Determining SNR

[eclas]

I'm using 2 hd Primes. I can see the graphics in the config utility but they just show percentages. I'd like to see actual db levels.
How can I accomplish this?
Thanks

[Crash2009]

There are a few Apps written for Ceton Tuners. I don't know if they run on your tuner.

As an idea, if you have a set top box (STB) from your cable co, there is a diag mode that will show you the dBmV.

[eclas]

thanks for the reply. no set top box. i'll hunt for the ceton app and see if works.
on a side note...
ref signal strength/quality numbers...if i have 100% strength and 72% quality with an amplifier and then remove the amp and get 89% strength and 84% quality I should NOT use the amp right?

There are a few Apps written for Ceton Tuners. I don't know if they run on your tuner.

As an idea, if you have a set top box (STB) from your cable co, there is a diag mode that will show you the dBmV.

[Crash2009]

This one is a pretty good read..... http://www.thegreenbutton.tv/forums/vie ... 424#p44424

Contains links such as this one.....http://www.cetoncorp.com/support/index. ... -explained

You'll be an expert in no time. You are all ready half way there.....

"if i have 100% strength and 72% quality with an amplifier and then remove the amp and get 89% strength and 84% quality I should NOT use the amp right?" there is not enough info there to decide that one.

[richard1980]

I'm using 2 hd Primes. I can see the graphics in the config utility but they just show percentages. I'd like to see actual db levels.
How can I accomplish this?
Thanks

5% = 3 dB

[glugglug]

Actually, 3dB is closer to 50%.

dB is a logarithmic scale. Every 10dB is a 10x multiplier in the signal strength. x dB = a ratio of 10^(x/10). It would be pretty strange to list this as a percentage, so I don't know what those are.

[Crash2009]

So much for my logic. I was figuring 100 % signal was 0 dBmV. 0 % signal would be about + or - 15 dBmV. 50 % signal would get me about + or - 7.5 dBmV.

[richard1980]

Actually, 3dB is closer to 50%.

https://www.silicondust.com/forum/viewt ... 43#p108040

[eclas]

Thanks crash, I read that and understand the concepts. However my problem still exists. How do I get a db reading and snr numbers rather than percentages for an hd prime?

This one is a pretty good read..... http://www.thegreenbutton.tv/forums/vie ... 424#p44424

Contains links such as this one.....http://www.cetoncorp.com/support/index. ... -explained

You'll be an expert in no time. You are all ready half way there.....

"if i have 100% strength and 72% quality with an amplifier and then remove the amp and get 89% strength and 84% quality I should NOT use the amp right?" there is not enough info there to decide that one.

[Crash2009]

Thanks crash, I read that and understand the concepts. However my problem still exists. How do I get a db reading and snr numbers rather than percentages for an hd prime?

Richards got the right answer, I just read all 3 pages in the link he posted. At present, your request is impossible. It can't be done with the current firmware. 100% is 0 dBmV. If your signal is too hot (+18 dBmV) the SD firmware will still show 100%. Everybody knows that if you are running +18 dBmV OR -18 dBmV you get no picture.

Get a Ceton or a STB and use it for a testing device.

[richard1980]

But you can convert the percentage to dB if the percentage is less than 100%.

dB = ((100 - Signal Strength) / 5) * -3

[eclas]

ok guys, thanks for all the info. It was enlightening.
I guess I'll live with the percentages (I can figure the strength from richard's formula (90% strength = -6db...but for snr I'll have to use the %).
My picture is ok 98% of the time. I just wanted to see what the actual numbers were when it 'burped'.

[Crash2009]

I just installed a HDHR3-CC. Looks like the Signal Strength and SNR is available by clicking on TunerStatus.