Hydrogen Thyratron Pulse Modulator Tube from China
Hydrogen thyratrons are specialized gas electron tubes designed for radar pulse modulators and high-voltage switching in scientific instruments. The low-pressure hydrogen gas enables fast switching, qualifying as a vapor electron tube under HTS 8540.89.0020.
Duty Rate — China → United States
41.2%
Rate breakdown
9903.88.0125%Except as provided in headings 9903.88.05, 9903.88.06, 9903.88.07, 9903.88.08, 9903.88.10, 9903.88.11, 9903.88.14, 9903.88.19, 9903.88.50, 9903.88.52, 9903.88.58, 9903.88.60, 9903.88.62, 9903.88.66, 9903.88.67, 9903.88.68, or 9903.88.69, articles the product of China, as provided for in U.S. note 20(a) to this subchapter and as provided for in the subheadings enumerated in U.S. note 20(b) [to this subchapter]
9903.05.3112.5%Section 301 (forced labor) — additional 12.5% ad valorem on products of China
Import Tips
• Include operating voltage/current ratings in import docs to distinguish from lower-power tubes
• Ensure supplier provides gas fill type certification to prevent reclassification
• Watch for antidumping duties if sourced from specific Asian manufacturers