Western Electric 202: Won't dial or transmit. HELP

[skolpas]

I have a WE 202, no subset.  It has a D1 base and an F1 handset.  I get a dial tone.  I cannot dial; the dial tone persists.  If I call with another phone, I can hear on the receiver but can't transmit. The phone was already converted to a modular jack line.

My WE500 and WE302 both work perfectly.

I have attached a photo of the interior wiring.  Can anyone see anything wrong?

[unbeldi]

Well, to be honest, you're probably not going to find many people here helping to hot-wire such a phone.

Your phone needs a subscriber set, or subset. The subset contains the induction coil and capacitor to make a complete telephone. It would usually also contain a ringer.

Quick-buck sellers pitch phones on eBay without a subset and with a modular cord, all the time, sadly.  But it doesn't work very well at all, and it may damage the receiver element in the handset.  Western Electric always explicitly stated that direct current (DC) must be kept out of the receiver, for good reason.

The appropriate subset for your phone is a 684A or 584A, depending on the level of voice quality you want to achieve.

[Doug Rose]

Welcome to the Forum. This diagram is for a #5 dial. Just use the same screw terminals on your #6 dial. They are in different locations on the #6 but are marked. Extra caution with a #6 dial as the screw terminals are close to the metal. Make sure no wires are touching the metal base or any wires are touching accidently. The yellow from the line cord should go to the same postion on your jack as the green wire or just jump a wire from the green to the yellow inside the phone where the line cord terminates on the left terminal strip....Good luck....Doug

[vinhvinny]

Is it true that only 202 with original E1 handset can be damaged without subset? The new and  improved F1 is not susceptible to this damage?

Thank you for your help. 

- vinhvinnynow

[Ktownphoneco]

Any telephone set which doesn't contain an induction coil and condenser / capacitor requires a sub-set, and the receiver in an E-1, F-1 or G series, will most likely be damaged.    Plus the loud snapping in the receiver isn't particularly good for your ear drums.      Unbeldi's advise is good advise.

Jeff Lamb

[WEBellSystemChristian]

I had a 1934 D1 connected to our home phone line without a subset when I started collecting. It worked well after I made a couple calls on it; I'm just glad and surprised nothing was damaged.

[unbeldi]

Is it true that only 202 with original E1 handset can be damaged without subset? The new and  improved F1 is not susceptible to this damage?

Thank you for your help. 

- vinhvinnynow

The receiver (speaker) element is an electromagnet that produces sound by moving a ferro-magnetic diaphragm at the frequency of sound. The correct reproduction of sound, with only minimal distortion across the frequency spectrum from ca. 300 Hz to 3500 Hz, depends on the exact geometry of the diaphragm and its position with respect to the magnet when no current flows through the receiver. The magnet is typically designed to have a permanent magnetization bias already when no current flows.

This forces a slight curvature in the diaphragm which the engineers took into consideration when they optimized the frequency response of the whole handset. In particular the goal was to eliminate the inherent component resonances to reduce loud pops and noise, which were very prominent in earlier design before the F1 handset. The response of the human ear has an integration effect that doesn't scale linearly with the loudness (peaks), but with the rate of change at the onset of pops and clicks.

When introducing a flow of DC current in the receiver, as when 'hot-wiring' a phone without subscriber set, the current introduces an additional electromagnetic bias that distorts the diaphragm. In addition, DC flow can permanently change the magnetization of the receiver core, depending on the polarity either enhancing it, or weakening it over time. When the receivers were manufactured, the magnets were over-magnetized in the factory and subsequently de-magnetized to just the right amount for optimum response, individually for each receiver.

I am trying to express that these instruments are not just crude old devices that work any way one wishes today.  First of all, they are long past their designed lifetime, are on borrowed time, and there is no reason to subject them to abuse and potential destruction by ignoring the design criteria.

The exact design considerations for the F1 handset are documented very well in an article in the Bell System Technical Journal:

• W.C. Jones, Instruments for the New Telephone Sets,  BSTJ 17(3), 338 (1938).
• E. H. Colpits, Scientific Research Applied to the Telephone Transmitter and Receiver, BSTJ 16(3), 251 (1937)

Similar consideration existed for the E1 handset, however, the science was less sophisticated in the early 20s and the development of magnetic materials less advanced.