It’s in relatively good condition, but needed a adjustment on the mechanism to give a clear ring; initially you could hear the solenoid firing, but no ring.
The adjustment resolved that.
I noticed a small diode connected to one side of the plug assembly, I’ve no idea what that was for.
At one time, I had a 4 inch Thomas bell that was relabelled “Montgomery Mfg” but the mechanism assembly was different.
I’m still searching for the installation sheet that tells how they were installed, but for now THIS ONE and maybe a 6" one later is pretty good.
You know, I’ve got basically the exact same bell, only mine says “ALARM-BELL” in place of “AUDIBELL” (such a variant seems rare as I can’t seem to find any photos of one online), & it doesn’t work properly either! Got any idea why? (the hammer moves forward toward the gong when power is applied, but that’s it: it won’t move back & forth repeatedly as it should)
It sounds like the solenoid might need repositioning; try moving it down and test ring it.
It’s been my experience that the closer the striker mechanism is to the gong, the louder the ring should be. But be careful not to have the striker touching the gong when not active, or it might not ring.
Sometimes if it’s close to being in the range to strike the gong, you will get a “chattering” intermittent ring.
Solenoid/striker designs are “quirky” sometimes; dual coil mechanisms with a striker can be too.
Those are usually an alternative to the single coil solenoid types.
Try what I suggested, and let me know.
You might also give a “blast” of spray lubricant a try but use it only on the striker where it enters the solenoid coil.
Some things I should mention: this bell is a model “T-154” & runs on 12VDC, unlike yours which takes 120VAC. I also moved the hammer down manually & it properly disconnects the contacts when all the way down, so I’m honestly not sure what the problem or problems with it could be.
Nice! I have the 6" Version (KB-506) that I got NIB with a Thomas Industries backbox (KB-8016) for it (the bell is mounted on that in the photo, and the original mounting plate is next to it).
(I know this last one is blurry but I didn’t realize until after I had taken it (it seems like it’s always very hard (if not outright impossible) to get a clear shot with the camera I use unless you hold it absolutely perfectly still). It doesn’t show much more than the first photo I sent anyway)
I for one prefer 24VDC notification appliances as a whole for several reasons, including that 24VDC is (arguably) much less dangerous to work with than 120VAC, that it’s the standard voltage output by most modern FACPs (thus making them easy to power), & that they often sound nicer compared to AC-powered NAs, which usually buzz (if they’re horns at least).
No, but I could: didn’t even notice they were arranged that way.