I'll be the new owner of a 5302

[Kenton K]

Caps in parallel will increase their value. So two .5mf caps in parallel are equal to one 1mf cap. This allows more current to flow through. Caps in series will decrease their capacitance.

Resistors in parallel will decrease value.

KK

[benkeys]

It's been so long since I thought about caps in vintage electronics I couldn't remember.. What would be a suitable voltage for a phone capacitor?

[Kenton K]

I believe 250V and up. I'm not sure though.

KK

[Phonesrfun]

250 is the norm.  It allows for a margin of conservative safety.  You probably don't want to go below 150 volts.  75 to 90 is the normal ringing current voltage.


To the more knowlegeable than I:


Since on POTS lines the ringing voltage is superimposed over the DC voltage, does the cap see 48 volts plus 90 volts AC, or is the 48 volts a base-line where the cap only "sees" the 90 volts?  (Assuming DC is 48 and ringing is 90 VAC)


In other words does the cap see a peak positive of +42 volts and a peak negative of -132 volts, or just +/- 90?

[benkeys]

I went to RadioShack and got a 1 mfd metalized film capacitor rated for 250 volts. It was a 2.00 capacitor. It made a nice improvement on the ring. While I had it open I took a video of it ringing with the extra cap and without the extra cap. I also took pictures of all the dated components. It has an HA1 receiver element dated 1953 and a F1 transmitter element dated 1948. A 5H dial dated 1952. 101A induction coil dated 1952 and the base is also dated 1952. The ringer is the oldest part, dating 1940. The orange ink means refurbished correct? Which means the 304 was likely converted to a 5304 in 1952?

[unbeldi]

The 5300s were made starting second half of 1955 until about 1964 or 5.
Everything but the housing and some handsets were reused components that had come back to the distributing houses.

Look for a white (1955-1958) or green (>=1959) date stamp on the housing by the inside edge in the front, or front side of the housing. That is really the only indication of when the set might have been assembled.

[benkeys]

The rest of the images and a link to the video. I had to put it on my facebook since it wasn't compatible with google docs,even after changing it to a mpeg file. https://www.facebook.com/video.php?v=10203790337013715&l=4121457664220446862
I looked all over on the bottom side of the housing and could not find any date at all. Only seen a 2-C molded into the plastic back where the switchook would sit.

[unbeldi]

250 is the norm.  It allows for a margin of conservative safety.  You probably don't want to go below 150 volts.  75 to 90 is the normal ringing current voltage.


To the more knowlegeable than I:


Since on POTS lines the ringing voltage is superimposed over the DC voltage, does the cap see 48 volts plus 90 volts AC, or is the 48 volts a base-line where the cap only "sees" the 90 volts?  (Assuming DC is 48 and ringing is 90 VAC)


In other words does the cap see a peak positive of +42 volts and a peak negative of -132 volts, or just +/- 90?

Superimposed ringing voltage indeed means the alternating voltage oscillates about the DC offset. But it was by no means universal, because some systems sent ringing as pure AC, while restoring the DC bias between the ringing periods.  However, this makes it harder to detect an answer condition. In superimposed ringing answering can be detected easily also during ringing.

So this does increase the voltage specification for components.  Furthermore, the 90 Vac specification is an RMS (root-mean-square) value so the components are actually subjected to  90 * 1.41 = 127 V, the peak voltage of the cycle, plus the DC bias.  In addition one must add some safety margin.

[benkeys]

My final question is, does anyone know what the REN is for the 5304 or 304?(keep in mind I added the 1 mfd cap) As i'm curious because I do not want to exceed the 5 REN my modem can handle. Seeing as a I a 5304, 500, 554 and 2500 and all but the 554 is hooked up. I know the 3 other phones have a REN of 1. I also have 2 cordless phones but they both have a REN of .001 or close to that.

[unbeldi]

My final question is, does anyone know what the REN is for the 5304 or 304?(keep in mind I added the 1 mfd cap) As i'm curious because I do not want to exceed the 5 REN my modem can handle. Seeing as a I a 5304, 500, 554 and 2500 and all but the 554 is hooked up. I know the 3 other phones have a REN of 1. I also have 2 cordless phones but they both have a REN of .001 or close to that.

The 5304 and 304 are electrically equivalent to a 302 in bridged ringing arrangement.
The REN value of a 302 is around 1.2 to 1.3, according to my measurements with standard telco equipment.  See here:  http://www.classicrotaryphones.com/forum/index.php?topic=12662.msg133038#msg133038 for more details.

PS:  when I wrote this I already had forgotten that the ringer in your set was switched. So you REN value is higher and you might consider adding another 0.5µF capacitor in parallel to the existing one, or simply swap in a 1µF.

[andre_janew]

Now that you've made the ringer louder, what next?  How about swapping out the F-1 handset for a G-1 handset?  That should make others easier for you to hear!