Lightboxes
Panier
alb2589708

Telephone model from the 1970s.

Telephone model from 1975. The first telephones for tone signalling of numbers were put to use in 1975 in areas with computerised telephone exchanges. The principle behind tone signalling is that each digit has a standardised frequency or tone which is sent to the exchange. This model is a modified standard 1967 telephone where the numbers dial has been replaced by a push-button keyset.
Partager
pinterestPinterest
twitterTwitter
facebookFacebook
emailEmail

Ajouter à une autre Lightbox

Ajouter à une autre Lightbox
add to lightbox print share
Avez-vous déjà un compte? S'identifier
Vous n'avez pas de compte ? S'inscrire
Acheter cette image
Chargement...
Titre:
Telephone model from the 1970s.
Légende: Voir la traduction automatique
Telephone model from 1975. The first telephones for tone signalling of numbers were put to use in 1975 in areas with computerised telephone exchanges. The principle behind tone signalling is that each digit has a standardised frequency or tone which is sent to the exchange. This model is a modified standard 1967 telephone where the numbers dial has been replaced by a push-button keyset.
Crédit:
Album / Universal Images Group / Universal History Archive/UIG
Autorisations:
Modèle: Non - Propriété: Non
Questions sur les droits?
Taille de l'image:
5100 x 3930 px | 57.3 MB
Taille d'impression:
43.2 x 33.3 cm | 17.0 x 13.1 in (300 dpi)
Mots clés: