Arrangements of transmitters, receivers, or complete sets to prevent eavesdropping, to attenuate local noise or to prevent undesired transmission; Mouthpieces or receivers specially adapted therefor (circuit arrangements for preventing eavesdropping H04M1/68; telephone cabinets E04H1/14)

Introduced: September 1968

Title

Titles differ between systems:

IPC: Arrangements of transmitters, receivers, or complete sets to prevent eavesdropping, to attenuate local noise or to prevent undesired transmission; Mouthpieces or receivers specially adapted therefor

CPC: Arrangements of transmitters, receivers, or complete sets to prevent eavesdropping, to attenuate local noise or to prevent undesired transmission; Mouthpieces or receivers specially adapted therefor (circuit arrangements for preventing eavesdropping H04M1/68; telephone cabinets E04H1/14)

Full Title

Full titles differ between systems:

IPC:

Substation equipment, e.g. for use by subscribers > Constructional features of telephone sets > Arrangements of transmitters, receivers, or complete sets to prevent eavesdropping, to attenuate local noise or to prevent undesired transmission; Mouthpieces or receivers specially adapted therefor

CPC:

Substation equipment, e.g. for use by subscribers (subscriber services or facilities provided at exchanges H04M3/00; prepayment telephone coin boxes H04M17/00; current supply arrangements H04M19/08) > Constructional features of telephone sets > Arrangements of transmitters, receivers, or complete sets to prevent eavesdropping, to attenuate local noise or to prevent undesired transmission; Mouthpieces or receivers specially adapted therefor (circuit arrangements for preventing eavesdropping H04M1/68; telephone cabinets E04H1/14)

No child classifications to compare. This is a leaf node in both IPC and CPC.