Wednesday, 16 November 2011


As alluded to earlier in this blog a secondary interest sprung up in the form of buying and restoring vintage car horns. Since the first Desmo one I've learned something of the history of various marques. Interest has moved towards the motor driven types where a spinning serrated rotor acts on a hardened steel stud riveted to the centre of a spring steel diaphragm. The resulting sound is best described onamatopoeiacally as awoogah and typified by that heard on many vintage cars. Early versions were manually operated directly, usually with a push button driving a flywheel, but later an electric motor was used so they could be operated remotely. Both sides of the Atlantic the Klaxon brand name became synonymous with the generic type.

Having acquired a Klaxon Klaxonet, I was impressed with the quality of construction as well as the sound. When I learnt of the existence of the big daddy A1 model, also known as the model 20 in the USA, it became a must have. Its monster size and weight, 8 inches across the trumpet and nearly 4Kg, fitted in well with the OTT image I planned for my boat.

These horns are very rare particularly the long trumpet versions, but do appear very occasionally on eBay, although usually with unrealistic starting prices. I did eventually manage to acquire one privately though.

This particular horn is a long trumpet French version from Klaxon's sister company in Paris, probably built in the 1920's. Strangely it doesn't have a model name, just Klaxon being displayed on the plaque. Many of the British built A1 models had a mounting bracket supporting the bottom of the motor and attached to the lower part of the trumpet flange. This one has the bracket incorporated in the trumpet flange which is reversible and better suits my needs.

Solid brass construction apart from the brass and copper plated underslung motor suggests yet still more polishing experience. Although the plating on the cast iron motor housing is worn, I have just polished and lacquered that part for the moment. The sound is vicious, almost frightening in intensity and not dissimilar to a very angry duck, which sits well with its future location on the water. Just need to find a place to mount it now.

Although the recording (on my phone) doesn't really do it justice, you can hear it for yourself

Needless to say interest in the Desmo one has wained and its already been sold on eBay to help finance this purchase.


  1. I have this same horn and request assistance on how to wire the 4 terminals dc motor (2 are brushes to armature and 2 are to field coils). Respond to:

    1. Hi, it’s the two field wires you need to connect a DC supply to. The brush connections should ideally have plastic insulating caps over them. Polarity is not relevant as it’s a series wound motor so will only turn in one direction. Having said that an insulating washer on one of the field connections is sometimes replaced by a copper one to provide casing connection and so allow fitting to a vehicle with single positive wire and return to battery through casing. The working voltage (6 or 12 volts) should be stamped on the top bearing housing although maybe elsewhere.

      Don’t be tempted to test a 6 volt horn on 12 volt battery – it will draw four times normal current and quickly burn out one of the armature windings.

      Regards - Richard

    2. Hi I have a klaxon and don't know any thing about. Can I send you some pictures of it