Quality loss question

[icedown]

I've got my noaaport system fully up and running finally. I'm having a little problem with signal quality though. I can't seem to get it over about 95%. I'm using good quality coax, but about a 100' run of it. Voltage at the LNB(horizontal) is 17v. Could that last little bit of quality be because of the long run? I spent 3 hrs out there today trying to fine tune, both where it's pointing and the postion of the feedhorn but was able to gain very little. Also, does running the coax near power conduits affect the signal, or even rolling the excess into a loop?

 

[skysurfer]

I've got my noaaport system fully up and running finally. I'm having a little problem with signal quality though. I can't seem to get it over about 95%.

what am I missing? 95% sounds like a very good signal strength. Are you not able to lock onto the noaaport signal?

what size reflector are you using? It could be an issue if you aren't getting lock.

 

[icedown]

I'm using a 10' sami mesh polar mount with a norsat 8515 lnb and chaparral super feed feedhorn. I can lock fine. 95% quality may sound good but it's just not enough for data. I'm getting quite a few mangled packets. I am not effectivly receiving anything over about 500kb in size due to lost packets.

 

[Hermitman]

Is this on just one data channel or on all four? Have you checked that the decoder parameters are set up as required? 100 ft of coax is not really that long and shouldn't have a large effect on your signal. Running next to power lines shouldn't be a problem if you have good quality coax and its properly grounded. Good luck.

 

[B.J.]

what am I missing? 95% sounds like a very good signal strength. ...

I agree that 95% should be fine for virtually any signal, particularly with a Twinhan, which generally gives low quality readings. A 95% quality should give you virtually no "uncorrected" errors. There will always be errors, but with the FEC you shouldn't get many that aren't corrected.

I would think that it's more likely a problem in the computer side of the setup. For example, I know I've mentioned this before, but not sure if in the NOAAPORT threads, but I've found that my Twinhan conflicts with SATA hard drives. This becomes very evident if you run TSREADER, or any other program that shows any error/lock statistics. I would have a transponder locked, and giving zero uncorrected errors, then I would start a sizeable file transfer to or from my SATA drive (at the time I had about 3 internal hard drives, one of which was SATA). Any time that SATA drive was active, the Twinhan would basically stop reading data. The error numbers would start flying, and it would be trying to re-sync/re-lock, and I'd eventually lose lock completely if the data transfer took long enough. As soon as the data transfer was finished, it instantly went back to error free reception.
This was NOT a function of the CPU being over-taxed, it was a clear conflict with the SATA drive. If the transfer was between any other drives, I wouldn't see any errors.
Anyway, I'd recommend pulling the transponder up with TSREADER, and watch the error categories while you transfer some large (like a 2 GB video file) file between drives on your computer. I'll bet that some device or process on your computer is interferring with the Twinhan. This could be why the problems are related to how big the files are, in that when saving a big file, the hard disk process has a higher priority,... or, perhaps the computer itself isn't fast enough to process the data, and not enough processor time is devoted to the Twinhan.