2D21
2D21 has no equivalent designation confirmed by the archive. Completed sales put the typical price at $6.56 per tube.
What 2D21 Sells For
| Measure | Per tube |
|---|---|
| Median | $6.56 |
| Typical range (25th–75th) | $4.55 – $15.42 |
| Most sales (10th–90th) | $3.05 – $19.00 |
| Extremes incl. outliers | $3.00 – $52.30 |
| Completed sales | 14 |
By Brand
| Brand | Median | Range | Sales |
|---|---|---|---|
| GE | $7.23 | $6.00 – $15.42 | 6 |
By Condition
| Condition | Median | Sales |
|---|---|---|
| NOS | $7.30 | 10 |
| used | $4.00 | 3 |
Per-tube prices from completed sales, 2026-07-14 to 2026-09-11. Matched pairs and quads are divided out. See the price index for how these move over time.
Datasheets
Original manufacturer datasheets for 2D21, hosted by Frank Philipse's Electron Tube Data sheets.
| Manufacturer | Designation | Datasheet |
|---|---|---|
| Mazda-Belvu | 2D21 | PDF (686 KB) |
| Sylvania | 2D21 | PDF (404 KB) |
| RCA (HB3) | 2D21 | PDF (219 KB) |
| Brimar | 2D21 | PDF (103 KB) |
In the Archive
Documents held here and used to write this page.
- .. CARACTERISTIQUES GENERALES
5 further designations appear alongside 2D21 in the literature but below the evidence threshold used here, so they are not listed as equivalent.