Wheelock 7002T-24 Issue: Help!

So I have had a Honeywell SC807A1029 (Wheelock 7002T-24) for a while now, and it has worked perfectly fine…at least until this happened.

I powered the alarm up using my 24VDC power supply, and the horn sounded super raspy and the strobe flashes a lot slower than when I first got it. For more info, check my YouTube video titled ‘System Test 6: 7002T and RSS’. You can see in that video it sounds perfectly normal, no issues. Until at the end when it begins to sound raspy. I thought the source of the issue might have been the batteries dying then, but today I powered it up and it sounded really weird. I unconnected power and tested it with batteries to no avail. The weird thing is it should have sounded fine, but it sounded even worse. I thought those batteries might be dead, so I tried another 3 out. Same result.

This particular 7002T was manufactured in the 32nd week of 1990 and has the black coil holder thingy on the back, not the red painted one.



I really hope this thing isn’t broken somehow; it just seems odd that it sounded fine a couple of months ago, and now it is having some kind of problem.

It is important to know that I have in no way, shape, or form tested the alarm since I featured it in that System Test video. It’s just been sitting in a box with all my other alarms.

Because these things are rather rare nowadays, I don’t think I’d be able to find another on eBay within any sort of reasonable price. I’m super mad now because it worked fine a couple months ago and now it seems unfixable.

I figured I’d consult the board before trying to troubleshoot myself, because I’m sure I’m not the first unlucky person to experience the problem. The alarm itself is in amazing shape and sounded real healthy when I first got it in July, and I haven’t even set it off much since then.



I’d appreciate any help. Thanks.

Are you running it on filtered DC, or full wave rectified? Usually 7002Ts, and other mechanical horns will sound raspy if powered with full wave rectified DC.

Try to tighten the screws


All batteries are “filtered” DC. No battery will ever output FWR.

If you do so, be sure to make only slight adjustments the volume screw located near the switching contacts. Don’t mess with two screws to the left of the electromagnet, as these are likely set to a specific torque at the factory and adjusting them can throw off the mechanism of the horn.

Do you have a photo of where the screw is? I don’t really want to mess with anything until I know where it’s at.

Here’s the screw. I guess technically you will actually being adjusting the nut, not the screw itself. Be sure you make only very slight changes to this adjustment screw. Start off by turning it in 1/16-ish increments and check your progress as you go. I would avoid making more than a 1/4 turn adjustment in total.



As a note, once you adjust this screw it will be very difficult to match the original pitch of the horn.




Well if he can get it in key, for reference the 7002T is in a key of G#.


Actually, from what I’ve seen in many people’s videos of the 7002T, the pitch is actually a slightly sharp A#/Bb, much like the EST Integrity.

Maybe the ones I’ve seen people never bother to tune. :stuck_out_tongue:

I tightened it and I sounds worse, so I loosened it and it still sounds a tad bit scratchy…