I don't know about fire alarm strobes, but I have some strobe light drivers and I know how they work. Usually they consist of a small step up transformer, the primary of which is driven by the discharge of a small capacitor. This sends an HV pulse to the antenna outside the tube which discharges a larger capacitor through the tube. I would say the most likely thing to go wrong is in the triggering circuitry. This is sometimes done with a neon indicator, but could be more complicated with fire alarms if they are supposed to strobe synchronously. Usually they aren't that complicated, just start checking the different components until you find a bad one. Do you have a picture of the board?

In addition to collecting lighting related things, I also collect fire alarms (technically lighting related as well. Among my collection I have many devices that contain strobes. Most of them work, but I do have two that don't work that I would like to get working. Specifically, a Simplex 2903-9150 120V strobe plate, and a Space Age Electronics A32 white strobe plate. Does anyone on this site have experience in strobe circuits or repairing them?

@LightBulbFun
Excellent point, I did not consider that. Of course an RMS ammeter has the final say, but if you can find chokes that are just for 18-20W tubes it would probably be better than those 14-20w ones.

@funkybulb
That is a very good idea, common 18-20W chokes provide 240 ohms at 118V, while (according to my calculations) the tube needs ~125 ohms. Two 18-20W chokes in series gives 120 ohms which is close enough. Plus preheat is a lot cooler than RS in my opinion.

a 20W *Reference ballast* is 240 ohms, but many production ballasts are not, especially not your common 14W-20W choke some of which dont even drive a F15T8 at full power, just keep that in mind when trying to work things out like this

@funkybulb
That is a very good idea, common 18-20W chokes provide 240 ohms at 118V, while (according to my calculations) the tube needs ~125 ohms. Two 18-20W chokes in series gives 120 ohms which is close enough. Plus preheat is a lot cooler than RS in my opinion.

 If u  have two  15  to  20 watt  preheat  chokes  and  combine the  two  in  perallel.  It will run a  F30T12
High output quite easly just unsing  two  preheat chokes
 And FS 2 starter.   

I like how he blows on the electrical code! 🤣, bet that infuriates the time served old boy electricians 😫

I was looking at Lamptech and some other resources at gas fill types for fluorescent tubes. All I can consistently find is that normal-output T12 tubes have approximately 3 torr of argon inside. Well that is all fine and dandy, but not all tubes are T12 NO. Are the gas fills for HO and VHO the same as NO? How about krypton tubes, are they pure krypton or a mix (and at what pressures)? I hear there is xenon and neon in some other tubes, what pressures are those at?

Does anybody have a chart or resource (or just know off the top of their head) what fills are in different diameter and different output level fluorescent tubes? I would like to add this to my public lamp spec sheet.

@Ash
Thanks so much! I am certainly not in a rush.

I have a few Eltam SR40 on hand and could make some measurements if you would like, though you will have to wait until i have a window of free time