[Ian Bell[_2_]]

I am looking for a UK supplier of what we used to call GPO switches or
Key Switches or Lever Switches - the sort of two or three position
switch you used to see on vintage broadcast consoles or manual telephone
exchanges.

The only place I can fond that still makes them is Switchcraft in the US
but none of their UK distributors stocks them.

Cheers

Ian

[Peter Wieck]

On Feb 15, 6:24*pm, Ian Bell wrote:
I am looking for a UK supplier of what we used to call GPO switches or
Key Switches or Lever Switches - the sort of two or three position
switch you used to see on vintage broadcast consoles or manual telephone
exchanges.

The only place I can fond that still makes them is Switchcraft in the US
but none of their UK distributors stocks them.

Shipping is cheap from this end. What do you need and how many?

Peter Wieck
Melrose Park, PA

[Ian Bell[_2_]]

Peter Wieck wrote:
On Feb 15, 6:24 pm, Ian Bell wrote:
I am looking for a UK supplier of what we used to call GPO switches or
Key Switches or Lever Switches - the sort of two or three position
switch you used to see on vintage broadcast consoles or manual telephone
exchanges.

The only place I can fond that still makes them is Switchcraft in the US
but none of their UK distributors stocks them.

Shipping is cheap from this end. What do you need and how many?


Not decided yet. As soon as I do I'll take you up on that offer.

Cheers

Ian

Peter Wieck
Melrose Park, PA

[Ian Iveson]

Ian Bell wrote:

I am looking for a UK supplier of what we used to call GPO
switches or Key Switches or Lever Switches - the sort of
two or three position switch you used to see on vintage
broadcast consoles or manual telephone exchanges.

The only place I can fond that still makes them is
Switchcraft in the US but none of their UK distributors
stocks them.


I'm curious about what you mean, Ian. A picture would be
nice. I assume you don't mean a key switch as in ignition
key, for example, or a common lever-operated toggle switch.

How about:

http://accessories.musiciansfriend.c...&CJPID=2179950

Ian

[Ian Bell[_2_]]

Ian Iveson wrote:
Ian Bell wrote:

I am looking for a UK supplier of what we used to call GPO
switches or Key Switches or Lever Switches - the sort of
two or three position switch you used to see on vintage
broadcast consoles or manual telephone exchanges.

The only place I can fond that still makes them is
Switchcraft in the US but none of their UK distributors
stocks them.


I'm curious about what you mean, Ian. A picture would be
nice. I assume you don't mean a key switch as in ignition
key, for example, or a common lever-operated toggle switch.

How about:

http://accessories.musiciansfriend.c...&CJPID=2179950

Ian




Similar but not quite. Here is an example from the Switchcraft web site:

http://www.switchcraft.com/products/switch-302.html


Cheers

Ian

[mick]

On Mon, 16 Feb 2009 20:05:50 +0000, Ian Bell wrote:

snip

Similar but not quite. Here is an example from the Switchcraft web
site:

http://www.switchcraft.com/products/switch-302.html




Wow - not seen them for years! I thought they'd been replaced by this
pattern: http://www.leverkeyswitch.com/

--
Mick (Working in a M$-free zone!)
Web: http://www.nascom.info
Filtering everything posted from googlegroups to kill spam.

[Ian Bell[_2_]]

mick wrote:
On Mon, 16 Feb 2009 20:05:50 +0000, Ian Bell wrote:

snip
Similar but not quite. Here is an example from the Switchcraft web
site:

http://www.switchcraft.com/products/switch-302.html




Wow - not seen them for years! I thought they'd been replaced by this
pattern: http://www.leverkeyswitch.com/



Yes, those are the sort we used at Neve in the 70s and I am pretty sure
we called the GPO keys for some reason. It's funny a google search for
lever switches and key switches did not bring up that web site. Thanks
for that.

Cheers

ian

[Ian Iveson]

Ian Bell wrote:

Similar but not quite. Here is an example from the
Switchcraft web site:

http://www.switchcraft.com/products/switch-302.html

OK, thanks. Non-wiping contacts seems to be the objective.
They won't wear much, or become noisy, but I guess they need
occasional cleaning, and they look inherently costly.

What replaced them? Relays and FET switches, together with
logic chips for the complicated functions, I suppose.

Ian

[Ian Bell[_2_]]

Ian Iveson wrote:
Ian Bell wrote:

Similar but not quite. Here is an example from the
Switchcraft web site:

http://www.switchcraft.com/products/switch-302.html

OK, thanks. Non-wiping contacts seems to be the objective.

Along with one basic construction allows wide variation in number and
type of switches.

They won't wear much, or become noisy, but I guess they need
occasional cleaning, and they look inherently costly.


Indeed.

What replaced them? Relays and FET switches, together with
logic chips for the complicated functions, I suppose.


Possible. At Neve we used them mainly for talkback switches, but even
then the audio muting was done with relays.


Cheers

Ian
Ian

[Peter Wieck]

On Feb 17, 4:27*pm, Ian Bell wrote:

Yes, those are the sort we used at Neve in the 70s and I am pretty sure
we called the GPO keys for some reason. It's funny a google search for
lever switches and key switches did not bring up that web site. Thanks
for that.


I dunno. Writing only for myself as a hobbyist, I would stick with the
Switchcraft - the lifetime warranty from a company that has 'been
around a while' is quite attractive. I have no idea of the quantities
you need or the application or the longevity expected, so that may not
be your concern.

Peter Wieck
Melrose Park, PA

[Engineer[_2_]]

On Feb 17, 10:38*pm, "Ian Iveson"
wrote:
Ian Bell wrote:
Similar but not quite. Here is an example from the
Switchcraft web site:

http://www.switchcraft.com/products/switch-302.html

OK, thanks. Non-wiping contacts seems to be the objective.
They won't wear much, or become noisy, but I guess they need
occasional cleaning, and they look inherently costly.

What replaced them? Relays and FET switches, together with
logic chips for the complicated functions, I suppose.

Ian

Ian, did they not wipe a bit from the deflection of the parallel
arms? I remember them as GPO switches in my UK-youth. I seem to
recall the same action on a "GPO type 3000 relay" (name just from a
plaquing-over memory!)
Cheers
Roger
(near Toronto, Canada)

[Ian Bell[_2_]]

Engineer wrote:
On Feb 17, 10:38 pm, "Ian Iveson"
wrote:
Ian Bell wrote:
Similar but not quite. Here is an example from the
Switchcraft web site:
http://www.switchcraft.com/products/switch-302.html
OK, thanks. Non-wiping contacts seems to be the objective.
They won't wear much, or become noisy, but I guess they need
occasional cleaning, and they look inherently costly.

What replaced them? Relays and FET switches, together with
logic chips for the complicated functions, I suppose.

Ian

Ian, did they not wipe a bit from the deflection of the parallel
arms? I remember them as GPO switches in my UK-youth. I seem to
recall the same action on a "GPO type 3000 relay" (name just from a
plaquing-over memory!)
Cheers
Roger
(near Toronto, Canada)


Probably (I did not write the bit about non-wiping contacts). I have
recently got hold of some and interestingly the (outer) moving contacts
are normally bent (away) when not operated. When they are operated, the
lever moves them close to the vertical position where the touch the
fixed centre contact. The centre contact is moved only a very small
distance from the vertical so there is very little wiping action.

Cheers

ian

[Ian Iveson]

Ian, did they not wipe a bit from the deflection of the
parallel
arms? I remember them as GPO switches in my UK-youth. I
seem to
recall the same action on a "GPO type 3000 relay" (name just
from a
plaquing-over memory!)
Cheers
Roger
(near Toronto, Canada)

***Movement of contacts is small compared to distance from
pivot, so angle of movement is small, so sin(x) = x, to a
very close approximation, hence contacts move in a straight
line passing through their centres, more or less. Pivots are
also close together, so simultaneous deformation of both
contact strips will move the contacts in the same direction,
pretty much, and if the contact faces are domed, then what
miniscule motion remains can be partly or all taken up by
rolling rather than sliding.

***So if your objective was sliding contacts, that layout
would seem like a poor choice, on the face of it. They
certainly slide less than, er, sliding contacts.

***OTOH, if one contact strip bends considerably as the
other straightens significantly, then the contacts will move
in opposite directions, so they will wipe.

***How much sliding is required to keep contacts clean I
wonder? With relays, options for sliding or not are often
available. Something of a black art, probably. Maybe they
just make a wild guess.

Ian

[Dave]

Ian Bell wrote:
Engineer wrote:
On Feb 17, 10:38 pm, "Ian Iveson"
wrote:
Ian Bell wrote:
Similar but not quite. Here is an example from the
Switchcraft web site:
http://www.switchcraft.com/products/switch-302.html
OK, thanks. Non-wiping contacts seems to be the objective.
They won't wear much, or become noisy, but I guess they need
occasional cleaning, and they look inherently costly.

What replaced them? Relays and FET switches, together with
logic chips for the complicated functions, I suppose.

Ian

Ian, did they not wipe a bit from the deflection of the parallel
arms? I remember them as GPO switches in my UK-youth. I seem to
recall the same action on a "GPO type 3000 relay" (name just from a
plaquing-over memory!)
Cheers
Roger
(near Toronto, Canada)


Probably (I did not write the bit about non-wiping contacts). I have
recently got hold of some and interestingly the (outer) moving contacts
are normally bent (away) when not operated. When they are operated, the
lever moves them close to the vertical position where the touch the
fixed centre contact. The centre contact is moved only a very small
distance from the vertical so there is very little wiping action.

Cheers

ian
http://www.surplussales.com/Switches/SWLeaf-1.html

[Ian Bell[_2_]]

dave wrote:
Ian Bell wrote:
Engineer wrote:
On Feb 17, 10:38 pm, "Ian Iveson"
wrote:
Ian Bell wrote:
Similar but not quite. Here is an example from the
Switchcraft web site:
http://www.switchcraft.com/products/switch-302.html
OK, thanks. Non-wiping contacts seems to be the objective.
They won't wear much, or become noisy, but I guess they need
occasional cleaning, and they look inherently costly.

What replaced them? Relays and FET switches, together with
logic chips for the complicated functions, I suppose.

Ian

Ian, did they not wipe a bit from the deflection of the parallel
arms? I remember them as GPO switches in my UK-youth. I seem to
recall the same action on a "GPO type 3000 relay" (name just from a
plaquing-over memory!)
Cheers
Roger
(near Toronto, Canada)


Probably (I did not write the bit about non-wiping contacts). I have
recently got hold of some and interestingly the (outer) moving
contacts are normally bent (away) when not operated. When they are
operated, the lever moves them close to the vertical position where
the touch the fixed centre contact. The centre contact is moved only a
very small distance from the vertical so there is very little wiping
action.

Cheers

ian
http://www.surplussales.com/Switches/SWLeaf-1.html


Thanks, excellent link.

Cheers

Ian

[Dave]

Ian Bell wrote:

Cheers

ian
http://www.surplussales.com/Switches/SWLeaf-1.html


Thanks, excellent link.

Cheers

Ian

No prob.