what are vacuum tubes made of

Keyword Analysis

Keyword	CPC	PCC	Volume	Score	Length of keyword
what are vacuum tubes made of	0.35	0.8	4696	30	29
what	0.89	0.5	5683	63	4
are	1.15	0.2	5543	55	3
vacuum	0.58	1	8996	18	6
tubes	0.96	0.1	6111	46	5
made	1.79	0.3	7207	96	4
of	0.64	0.4	1636	94	2

Keyword	CPC	PCC	Volume	Score
what are vacuum tubes made of	1.88	0.2	7914	3
are vacuum tubes still made	1.29	1	4864	29
how are vacuum tubes made	1.51	0.1	3074	46
american made vacuum tubes	1.21	0.2	6449	34
what were vacuum tubes made of	1.43	0.4	6052	22
where are jj vacuum tubes made	0.87	0.9	3461	41
vacuum tubes made in poland	0.1	0.1	8298	9
vacuum tubes made in usa	0.48	1	5057	5
where are vacuum tubes made	0.29	0.5	203	28
are vacuum tubes still manufactured	0.46	0.8	3575	51
are vacuum tubes still being made	0.26	0.9	4697	79
vacuum tubes still used	0.41	0.5	4905	26
are vacuum tubes still used today	1.44	1	255	90
can you still buy vacuum tubes	1.87	0.7	7726	3
who still makes vacuum tubes	0.2	0.6	6237	28
are vacuum tubes obsolete	0.66	0.8	794	11
what is not true about vacuum tubes	0.04	0.3	990	72
are vacuum tubes worth anything	0.19	1	821	39
us made vacuum tubes	1.02	0.3	630	68
where are vacuum tubes manufactured	0.25	0.9	2703	60
vacuum tubes were replaced by	0.93	0.7	476	25
vacuum tubes were eventually replaced by	1.79	0.5	8712	23
new vacuum tubes for sale	1.47	0.6	2412	20
what replaced vacuum tubes	1.34	1	9408	71