Root/atusd/tests/send-20100910

Source at commit df071c3398fed1aa6a3a64eea67b2d4b3a1f993d created 9 years 1 month ago.
By Werner Almesberger, New ECN about clock circuit of atusd boards. Measured (absence of) effect of adding an inductor to the clock line.
1Same test setup as for send-20100909. Board 100908-A was modified to have
2a 220 nH inductor in the C7 position, instead of a 0R resistor.
3
4Distant Local
5--------------- --------------- ---------------
6100813-red 100813-orange 100908-A (with inductor)
7
8TX 255, -91 255, -85
9TX 255, -90 255, -85
10TX 255, -91 -
11TX 255, -90 255, -85
12TX 255, -91 garbled
13
14- TX 255, -47
15- TX 255, -47
16- TX 255, -47
17- TX 255, -47
18garbled (-90) TX 255, -47
19
20255, -82 255, -43 TX
21255, -82 255, -43 TX
22255, -82 255, -43 TX
23255, -82 255, -43 TX
24255, -82 255, -43 TX
25
26Control experiment:
27
28100813-red 100813-orange 100908-B (unmodified)
29
30TX - 255, -83
31TX garbled (-91) 255, -86
32TX - 255, -86
33TX garbled (-91) 255, -86
34TX - 255, -86
35
36255, -83 255, -43 TX
37255, -84 255, -43 TX
38255, -85 255, -43 TX
39255, -84 255, -43 TX
40255, -84 255, -43 TX
41
42
43Summary
44-------
45
46Direction No inductor (1) With ind. (2) Change
47------------------------------- --------------- ------------ ------
48100813-red -> 100813-orange 255, -87 255, -91 -4 dB
49100813-red -> 100908-A 255, -88 255, -85 +3 dB
50100908-A -> 100813-red 255, -85 255, -82 +3 dB
51
52100813-red -> 100813-orange 255, -90 - ?
53100813-red -> 100908-B 255, -90 255, -86 +4 dB
54100908-B -> 100813-red 255, -87 255, -84 +3 dB
55
56(1) Data from send-20100909
57(2) Only 100908-A was modified. Changes in the measurements with
58    100908-B show inaccuracies of the test setup.
59
60
61Conclusion
62----------
63
64The differences observed are the same for the modified 100908-A board
65and the unmodified 100908-B board. The inductor therefore does not seem
66to have a significant effect on transceiver performance.
67

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