Fine original production glass shoulder type pentodes manufactured in the United States by International. These great 6 pin pentagrid converter tubes with top cap were designed for service in battery radios as combined oscillators and mixers. They come with silver plates, smoked glass, and are printed in white INTERNATIONAL SERVICEMASTER U.S.A. Boxes are standard International blue printed 1C6.
Data sheet
Fine original production glass shoulder type pentodes manufactured in the United States by International. These great 6 pin pentagrid converter tubes with top cap were designed for service in battery radios as combined oscillators and mixers. They come with silver plates, smoked glass, and are printed in white INTERNATIONAL SERVICEMASTER U.S.A. Boxes are standard International blue printed 1C6.