nOOb Symbol Rate question

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Tim Mostad

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Sep 16, 2005
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If I see a Symbol Rate published as 6.148936 then how do I enter those into my fta receiver since there is no decimal point and only 5 digits possible? My guess would be 6148.
 
I once wondered where that disconnect was introduced. It seems sources routinely spec a symbol rate in MSPS and FTA boxes want it in kSPS.

For this particular case, I have a genpix which, I would bet, would not lock if given 6148. It would need to be rounded correctly and told 6149.
 
griz game huh? ;)

I noticed they're back on the same sat as 2 weeks ago :)

yeah 6148 is the s/r...some commercial receivers go 5 digits out on the symbol rate
 
I noticed this got moved to the "C-BAND" satellite section. Wherever it goes is fine with me except this is happens to be a Ku band question. What it is *really* is a general FTA receiver question and I couldn't figure out which section it belonged in so I picked the one the at least mentioned FTA DVB. At least now I know where to go in the future!

Go Griz!
 
actually that was my goof. It should have gone in the main area. I was looking at your other thread that was here in the C-Band area so for some reason I moved it here
 
If I see a Symbol Rate published as 6.148936 then how do I enter those into my fta receiver since there is no decimal point and only 5 digits possible? My guess would be 6148.

Depending on the receiver, it might want a zero first: 06148 (For five digits)

yeah 6148 is the s/r...some commercial receivers go 5 digits out on the symbol rate

Tim,

Depending upon the receiver make and model, you may adjust the symbol rate and still retain a signal lock. I have never read any rule regarding how much you are allowed to deviate from the posted SR, but I have experimented with this on my own and it has proved to be a surprise. With a Coolsat 5000 receiver, the SR can be varied quite a bit.

Some receiver tuners are very sensitive to the TP frequency, however. This is especially true when you get into DVB-S2 tuners. Here, a 1 MHz difference in the TP frequency might make or break the signal lock where as the tuner in the Coolsat 5000 could retain a lock with up to 3 or 4 MHz deviation.

With the advent of HD and DVB-S2 signals, I perceive that everything has to be more stringent. Deviations in SR or TP frequencies may not be allowed. I have a speculation that blind scanning is much more difficult to implement with DVB-S2 receivers because of this.

I am sure that there is a lot more engineering aspects that need to be considered here for design.

RADAR
 
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