A Couple Of Trimline Questions

[19and41]

I have been going over the rotary 1976 dated trimline phone.  I have put the ringer back together and it's functional now.  I had to get a new pre-modular cord for it as it had broken retainers and had beverage contamination.  I see it has a switchboard lamp to edge light the dial print.  Is it supposed to have any additional power source?  it's filament is intact and It has not lit.  The phone is otherwise functional.  I was hoping the new cord might restore the lamp's function.

[G-Man]

I have been going over the rotary 1976 dated trimline phone.  I have put the ringer back together and it's functional now.  I had to get a new pre-modular cord for it as it had broken retainers and had beverage contamination.  I see it has a switchboard lamp to edge light the dial print.  Is it supposed to have any additional power source?  it's filament is intact and It has not lit.  The phone is otherwise functional.  I was hoping the new cord might restore the lamp's function.

Earlier Trimlines never used switchboard lamps for the dial light and just like the Princess, needed an external transformer to power the slide-based incandescent lamp.

2.05 The 220A (MD), 220AM, 2220B (MD), and 2220BM handsets are equipped with a dial light which requires an external power source (2012A (MD) or 2012C transformer) or equivalent 6-volt supply.
The 220C, 220AL, 226A, 2220C, and 2226A handsets are equipped with light emitting diodes (LED) for dial illumination. Power to light these dials is supplied by CO battery over the incoming line and no local power is required. The 220C, 220AL, and 226A rotary dial handsets are stamped LED at location shown in Fig. 5. The LED equipped TOUCH-TONE telephone dial handsets can be identified by the square dial buttons.

[19and41]

Out of curiosity, how was the external transformer connected to the phone?  I am familiar with the princesses' transformer setup, but this phone uses a modular socket and that and the handset cord socket are the only apparent connections.  (And thanks tor the quick response!)

[G-Man]

Out of curiosity, how was the external transformer connected to the phone?  I am familiar with the princesses' transformer setup, but this phone uses a modular socket and that and the handset cord socket are the only apparent connections.  (And thanks tor the quick response!)

I don't know the model number of your instrument but here is a schematic for an earlier version.

[poplar1]

The transformer connects to the  second pair (black and yellow, or white-orange/orange-white) in the wall jack.  When a 4- or 6-conductor line cord is used,  the 6-8 VAC from the transformer will connect to the yellow and black of the 623T line cord jack. (Some Trimline bases have only two wires in the line jack, so the incandescent lamps won't work with those bases.)

A hardwired Trimline uses black and white leads for the dial lamp.

The schematic provided above is only for the handset.

[poplar1]

Here is a wiring diagram from TCI library for using the AD2 or AD3 base.

[19and41]

Thanks all, for the information!  One other question,  I saw mention of LED illumination used in some types.  About when were those made?

[jsowers]

According to this site, the LED Trimlines were first released in the late 1970s. This also coincided with the square buttons on Touch-Tone Trimlines. I'm also thinking the introduction of brown and rust colors on WE Trimlines was also around this time.

http://www.frillfreephones.com/trphhi.html

[poplar1]

           September 1, 1978, the Bell System added rust and chocolate brown to the existing eight colors
           that make up the Trimline product line.

Dialtone, final edition, Sept. 13, 1984 (Employee magazine from the Indianapolis Shadeland plant)