Princess finally added to my collection

[AL_as_needed]

Finally got a princess to add to the ranks for all of 17$. Low and behold, its a 12-60, 701B and seems to be about all matching say for the handset elements. Didnt come with the external ringer though 

Upon reading up on these, according to pau-f.com, these didnt have the lead weight until '62. Was this something that was added to the earlier sets as they were serviced?

Also,is there an LED replacement bulb compatible with the standard WE socket? I'd like to use the light feature but do not want anything getting too hot in such a confined space. I also figure if the LED route is possible, may be able to run it off line voltage rather than deal with a wall-wort.

[unbeldi]

None of the 701B sets had a ringer.  For this an external ringer box was installed.
Yes, lead weights were invariably added when refurbished, or when the customer complained.

LEDs really don't work very well here, because these sets have a switch to run the light at half brightness when on-hook. This can't be easily duplicated with a simple LED in the circuit that is used for this.

[AL_as_needed]

LEDs really don't work very well here, because these sets have a switch to run the light at half brightness when on-hook. This can't be easily duplicated with a simple LED in the circuit that is used for this.

Ah, so there is a voltage step-up/step-down when the handset is on or off hook? They do make "dimmable" LEDs, but likely not small enough to fit into the phones socket. I have had flashlights at work that have Hi-Lo beam sort of functions, but those actually have a small chip set to accomplish that.

[unbeldi]

Ah, so there is a voltage step-up/step-down when the handset is on or off hook? They do make "dimmable" LEDs, but likely not small enough to fit into the phones socket. I have had flashlights at work that have Hi-Lo beam sort of functions, but those actually have a small chip set to accomplish that.

It is a current-limiting resistor of 27 Ω that is shorted by the hook switch when the handset is lifted.   27 Ω is just exactly the hot-resistance of those bulbs when run at 250 mA from the 2012A transformer.  So this results in one half of 1.75 VA being wasted in the resistor.

[AL_as_needed]

It is a current-limiting resistor of 27 Ω that is shorted by the hook switch when the handset is lifted.   27 Ω is just exactly the hot-resistance of those bulbs when run at 250 mA from the 2012A transformer.  So this results in one half of 1.75 VA being wasted in the resistor.

If that is all the difference between Hi-Lo, I think a flashlight LED or an automotive LED (like something for a gauge cluster) could work within that range. For example, they have MAG Lite LED kits for standard MAG flashlights, which range from 2,4, and 6 1.5 cell models, and all can be refitted with the same LED kit. Automotive gauge clusters are also dimmable from 12v down to I think 6 or 8v.

[AL_as_needed]

https://www.superbrightleds.com/cat/miniature-wedge-base/

LED with similar or same base specs as stock GE/WE bulb. As per the following web page:

http://ericofon.com/catalog/parts/princess/led.htm

[poplar1]

http://www.oldphoneworks.com/princess-phone-led-bulb-wedge-base.html

[unbeldi]

While I am sure these work in full brightness, I doubt they can be dimmed in the existing circuit of the 702B.   These LED's have a rather high impedance and adding 27 Ω into that circuit won't make much difference.
Haven't we discussed this before somewhere here?

[AL_as_needed]

You would be correct unbeldi, "dim" wouldn't really be so with a small drop, of course the brightness would also be directly related to the incoming voltage.

I did do a search earlier before starting this thread and did not find anything specific to princess. There was one or two on pre-LED trimlines however that I read through,  but those use line voltage and a smaller bulb.


Im going to try a few things in the way of LEDs and power supplies and see where it goes. As FDR once said "...bold, persistent experimentation. It is common sense to take a method and try it. If it fails, admit it frankly and try another. But above all try something."