| Business | Phone |
| Communications Engineering Co 6230 N Brady St, Davenport 52806 | (563) 386-0377 |
| Illowa Security Products 1354 W 4th St, Davenport 52802 | (563) 322-0981 |
| Midwest Radio Svc 5915 N Brady St, Davenport 52806 | (563) 386-7344 |
| Racom 317 W 13th St, Davenport 52803 | (563) 323-2812 |
| River City Communications 5327 Carey Ave, Davenport 52807 | (563) 386-1100 |
| Tomar Electronics 5803 Forest Rd, Davenport 52807 | (563) 332-2237 |