Profile: Chambers Electronic Co., Inc. offers electronic test equipments for railroad signal communications. Our products are relay test sets, speaker phones, insulated joint testers, track circuit calibrators and track circuit testing shunts. Our model 11-A dynamic insulated joint testers are designed to find shorted insulation fast. It identifies insulation that is leaking AC current which degrades or compromises motion responsive and other types of electronic track circuits. Our SP 300 speaker phones are rain proof speaker phones housed in a gasket sealed, medium impact ABS case with all terminals and controls sealed.