BT 741 With no hole for cable

[Millay_2010]

I attach some pics.

[AndiiT]

Hi,
Your phone does have a hole for the cable! Originally this phone would have been hard wired and the "Drop wire" would have been routed past the groove on the back plate close to T19 in picture 2.

After the telephones were converted to modern plug and socket working a cut out, the one which you mention, was made in the plastic casing to allow the line cord restraint to be seated there; the line cord restraint itself would sit snugly in the internal chassis cut out underneath the cover retaining screw.

All 700 series telephones, whether wall or table models, were produced with a number of "knock outs" in the mouldings for provision of fitting auxilary equipment such as a Planset base or additional watch receiver etc.

More information can be found Here

Regards

Andrew

[Dave Moll]

Being a wall-mounted instrument, Bob Freshwater's site shows the cables exiting from the front (i.e. bottom) of the 'phone. I can't make out what part of the case you are showing in your first image.

edit: Andrew beat me to it.

[Millay_2010]

Thanks for the replies, i was mostly interested in how the original drop wire exited the chassis, thanks for clearing that up. The reason I didnt think it was GPO was that the cut out was very roughly done but looking closer I can see it now.

I always visit bobs site, but some questions still bug me

Many thanks

[Station X]

It would have been rare for dropwire (copper coated steel) to be taken directly into a phone. It would have been terminated on a terminal block close to the point where it entered the building and a three or four wire cable run from there to the phone. This would have entered a 700 wall type phone through the base plate.

[AndiiT]

Hi,
Graham is correct, I didn't mention the correct termination of the drop wire to a BT52A (or similar) to avoid any confusion that may have occured.

Apologies

Andrew

[davidw]

Some models had a "knock out" in the base plate,under the pcb.

[DAVEHALL]

Originally Posted by Station X

It would have been rare for dropwire (copper coated steel) to be taken directly into a phone. It would have been terminated on a terminal block close to the point where it entered the building and a three or four wire cable run from there to the phone. This would have entered a 700 wall type phone through the base plate.

I have seen on odd occasions "Leader "( wire lead in??) used - similar to black plastic dropwire ( slightly heavier than no 3,on a par with the really old black stuff) , but the wires were pure copper ,and bent easily , from the lightning protector to the phone .

[Station X]

I know the wire you mean. In the days when "drops" were open wire it was used between the insulators on the house and the protector. The insulators had tops which could be unscrewed to make the connection. It would be fixed to the house walls with lead lugs. I don't recollect staples being available for fixing this wire indoors. Protectors in customer's premises fell out of use when it was decided that protection would only be provided on lines with more than four spans of overhead and would be provided at the pole top. Things have now come full circle and modern line jacks incorporate protection.

Drop wire was exceedingly difficult to terminate on the terminal blocks used with telephones. They had clearly not been designed with drop wire in mind.

[AndiiT]

Originally Posted by davidw

Some models had a "knock out" in the base plate,under the pcb.

This knockout was originally intended for use with a Planset but was occasionally put to other purposes, such as running the wiring into a wall mounted instrument such as a 741.

Andrew