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Vintage Telephony and Telecomms Vintage Telephones, Telephony and Telecomms Equipment |
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16th May 2011, 7:15 pm | #1 |
Octode
Join Date: Sep 2009
Location: Bath, Somerset, UK.
Posts: 1,033
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764 Push Button Phone - no pulse
I have acquired a 2/764. I left it plugged into a BT socket to charge the internal battery for an hour. It doesn't dial out (no pulse).
I've checked the ni-cad. It is putting out 1.8v. There is no mention of what voltage the beast runs on here: http://www.britishtelephones.com/t764.htm HELP! SEAN
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16th May 2011, 7:53 pm | #2 |
Retired Dormant Member
Join Date: Oct 2007
Location: Leicester, UK.
Posts: 809
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Re: 764 Push Button Phone - no pulse
How many cells? Should be a nominal 1.25V or thereabouts per cell. 1.8v doesn't sound right!
Brian |
17th May 2011, 7:26 am | #4 |
Octode
Join Date: Sep 2009
Location: Bath, Somerset, UK.
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Re: 764 Push Button Phone - no pulse
Thanks - possibly it isn't charging properly - the voltage going to the battery is very low indeed. From the looks of things it should charge directly from BT socket.
SEAN
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17th May 2011, 7:56 am | #5 |
Heptode
Join Date: Sep 2006
Location: Woodbridge, Suffolk, UK.
Posts: 643
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Re: 764 Push Button Phone - no pulse
What colour is the battery?
Battery secondary No 22 (RED) = 4.8v 150mA. Battery secondary No 23 (BLUE) = 7.2v 150mA. Both were used during the life of this phone. Connecting a battery of the appropriate voltage should prove your battery or another fault.
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Dave G1AGK. My perception is my reality! Last edited by davidw; 17th May 2011 at 7:59 am. Reason: extra data |
17th May 2011, 8:55 am | #6 |
Retired Dormant Member
Join Date: Oct 2007
Location: Leicester, UK.
Posts: 809
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Re: 764 Push Button Phone - no pulse
The cells could well have dendrites and therefore be pulling the charging voltage down have you measured the charging voltage with it out of circuit?
Brian |
17th May 2011, 9:02 am | #7 |
Octode
Join Date: Sep 2009
Location: Bath, Somerset, UK.
Posts: 1,033
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Re: 764 Push Button Phone - no pulse
I measured the voltage at the socket that charges the battery with the blue battery removed. It was measuring about 1 volt. I was shocked as the ni-cad had more voltage than that.
I could try stuffing 7.2 volts down the socket to see if the phone starts dialling out...... thanks again SEAN
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