| Keyword | CPC | PCC | Volume | Score |
|---|---|---|---|---|
| how are vacuum tubes made | 0.59 | 1 | 2907 | 72 |
| are vacuum tubes still made | 1.61 | 0.2 | 8810 | 60 |
| american made vacuum tubes | 0.67 | 0.6 | 9708 | 19 |
| what were vacuum tubes made of | 1.27 | 1 | 1301 | 60 |
| vacuum tubes made in usa | 0.36 | 0.2 | 4251 | 81 |
| are vacuum tubes still being made | 0.1 | 0.9 | 9097 | 75 |
| where are jj vacuum tubes made | 1.73 | 0.1 | 5270 | 4 |
| vacuum tubes made in poland | 0.11 | 0.9 | 6266 | 39 |
| are vacuum tubes still manufactured | 0.52 | 1 | 8792 | 56 |
| vacuum tubes still used | 1.66 | 0.6 | 2087 | 97 |
| are vacuum tubes still used today | 1.68 | 0.6 | 9821 | 67 |
| can you still buy vacuum tubes | 0.58 | 0.5 | 440 | 4 |
| who still makes vacuum tubes | 0.47 | 0.9 | 4922 | 97 |
| are vacuum tubes obsolete | 0.74 | 0.5 | 6931 | 70 |
| where are vacuum tubes made | 0.8 | 0.3 | 7776 | 25 |
| what is not true about vacuum tubes | 0.88 | 1 | 9258 | 92 |
| are vacuum tubes worth anything | 0.93 | 0.6 | 7319 | 53 |
| us made vacuum tubes | 1.65 | 0.4 | 6919 | 19 |
| where are vacuum tubes manufactured | 1.85 | 0.9 | 1814 | 97 |
| vacuum tubes were replaced by | 1.36 | 0.3 | 3119 | 39 |
| vacuum tubes were eventually replaced by | 1.13 | 0.7 | 7369 | 80 |
| new vacuum tubes for sale | 0.44 | 1 | 2148 | 36 |
| what replaced vacuum tubes | 0.9 | 0.5 | 8053 | 1 |
