DMX741U vs DMX741Standard?

[Lone Gunman]

I've had a DMX-741U for a month or so now and have had some problems with Ku feeds that I think "might" be related to the funky LO numbers on the Ku setup. Almost every time I scan Ku I get TP numbers well up into the 12500 range with SRs of 20000 which NEVER produce any video or audio. Cband side of this LNBF seems to work very will but Ku is another story.

So since I'd been toying with the idea of using one of these on my current 10ft Winegard dish, I ordered a "Standard" version last night that will use the standard LO of 10750 for Ku scans. I'll swap that U version out on my SAMI first and see if the funky TPs go away then try one of the two on my Big dish after that. It's a pretty easy swap as they will fit in the Chaparral scaler ring and there is a setting in my 4DTV receiver to use them for whatever analog signals that "might" be available. Of course I do have both a Pansat 3500 and an AZBox Elite slaved to that 4DTV receiver too. Be good to see some A/B test results between the Norsat C/Ku LNBs and that DMX on that Winegard dish.

Yup, more toyz to play with! Because I can! Heh, as if the drag racing I do wasn't already expensive enough???

 

[Mr Tony]

Almost every time I scan Ku I get TP numbers well up into the 12500 range with SRs of 20000 which NEVER produce any video or audio.

those are DBS TP"s...if you're near 72, 77, 82, 91, 110, 119 that will happen.

You mention a Pansat 3500 which I can confirm will do this. The issue is such (and it will happen with the standard too).
With a Universal LNB Pansat receiver will blind scan from 950-2150 IF frequency. This is 11550 to 12750 on the KU Band (to figure it out, take the IF frequency and add it to the LNB frequency). When you blind scan in the left top corner it says IF 950 and works its way up when it scans.
With a standard it will scan from 950-1600 (11700-12350) so if you're near a DBS sat it will pick up some of those transponders at low signal. Since everything is encrypted (and the signal is too low) no channels show

Most receivers blind scan is done by frequency so it will stop at 12200 (the end of KU). Pansats do not and this is one of their quirks. If I remember right the only LNB the Pansat stops early (1600) is a KU Standard. Even the C-Band LNB's they scan down to IF frequency 2150

 

[Lone Gunman]

Thanks Ice. Had mentioned that on another post or two but never got an explanation as to where those numbers came from. Since I spend quite a bit of time on 91 watching and testing stuff I guess that's where those numbers came from then.

On another note, universal LNBF Ku scanning with the Pansat seems to take a long time, much longer than for C stuff so hopefully the "Standard" LNBF will speed up those scans. That "U" version works really well for C stuff on my SAMI and I'm anxious to see how one will work with that 10 ft Winegard.

Was looking at the price on those Invacom QPF-031s again yesterday and it's hard for me to understand why they are double the price of a QPH model? And then you have to have the feedhorn to go with the QPF, which is another $35?

I guess I've got enough toyz for now as the engine is out of the race car and from what it looks like right now, I've got to spend right around $3000 in that before next spring.

 

[Mr Tony]

Universal LNB's have to scan 2 bands...a low band (10700-11700) and the high band (11700-12200). A shortcut is to set up the menus as STANDARD (instead of Universal) and LNB LO 10600 and turn the 22k ON (instead of 9750/10600 and 22k says auto).....then it will scan only the high band which is what all the regular sats use. A couple over the Atlantic need Universal

 

[Lone Gunman]

Man, you're just full of answers today, hey! I'll have to go into the antenna setup list and change that on one sat to see how it does. Thanks!