where to get cable for my addressable fire alarm ?
Personally, I use Plenum FPLP 14/2 fire alarm cable for my systems. This basically means there are two solid conductors running through one single jacket. I was able to get this on eBay for a pretty good deal, so basically all of your alarm needs can be met if you search around on that site. If you cannot find or aren’t willing to pay for that, you could probably get away with using some standard 14 AWG wire, such as that commonly used for AC wiring, since the scale of a demonstration system is so small. You can pick this type of wire up at almost any home improvement store. Just remember that solid and stranded wire both have their pros and cons: stranded is easy to pull and can fit more cleanly into electrical boxes. On the other hand, solid wire is easier to correctly make terminal connections with, but it is very stiff and a pain in the rear to fit into electrical boxes when devices are installed.
Check the wiring specs for whatever addressable system you have, then purchase cable accordingly. Can it be single conductor? Or does it need to be twisted pair? Shielded? Minimum/maximum wire gauges to fit under the terminals? (Usually anywhere from 14awg to 18awg will work fine)
+1 on what Chris said - but as far as locating some cable, if you don’t need a 500’ box, for a small project you may want to just stop by a local small alarm company and ask if they have some scrap pieces laying around they would be willing to sell you for cash. It’s not uncommon to have some <100’ lengths hanging around the shop when you need a small piece for a job. The larger companies don’t really sell directly to the public.
On a side note, a couple years ago I was in a Home Depot somewhere in Northern Virginia. They actually had fire wire by the foot in their electrical department. That’s the only Home Depot I ever saw that at, the local stores here didn’t supply it. So maybe there was some specific demand for it in that area?