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Weak bell conundrum...

Started by twocvbloke, February 24, 2012, 12:23:52 PM

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twocvbloke

I don't know what it is, but, when I play with my 500s and 2500 on my BT Linesman phone, the bells sound lovely and strong, and very loud even on low, but, I connect them up to the phone line, even just that one (2)500 phone all on it's own, the ringer seems to lose it's strength and sounds weak when turned up or down... ???

Doesn't matter how I fiddle with the bells, the bias springs and all that, the BT phoneline just doesn't seem to ring at the same frequency that the BT Linesman phone does, so, they must have changed something between the 1990's and the 2010s, seeing how BT's hardware doesn't work like BT's hardware... ::)

I don't know, I guess BT just doesn't like vintage phones, they prefer everyone to have electronic rubbish with tone ringers and memory functions that nobody ever uses (at least, I don't!)!!! :D

LarryInMichigan

I believe that it was discussed here before that the British phone systems provide a lower ringer voltage than the North American ones.  When using a British phone here, it is advisable to add a resistor in series with the ringer to reduce the amount of current drawn.  You can try doing the opposite.  On your 500, try bypassing the resistor in the ringer by adding a jumper between the slate and black ringer wires.  Doing so will almost certainly make your ringer louder.

Larry

twocvbloke

Ah, that sounds like an easy job for the two WE500s, the NT2500 I've yet to "map out" mentally as it's network is all laid out very differently to the 425Bs in the 500s... :D

I think I have read about the ringer voltage difference, but that grey matter in my skull likes to forget such things... ???

twocvbloke

Nope, Jumpering between the Black and the Slate wires has muted the ringer completely, the clapper doesn't move, but I can feel it trying to...  ???

That's in the 2500, I haven't tried it in the 500s...

dsk

I have the same problem on the job PBX.
Tried to get more out of it by putting in a 0.5µF in parallel with the one in the network, didn't solve it.

Cant use to much time for experimenting so I just changed to another phone. 

If you disconnect red and slate red of the ringer, and tape those to ends. Replace this with a strap, and test. (Now you should have a 1000 ohms ringer.) You could add a capacitor of 0.5µF or greater between A and K on network.

Don't know about UK ringer voltage, but Germany may use less than 60 V.

80-90V here in Norway.

dsk

twocvbloke

I think ours is about 75-90v, depending on what exchange you're connected to (e.g., the VirginMedia (formerly NTL, Cable & Wireless and Nynex) exchange we used to be on powered the black WE500 perfectly, but the BT one we're on now doesn't), though in this day and age, modern electronic ringers don't care what they get so long as it's an AC current, but I guess it just backs up the need to buy myself a Panasonic phone system... :D

I'll have to try other modifications tomorrow cos I'm falling asleep now (back in a daylight sleeping pattern, for now!! :D ), but it's what I like doing, experimenting with things to make it all work... :D