Tektronix 1705A 75Ω 50Ω, Operating Instructions DBm to v Conversion Reading in dBm

Operating Instructions

Table 2- 2: dBm to ￿v Conversion

Reading in dBm	￿v (75Ω)	￿v (50Ω)	Reading in dBm	￿v (75Ω)	￿v (50Ω)
---30	8660	7071	---105	1.540	1.257
---35	4870	3976	---110	0.866	0.707
---40	2739	2236	---115	0.487	0.398
---45	1540	1257	---120	0.274	0.224
---50	866	707	---125	0.154	0.126
---55	487	398	---130	0.087	0.071
---60	274	224	---135	0.049	0.040
---65	154	126	---140	0.027	0.022
---70	87	71	---145	0.015	0.013
---75	49	40	---150	0.009	0.007
---80	27	22	---155	0.005	0.004
---85	15	13	---160	0.003	0.002
---90	9	7	---165	0.002	0.001
---95	5	4	---170	0.001	0.001
---100	3	2	---175	0.000	0.000

Horizontal Scales The horizontal graticule scales are divided into ten major divisions, which are further divided into five minor divisions each. The horizontal scale corresponds to frequency, with the lowest frequency to the left. Note the arrow in Figure 2-4 that signifies that the frequency ascends toward the right. Both the -60 and -80 dB lines are subdivided with minor division marks. Traditionally, many spectrum analyzer measurements and specifications are between 6 and 60 dB.

The available sweep for the 1705A is 12 divisions long, which means that not all of the frequencies that it is capable of displaying can be displayed simultaneous- ly. Figure 2-5 compares the sweep length to the graticule. It shows the usable areas of the sweep, as well as the minimum and maximum frequencies of the two bands.

1705A Spectrum Monitor 2- 9