A post by
ckwsp101_tv gives a very useful chart that converts SiliconDust Signal Strength % readings to dBmV
https://forum.tvfool.com/showpost.ph...2&postcount=33
Code:
Found on SiliconDust forum
SS% dBmV
0% -60 dBmV
5% -57 dBmV
10% -54 dBmV
15% -51 dBmV
20% -48 dBmV
25% -45 dBmV
30% -42 dBmV
35% -39 dBmV
40% -36 dBmV
45% -33 dBmV
50% -30 dBmV
55% -27 dBmV
60% -24 dBmV
65% -21 dBmV
70% -18 dBmV
75% -15 dBmV
80% -12 dBmV
85% -9 dBmV
90% -6 dBmV
95% -3 dBmV
100% 0 dBmV
I decided to invert the chart, putting 100% at the top. I first learned how to measure the strength of TV signals in microvolts with an old borrowed Sadelco meter.
I next bought a meter that read in dBmV which used the 0 to -30 scale.
An then, I had to learn how to use Noise Margin and dBm values that were in TVFool reports:
Code:
SiliconDust HDHR Signal Strength Conversion Chart
SS% dBmV dBm
100% 0 dBmV -49
95% -3 dBmV -52
90% -6 dBmV -55
85% -9 dBmV -58
80% -12 dBmV -61
75% -15 dBmV -64
70% -18 dBmV -67
65% -21 dBmV -70
60% -24 dBmV -73
55% -27 dBmV -76
50% -30 dBmV -79
45% -33 dBmV -82
40% -36 dBmV -85
35% -39 dBmV -88
30% -42 dBmV -91
25% -45 dBmV -94
20% -48 dBmV -97
15% -51 dBmV -100
10% -54 dBmV -103
5% -57 dBmV -106
0% -60 dBmV -109
Comment by Calaveras:
https://www.avsforum.com/forum/25-hd...l#post58705364
Quote:
Originally Posted by Calaveras
The HDHR shows 100% Signal Strength at 0 dBmV or -48.75 dBm and greater. The TV dynamic range runs up to around -8 dBm or 40 dB stronger. It's too bad they chose to set 100% to 0 dBmV because it's not helpful in seeing how strong a signal really is. In many cases 100% on the HDHR is no problem at all for the TV tuner.
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The latest unit is dBuV/m (dB microvolts per meter) field strength in reports from rabbitears.info.
https://en.wikipedia.org/wiki/Decibel
Quote:
dBμV/m, dBuV/m, or dBμ
[57] dB(μV/m) – electric field strength relative to 1 microvolt per meter. The unit is often used to specify the signal strength of a television broadcast at a receiving site (the signal measured at the antenna output is reported in dBμV).
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The field strength of the signal is just before it touches the antenna. The signal at the output of the receiving antenna is measured in dBμV or dBmV (which can be converted to dBm), which are measurements of signal power.
Code:
SiliconDust HDHR Signal Strength Conversion Chart
SS% dBmV dBm NM dB* dBuV/m**
NA 40 dBmV -9 82 121
NA 30 dBmV -19 72 111
NA 20 dBmV -29 62 101 Signal strength is important but
NA 10 dBmV -39 52 91 the goal with HDHR readings
100% 0 dBmV -49 42 81 is to maximize Signal Quality
95% -3 dBmV -52 39 78 (SNR) and have 100% Symbol
90% -6 dBmV -55 36 75 Quality
85% -9 dBmV -58 33 72
80% -12 dBmV -61 30 69 Conversion factor used for
75% -15 dBmV -64 27 66 dBmV to dBm: -49
70% -18 dBmV -67 24 63
65% -21 dBmV -70 21 60 Conversion factor used for
60% -24 dBmV -73 18 57 dBm to NM: +91
55% -27 dBmV -76 15 54
50% -30 dBmV -79 12 51 Conversion factor used for
45% -33 dBmV -82 9 48 UHF dBm to dBuV/m: +130
40% -36 dBmV -85 6 45
35% -39 dBmV -88 3 42 Signal Margin in a rabbitears
30% -42 dBmV -91 0 39 report is similar to Noise
25% -45 dBmV -94 -3 36 Margin in a TVFool report
20% -48 dBmV -97 -6 33
15% -51 dBmV -100 -9 30 * NM (Noise Margin)is used in
10% -54 dBmV -103 -12 27 TVFool reports
5% -57 dBmV -106 -15 24 ** dBuV/m is used in reports
0% -60 dBmV -109 -18 21 from rabbitears.info
rabbit73 Oct 25, 2019
**dBuV/m is an approximation valid for UHF signals. Report values
for VHF have a negative correction factor applied to allow for higher
noise levels on VHF. This ranks VHF signals lower in the report.
The last two attachments are the same chart. The Chart4-120.JPG is a little larger because it is at 120% of a BB code image in a post.
This is the Chart5-115 image for comparison with the original code image above:
