Technical Antique Horn Adjustment

Just tested this horn with my battery charger. The horn makes noise under both 6 and 12 volt connections. However the noise is more like a raspy sound. I see there are two adjustments on the top but before i dive in and screw it up ...can anyone tell me how to go about it? Suuggestions and direction info and knowledge appreciated
Regards

 

Its a Sparton horn, under the adjustment screw are points, after awhile the get dirty and stick together, they can be filed down.

 

two points of adjustment on top which is the adjustment screw?

 

Is it a 6 volt horn? It should probably be adjusted on 6 volts. Find out the current draw, ordinarily I think that's how they were adjusted. With an ammeter in series, sound the horn and adjust till the amperes reach nameplate current draw. It's in the manual somewhere. If it has a condenser (capacitor) that should probably be renewed. Ordinarily they probably never needed adjusting.

 

Adjust when it's blowing,but don't hold it on for more then a few sec. at a time. Adjust for the sound you like.

 

Absolutely no knowledge of these.
But if you’re ready to dive in.
Google is your friend.

https://www.google.com/search?clien...6j0i131j0i22i30j0i22i10i30j33i299.osNsJlIgUJ0

 

Hook it up to a battery, not a charger. Old/cheap chargers just supply rectified AC, which pulses at 120Hz (assuming a full wave rectifier and 60Hz AC). A horn will not give the correct sound when the current powering it is chopped up like that, it will mostly "play" the frequency of the supply.

 

Good catch. Use a battery for testing.

 

Maybe use 10 amp fuse between battery and horn - once you let the smoke out of them taint no good


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I know this is an old thread, but I have the exact same horn as the OP and can't find any specifics about it through Google. Mine is stamped Spartan C-8. Does anyone know what it would have been on originally?

Mine was one my Dad found somewhere and he had taken it apart to rebuild and potentially use on his 53' Ford F-100, before he passed away. It was very rusty inside from trapped water and I finally got it all cleaned, polished, painted and back together. We had to completely take it apart to get all the pieces clean of rust so I'm having to adjust it with no reference of where it was at, but the photo above is very helpful.