also made with the same shells and only a switchhook to replace earlier sets such as candlesticks, and B and D mountings.
Desk: No. 5 (manual) and No. 7 (dial)
Wall: No.6 (manual) and No.8 (dial)
Uniphones are usually found with the NE #5 dials, but the catalog also shows wiring for the AE #24 and BPO (British Post Office) dials. BPO dials were often made by Siemens and have their name on the fingerstop. These dials were supplied for comptibility with switches used by independents. The T-6 catalog also shows early Uniphones supplied with the now scarce Northern N14 dial.
All were available in black or "burled walnut" (brown with black highlights)
Right: Inside view of No.1, showing B1A ringer, 101A coil and capacitor. Dated 1951.
Below: Inside view of No. 2, showing B1A ringer, 101A coil and capacitor. Dated 1940.
Note the hinge mechanism in the center that firmly holds the shell to the bottom plate. Very useful for maintenance after wall mounting.
Shown left to right:
NF NU F1
NF and NU have a taller, more angular handle than the F1, with a flat ridge down the back. At first glance, they appear identical, but have subtle differences.
The receiver caps on all three are different, but have the same threads so can be interchanged. NU and NF have a similar cross-section, but the circular hole pattern is tighter on the NU. The F1 cross section is smoother and not as tall.
Contact springs are different, depending on the receiver capsule used (see 2 styles shown below).
The cavity casting is the same for the NF and NU, but different style springs are used for the two capsules. Although both NF and NU will take either spring set, so either capsule may be used, I have never seen a NU handset with the earlier capsule.
The cavity and springs for the F1 were apparently simplified for manufacturing economy.
The NF uses a 2-piece transmitter cap. The black plate with hole pattern is an insert, similar to the one used on the E handset transmitter.
All models use the same F-style transmitter elements that were used in both Northern and Western late E and most F-model handsets.
Early NF handsets used a D 96337 capsule (left).
Later NFs and all NUs and most F handsets used the HA1-style capsule (right).
The D part number suggests it was a design model and not intended for volume manufacturing. The diaphragm is held on by magnetic attraction only.
The HA1 is a sealed unit. The circular contact symmetry means the capsule does not have to be properly physically aligned when installed.
The lower photo shows the D 96337 with diaphragm removed.
