| Letter |
Type |
Insulation |
Purpose |
| A |
Plaited, tinsel conductors. |
Textile |
Telephone instruments in dry situations (except
for instruments shown under D and G). |
| B |
Plaited, tinsel conductors. Waterproof.
|
Rubber |
Ditto in damp situations. |
| C |
As for B, but with stronger outer covering.
|
Rubber |
Linemen's and other portable telephones. |
| D |
As for A, but with better flexibility.
|
Textile |
Microtelephones and recs. |
| E |
Stranded, copper conductors.
|
Impregnated textile. |
Flex. intl. connections of instruments. |
| F |
Braided overall, copper conductors and strong
outer covering. |
Rubber |
Testing appliances and telegraph. instruments
etc. |
| FSI |
As for F except that 1 conductor is copper
screened. |
|
|
| G |
Braided overall, copper conductors. |
Impregnated textile. |
House and intercom. telephones, etc. |
| GS |
2-pairs. As for G except that 2-pairs are
copper screened. |
|
Loudspeaker instruments. |
| H |
Braided overall, copper conductors.
|
Rubber |
Combined bell-sets and telephones, etc. |
| J |
Stranded, tinsel conductors.
|
Textile |
Wiper Cords |
| K |
Cab tyre, tinsel conductors. |
Rubber |
Microtelephones and receivers in exposed
situations (street boxes ; Police, Fire, etc.). |
| KB |
Cab tyre, braided overall, tinsel conductors.
|
Rubber |
Alternative to K type for special cases (under
carpets, etc.) |
| L |
Cab tyre, copper conductors and high
insulation.
|
Rubber |
Mains supply connections of tele-printers, etc. |
| M |
Cab tyre, copper conductors. |
Rubber |
Telephone instruments, in exposed situations
(except for instruments shewn under K). |
| AA |
Plaited, tinsel conductors. |
P.V.C. |
Telephone instruments |