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Problems with WE 500 C/D 425B network?

Started by RDub, October 26, 2016, 04:40:34 PM

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RDub

At first ringer not functioning. Found info stating "remove Blk wire from (G) and reconnect to L1. Ringer works. Here is the problem. When phone is ringing, I lift the handset off the hook the ringer does not stop. Also,  I can hear the ringer electrical pulses through the receiver. Side tone must be working because I can blow into the transmitter and hear that just like on a functioning phone. No dial tone. Engaging the cradle shuts off the receiver and transmitter but the ringer keeps ringing. I removed the dialer and leads to see if any change. None. I tested continuity on hook and dialer switches. They all function as designed.
Is the network maybe bad! Is there a way to test it? I used an ohm meter to trouble shoot a bad 101A induction coil awhile back. Can that be used to trouble shoot the 425B? Seems way more sophisticated than the 101A. Help!

I have included the schematic I was using. Hopefully I attached correctly. RDub...

jsowers

First, thanks for doing your research before asking your question. You fixed one problem that way.

When you checked the continuity of the hookswitch, did you test it on-hook and off-hook to see if all the switches made and broke contact?

Have you gone through the schematic you posted and made sure all the wires are connected to the network on the correct screws and nothing is shorting out? Sometimes those spades can touch another screw or if someone used bare wire, it could be touching another screw.

A picture of your phone's network taken from above might be useful too.

It sounds like the ringer is OK, or it wouldn't be ringing at all. Let us know if you get it working, and good luck!
Jonathan

Phonesrfun

It certainly could be a bad network, but I would double check the wiring connections before assuming the network was bad.  Somehow the DC path is not getting through the primary circuit to trip the ringing or to create an "off-hook" condition to get dial tone.  Perhaps a winding on the coil or a varisistor bad.

Yes, the 425B network is much more involved than a 101-A induction coil.  Essentially, there is what amounts to a 101-A in the 425-B, but a winding or two more on the coil and a few extra components thrown in for better antisidetone and DC loop compensation. 

Unfortunately, if something in the 425B is bad, you pretty much cannot fix it.
-Bill G

Ktownphoneco

#3
"RDub" ..  You may want to trace the set's circuit again.    I'm not sure if I'm reading your schematic correctly or not, but it appears to me that there is a discrepancy on at least one terminal connection which travels through the hook switch,connecting "LINE 2" and terminal "C" on the Network.   On your diagram, you have indicated that when the set goes "Off Hook", terminal "C" on the Network, will, through the hook switch springs, connect to terminal "L-1" ( Line 1 ) on the network.      According to the schematic I downloaded from the TCI Library, the circuit connection which is closed or created, when the set is placed in the "Off Hook" position, should connection "C" on the Network, with "L-2" ( Line 2 ) on the Network.     That would be the top two spring switch points, closest to your label "HOOK SWITCH".
I'm also attaching the schematic diagram I downloaded from the TCI Library.

Jeff Lamb

Attached Schematic Diagram provided, with thanks, by the technical library of Telephone Collectors International  (TCI)

RDub

Thanks guys for your comments. Ktown your schematic is 100%. The one I used was lacking one wire on the hook switch and wire colors were not accurate. Well, I traced the wire leads and got them in order. I think the problem now lies with the dialer pulse switch. According to the schematic it should normally be closed. Mine stays open and when the phone is ringing I have to jumper the blue and green leads to stop the ringer. Also, when I do that I get tone through the handset. I can achieve the same by slightly rotating the finger wheel which closes that switch. Dialing the numbers gets me nothing on my BK1045. (?)
I did take apart the dialer to clean as it would not return home. Is there a timing issue when reassembling? I didn't see that. See 1st photo. (pulse switch) You can see the cam and the follower right behind it. The follower holds the switch open. Is that correct? Why no digit readout on the BK?
RDub

unbeldi

#5
The pulsing cam is misaligned in your dial.

This is the cloudy gray oval cross-section cam that operates the pulsing spring. It needs to be rotated ca. 180 degrees from its pictured position.
That way it will push the spring contacts together to close the switch.

When reassembling you need to to position it correctly. I think you removed the top plate that keeps the gears in place ?

PS: here is a picture.

Ktownphoneco

RDub   ...   Dials, generally speaking, should be calibrated to provide pulse signal at the rate of 10 pulses per second (pps).    The acceptable rate is between 8 pps and 11 pps.    I calibrate dials at 9.6 pps, which puts them in the middle of the acceptable range, allowing for slight increases and decreases in speed without causing mis-dials.      The pulsing springs, while in the process of dialing a single digit, should remain open (break period) of 60% of the time, and closed 40% of the time.    I've found that pulse spring break which exceeds 65%, will most likely start producing mis-dialed numbers.

The pulsing cam on you dial is nylon, and sitting in the "rest" position, the high point on the cam should be positioned around the 1:00 o'clock position, to 1:30 position in relation to where it touches the driven pulsing (bottom) spring.      When positioned correctly, it will hold the 2 pulse springs together in the closed position.
Grasping the nylon pulse cam at the bottom with a very small screw driver and exerting upward pressure "CAREFULLY", will usually start moving the cam off the shaft.    Finger nails should complete the job.    Re-position the nylon cam with the high point or lobe, at about the 1:00 o'clock position, moving it ever so slightly left and right, and you should feel the cam position itself with the splines on the shaft.   Make sure the cam is "square" with the shaft, and push the cam onto the shaft, being careful to lift the shoe on the bottom pulse spring so it clears the cam.   Slide the cam down the shaft until it stops.
Try the dial and see if everything appears to be functioning correctly, and the pulse springs are closed (touching) when the dial is sitting in the rest position.   If everything looks correct, re-install
the dial.

Jeff

I've added some information to one of your pictures here :

RDub

Guys, the phone functions as it should after retiming the pulse cam to your specifications. Tone is there as well as digits on the BK1045. I chose to loosen the gear assembly and adjust rather than pry off the plastic cam. Thought with my luck I would have cracked it doing so. May have to adjust the cam a little more. I maybe slightly off from your picture reference. Should I be using the governor housing as the 12 o'clock reference point?

One more question. I notice this with all of my phones when connected to the BK1045. If you have the receiver to your ear, while in a ringing cycle, you can hear electrical pulses from the ringer through the receiver at the moment you lift the hook switch. I thought that would be muted some how. I guess normally when your phone rings and you grab the handset by the time you put it to your ear that pulsating has ceased. I'll have to call myself and see if it does the same when hooked to the telco line.

Again, thanks all.. RDub :)

Ktownphoneco

RDub   ....   I do this visually, and use the 12:00 o'clock reference position on pulsing "shoe" which extends off the lower portion of the bottom pulse spring based on an imaginary point where a vertical line through the pulse cam and the shaft that drives it, would travel through the pulsing shoe, creating a perfect 90 degree angle.     See diagram.

Jeff

RDub