Telephone fault - advice welcomed! - UK Vintage Radio Repair and Restoration Discussion Forum

LukeG83 · 28th Aug 2010, 2:24 pm

Hi I have a wall mounted 741 rotary dial phone. Been in house years and was converted by BT to a modern plug - and continued to work well.

Anyhow, when calling or answering the line is now very poor - crackly low volume etc.
However sometimes if you dial, or if you hold your finger slightly on the reciever without cutting off the call the line clears??

Any ideas what the problem may be (in laymans terms!) would be most appreciated.

I am still on a BT line and plugging another more modern phone into the box gives a clear line to the exchange.

Thanks Luke

russell_w_b · 28th Aug 2010, 4:27 pm

Do you mean holding your finger slightly on the cradle-switch, where you replace the handset, or the receiver (the thing in the handset that you place next to your ear)?

If you mean the cradle-switch it sounds like you have dirty contacts in there. I think a 741 has a sealed micro-switch in it. There's a cct-diagram here, and you can disconnect the switch terminals as appropriate and buzz them out, although it might be just as easy to fit a new micro-switch from a 'scrapper'.

LukeG83 · 28th Aug 2010, 5:07 pm

Hi - sorry for the confusion - it is the cradle switch.

Can new switches be purchased? Anyone got a spare I could buy??Thanks

Dave Moll · 28th Aug 2010, 5:23 pm

Your best bet is probably eBay. Assuming that this uses the same switch as the standard 746, they crop up quite frequently.

28th Aug 2010, 2:24 pm	#1
LukeG83 Hexode Join Date: Jul 2008 Location: Garstang, Lancashire, UK. Posts: 283	Telephone fault - advice welcomed! Hi I have a wall mounted 741 rotary dial phone. Been in house years and was converted by BT to a modern plug - and continued to work well. Anyhow, when calling or answering the line is now very poor - crackly low volume etc. However sometimes if you dial, or if you hold your finger slightly on the reciever without cutting off the call the line clears?? Any ideas what the problem may be (in laymans terms!) would be most appreciated. I am still on a BT line and plugging another more modern phone into the box gives a clear line to the exchange. Thanks Luke

28th Aug 2010, 4:27 pm	#2
russell_w_b Dekatron Join Date: Jul 2007 Location: Penrith, Cumbria, UK. Posts: 3,687	Re: Telephone fault - advice welcomed! Do you mean holding your finger slightly on the cradle-switch, where you replace the handset, or the receiver (the thing in the handset that you place next to your ear)? If you mean the cradle-switch it sounds like you have dirty contacts in there. I think a 741 has a sealed micro-switch in it. There's a cct-diagram here, and you can disconnect the switch terminals as appropriate and buzz them out, although it might be just as easy to fit a new micro-switch from a 'scrapper'. __________________ Regds, Russell W. B. G4YLI.

28th Aug 2010, 5:07 pm	#3
LukeG83 Hexode Join Date: Jul 2008 Location: Garstang, Lancashire, UK. Posts: 283	Re: Telephone fault - advice welcomed! Hi - sorry for the confusion - it is the cradle switch. Can new switches be purchased? Anyone got a spare I could buy??Thanks

28th Aug 2010, 5:23 pm	#4
Dave Moll Dekatron Join Date: Feb 2005 Location: West Cumbria (CA13), UK Posts: 6,127	Re: Telephone fault - advice welcomed! Your best bet is probably eBay. Assuming that this uses the same switch as the standard 746, they crop up quite frequently. __________________ Mending is better than Ending (cf Brave New World by Aldous Huxley)