706L telephone - extra gravity switch - UK Vintage Radio Repair and Restoration Discussion Forum

Sparks · 10th Jun 2020, 2:40 pm

This 1965 model arrived today. As well as having a recall button, there is another gravity switch on the opposite side to the usual one. However, it only has two wires - grey and blue - and these are wired in parallel with the grey and blue wires off the recall button. What might this switch be for please ? This switch is 'on' when the handset is on-hook. Thankyou.

JohnBHanson · 10th Jun 2020, 4:37 pm

Possible for use with a pmbx 2 which use 4 wires

Sparks · 10th Jun 2020, 5:33 pm

Thanks John. I'll probably end up converting the phone for regular use, in which case I'll leave the switch in but park the wires on spare terminals.

Dave Moll · 10th Jun 2020, 6:42 pm

I recently wired up a Plan 105 (external) which required an additional gravity switch on each extension. In my case I used 746s, but maybe such a 706 would serve a similar function, except that I recall it specifying change-over contacts on the extra gravity switch.

AndiiT · 10th Jun 2020, 6:47 pm

Hi, almost certainly a C wire signalling switch for use with a PMBX 2/X series PBX. See Page 2 fig.4 here

Andrew

Sparks · 10th Jun 2020, 7:40 pm

It's definitely just a simple on/off switch with just the two wires.

I'll leave the recall button as it is. Will I really need to disconnect the extra switch or can I leave it as is ? Either way I shall leave it fitted inside. It's just going to be a plain phone, no PMBXs etc.

Sparks · 10th Jun 2020, 11:08 pm

PS. This telephone is a product of Phoenix Telephone and Electrical works - it has PXA printed on the base.

Pellseinydd · 11th Jun 2020, 10:03 am

Quote:

Originally Posted by Sparks

It's definitely just a simple on/off switch with just the two wires.

I'll leave the recall button as it is. Will I really need to disconnect the extra switch or can I leave it as is ? Either way I shall leave it fitted inside. It's just going to be a plain phone, no PMBXs etc.

Can leave as is - see fig 4 on N806 or converted as Tele 8746 similar connectionsN8846 Fig 3

Sparks · 11th Jun 2020, 11:08 am

Thankyou, Pellseinydd. I'll leave it alone. The phone works fine with all the additional switches anyway so if it ain't broke...

It will be nice to have a black functioning 706 in my arsenal. The Ericsson magneto 706 I got back in April looks smart but sadly isn't much use to me.

10th Jun 2020, 2:40 pm	#1
Sparks Heptode Join Date: Oct 2006 Location: Leeds, West Yorkshire, UK. Posts: 596	706L telephone - extra gravity switch This 1965 model arrived today. As well as having a recall button, there is another gravity switch on the opposite side to the usual one. However, it only has two wires - grey and blue - and these are wired in parallel with the grey and blue wires off the recall button. What might this switch be for please ? This switch is 'on' when the handset is on-hook. Thankyou. Attached Thumbnails

10th Jun 2020, 4:37 pm	#2
JohnBHanson Heptode Join Date: Aug 2009 Location: Worthing, Sussex, UK. Posts: 661	Re: 706L telephone - extra gravity switch Possible for use with a pmbx 2 which use 4 wires

10th Jun 2020, 5:33 pm	#3
Sparks Heptode Join Date: Oct 2006 Location: Leeds, West Yorkshire, UK. Posts: 596	Re: 706L telephone - extra gravity switch Thanks John. I'll probably end up converting the phone for regular use, in which case I'll leave the switch in but park the wires on spare terminals.

10th Jun 2020, 6:42 pm	#4
Dave Moll Dekatron Join Date: Feb 2005 Location: West Cumbria (CA13), UK Posts: 6,127	Re: 706L telephone - extra gravity switch I recently wired up a Plan 105 (external) which required an additional gravity switch on each extension. In my case I used 746s, but maybe such a 706 would serve a similar function, except that I recall it specifying change-over contacts on the extra gravity switch. __________________ Mending is better than Ending (cf Brave New World by Aldous Huxley)

10th Jun 2020, 6:47 pm	#5
AndiiT Octode Join Date: Aug 2005 Location: Saltburn-East, Cleveland, UK. Posts: 1,786	Re: 706L telephone - extra gravity switch Hi, almost certainly a C wire signalling switch for use with a PMBX 2/X series PBX. See Page 2 fig.4 here Andrew

10th Jun 2020, 7:40 pm	#6
Sparks Heptode Join Date: Oct 2006 Location: Leeds, West Yorkshire, UK. Posts: 596	Re: 706L telephone - extra gravity switch It's definitely just a simple on/off switch with just the two wires. I'll leave the recall button as it is. Will I really need to disconnect the extra switch or can I leave it as is ? Either way I shall leave it fitted inside. It's just going to be a plain phone, no PMBXs etc.

10th Jun 2020, 11:08 pm	#7
Sparks Heptode Join Date: Oct 2006 Location: Leeds, West Yorkshire, UK. Posts: 596	Re: 706L telephone - extra gravity switch PS. This telephone is a product of Phoenix Telephone and Electrical works - it has PXA printed on the base.

11th Jun 2020, 11:08 am	#9
Sparks Heptode Join Date: Oct 2006 Location: Leeds, West Yorkshire, UK. Posts: 596	Re: 706L telephone - extra gravity switch Thankyou, Pellseinydd. I'll leave it alone. The phone works fine with all the additional switches anyway so if it ain't broke... It will be nice to have a black functioning 706 in my arsenal. The Ericsson magneto 706 I got back in April looks smart but sadly isn't much use to me.