4901-9105 Horn Question

I’m sure some of you may remember my problem with the Gamewell (Gamewell branded Federal Signal 450D with VALS) horn , well I awhile ago received some 4901-9805’s with the light plate and some horns are making that “dying Giraffe” sound that happens when it’s old. Can this be fixed by tightening the tab on the horn as I assume it’s just loosening over time and can be put back, or is this another problem? I don’t think the horns rust as I haven’t seen any deteriorating metal. Thanks for any help you can give me.

In those 450s there is an electrical contact that rapidly opens and closes when the horn is operated. Over time, it can get dirty from use or dust. Just run one of them without a backbox to find it, because it emits a small amount of light when it does. You can disassemble the horn or get something that removes carbon dust and stick it in between the two conductors. It may take awhile, but it does work. Make sure to tune the horn when you are done, to get the best performance.

Would the same apply to the Simplex horn? So your saying it’s just dust, as I do see some dust on the vibrating plate behind the horn grille. I’m afraid to disassemble the alarm as I have trashed the Gamewell version of the 450D and have given up trying to tune it. I have even lost some screws in the process. How would I safely go about doing this?

The 9805 horn does not have a mechanical contact, so dust would not affect the operation. Instead, a microchip is used to generate pulses to the electromagnet, and thus the sound from the device.

Unfortunately, the circuit board design does not work as well as the old-style contacts. Almost every 9805 out there sounds very rough and scratchy, but there is little that can be done about it since there is no physical way to adjust the switching mechanism - it’s all electronically controlled.

Do you mean the 9105? I took a second look at the horn and I did find a microchip on the circuit board that I never noticed. So what about those videos especially from brettman273, I’ll link the video, that shows the 4903-9219 which is the same horn as the 4901-9105 sounds like a dying giraffe in the beginning and sometimes he hits the horn and it slightly get’s better? Any reason for that or were the alarms made that way?

The horn’s model number should be 9805. These are from the same series as the 9219-style horns, as you mentioned. Perhaps the label on your device is obscured, because Simplex used the 9105 model number on remote strobes.

I suppose bumping the alarm could adjust the vibrations of the diaphragm in order to slightly improve the sound quality of the horn, but there is no way to fix the root issue of the poor sound quality.

You’re right, I took a second look it is the 9805. Don’t know how I missed that since it’s clearly labeled. So the roughness of some horns is normal and not a result of decaying materials or anything like that. I want these horns to live for as long as possible since they’re not in production anymore.

You are correct. There’s a good chance that one of these horns brand new from the box would sound nearly as rough as one that has been in service for years.

In theory, these horns should last longer than those with mechanical switching mechanisms, since there are fewer moving parts. On the flip side of the argument, there is the possibility that the sensitive electronic components may be more prone to failure than the more robust mechanical mechanisms. I don’t think there is much evidence to support either side, so keeping the horn well maintained and clean will offer the best opportunity to ensure it continues to operate as intended.

Awesome, thanks for the information

The reason that some of the horns sound like they’re on the way out is because dirt and grime gets into the vibrating mechanism and clogs it up and makes it stick. Smacking the device can sometimes dislodge the particles and allow the device to vibrate freely

Speaking of that, our (Probably) 9219 has alot of dirt in its mechanism from being outside, and i was wondering if there was a way to disassemble and clean it.

You CAN disassemble these devices to clean them however the question of SHOULD you depends on the situation.
If the device is to be used for actual life safety, then no. For those intents and purposes it is not user serviceable, if it’s failing, you don’t repair it you replace it.
If it’s a device in your collection then yes! There is a lot to be learned from disassembling a device to see how it works! Although note that this will void the CRAP out of any warranty that might still apply to the device. Also, it takes a delicate touch. One slip of the screwdriver or just a quarter-turn too tight can and will wreak havoc on the device in question. Sometimes just the act of disassembling and reassembling a device can make it work better. The electrical connections that you take out and put back in have the tarnish scraped off of them, you can re-tighten any pitch/volume screws that may have wriggled loose over the years, etc. A lot of those buzzing Simplex horns have a little transformer of some sort in them that vibrates the speaker cone and makes the earsplitting buzz. When dirt, grease, and/or grime builds up against the cone or the vibrator it can impede normal vibrations and cause the sputtering sound or outright failure. I’ve heard of someone selling rebuild kits for a specific set vibrating horns at one point (I do not remember if it was Simplex or Faraday or whoever) so technicians could replace coils or speaker cones devices but I cannot remember specifically.