Another electrical question - horn rewiring

[Marshall V. Daut]

If you have been following the never-ending saga I started two weeks ago about repairing a light switch rod's functionality, you will also recall that the ahooga horn was on its last legs when I tested the repaired rod (which ultimately broke off). We bit the bullet and ordered a new light switch rod. Problem #1 solved.
Problem #2 reared its ugly head in the form of a burned-out ahooga horn. Upon testing the rod, the near-death horn with its crispy burned wiring finally died. My past contact people for rewiring horns are either dead or don't respond anymore. I have watched an on-line video on how to rewire the horn and although I am still a dunce when it comes to electrical matters, I think I can handle this job. I'll post a link to the video I refer to here at the end of this question. In the video, the man says to use #20 insulated copper wire and wrap each pole 40 times. Les Andrews in his red book says 48 turns each for the same recommended wire. For those of you who have done this, which number of windings will work better: 40 or 48? Or does it matter in that range? I could wind the poles 48 times and if not satisfied with the sound, unwrap eight turns and try again. But that entails a lot of soldering and unsoldering. I'd rather get it right the first time.
The reason I am not relying 100% on the video's recommendation of 40 turns is because at the end of the video when the assembled horn was tested, it sounded sick and didn't seem to want to reach the "ahooga!" sound we are all after. It could be the small test battery he used didn't provide enough juice. We all know that the ahooga horn sounds better when the engine is running and generator is charging. Still, I want to do this unfamiliar job right only once. So, what is recommended by the electron-minded readers here for number of turns: 40 or 48? Maybe a short explanation of the difference would be helpful, too.
Here's the promised video link: https://www.youtube.com/watch?v=80HheWrv2_s. As a video producer who made exclusively training videos for a living, I would have done several things differently. But for an amateur garage type of video, it's helpful enough for my purposes. I think you will find it entertaining.
Marshall

[rotorwrench]

Some of these procedures are for 12-volt conversions. The wire guage and number of turns is different. I'd just count the number during removal. Magnet wire is available. Rebuilding the armature is more complicated.

[Marshall V. Daut]

Yes, the 12-volt conversion was touched upon in that video: #24 wire wrapped 100 times around each pole. But I am keeping this horn in its original 6-volt configuration, so it'll be either 40 or 48 turns.
Marshall

[Bigsnapper43]

We can supply a restored unit. Give me a call. 740 658 3495

[Marshall V. Daut]

Thanks for the offer, BIGSNAPPER43, and we'll keep it in mind. But besides my friend's horn that needs to be rewired, I have three or four other D.O.A. horns that came to me with cars I bought and I would like to rewire them, too. I am looking at my friend's rewiring as a "learner project", making mistakes with his horn that I can avoid when I do mine later.
However, since you restore horns, maybe YOU could tell me the recommended number of turns for a 6-volt horn? How many turns do you use in your restorations? Can you tell the difference between 40 and 48 turns in the horn's operation?
Marshall

[nkaminar]

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The more windings, the higher voltage it will take to get the same amperage through the horn. So with more windings the horn will run slower and have a more mellow tone. I would recommend going with the 48 windings for this reason. However, different manufacturers used different amount of turns, so count the turns when you take the old windings out.

[Marshall V. Daut]

Good info! Thanks, nkaminar. The wires originally used were probably not coated with enamel insulation, more likely with cloth. I wonder if the coating differences between cloth and enamel would make a difference in the number of windings, i.e. now recommended 48 instead of 40? I will definitely count the number of windings as I remove them. If I had access to the exact wire and covering used by the horn companies, I would replicate the exact number of turns. But with the modern enamel coated wire, maybe that changes things?
M.

[the cooch]

I would think the length of the wire would be the more important factor. As stated the different types of insulation could change the number of windings necessary as could the diameter of the post, right? Maybe take apart a few and measure for an average length of wire and measure the diameter of the poles on a few examples? Be careful to avoid bends or kinks in the new wire as it goes on for sure, maybe build a fixture to hold light tension? Good luck! I am about to try to restore an “ahoooga” horn and will be winding some coils for some old doorbells soon too, so looking forward to following the progress. -Chris, in Boulder

[nkaminar]

The length of the wire will change the resistance and thus the current. But the magnetic force is determined by something called the ampere-turns. That is the amps times the turns. So if current is important then go with the length of the wires. To keep the turns the same with enamel insulation, layers of turns could be separated with wraps of the cloth electrical tape, what we used to call friction tape.

[katy]

https://www.amazon.com/BNTECHGO-AWG-...zcF9hdGY&psc=1

[Marshall V. Daut]

Yesterday I had found this one that I was going to order tomorrow: https://www.amazon.com/BNTECHGO-AWG-...732529424&th=1

Any difference?
Marshall

[katy]

Only difference I can find is the color.

Here is some info I saved from an earlier thread:

Information for the field coils:

6 Volt

(1) The 2 field coils are wound in opposite directions.
(2) Original field coil wire is 20 gauge.
(3) a. 45 turns using coated wire.
b. 6 to 7 turns per layer, not perfect is OK
(4) After completing, spray with varnish or epoxy insulating enamel.

12 Volt

(1) The 2 field coils are wound in opposite directions.
(2) Use 24 gauge coated wire.
(3) a. 100 turns
b. 6-7 turns per layer, not perfect is OK
(4) After completing, spray with varnish or epoxy insulating enamel.

HTH,

[Marshall V. Daut]

More good information, thanks, although I don't see why after winding the insulated wire has been completed, you should spray a varnish or epoxy over the wire. Isn't that why the wire is insulated inside enamel in the first place?
M.

[Marshall V. Daut]

More good information, thanks, although I don't see why after winding the insulated wire has been completed, you should spray a varnish or epoxy over the wire. 'Couldn't hurt anything, but isn't that why the wire is insulated inside enamel in the first place?
M.

[Marshall V. Daut]

Double post = double the fun.
M.

[nkaminar]

I suspect that spraying with enamel, or dipping in enamel, is to fix the wire from moving around and thus to protect it from fraying and rubbing off the insulation.

[Klattu1929]

Be carefull the ratchet nut may be left hand threads, mine was, I found out the hard way.

[Marshall V. Daut]

That makes TWO of us!
M.

[kbinde2]

You have several horns to rebuild, all the same manufacture.? I think some brands had left thread pattern, others used right hand.. just a caution as you work with different brands along you journey.. kb

[Herb Concord Ca]

Stewart Warner horns are left hand threads. The others are right hand.
Make sure that you wind the second coil in the opposite direction, if you don't the horn will not run.