What's The "proper" way to mount an LNB?

[pdnettles]

Where should the LNB be positioned in the clamp? Close to the "lens" or closer to end of the arm that is further from the dish?
Could this positioning effect the focal point to the extent of not receiving a signal at all?

P.D.

 

[charper1]

Set it all the way back into the clamp, away from the reflector.

 

[Mr Tony]

correct
If you are using a motorized unit, put the LNB as far back as you can

BUT if its a fixed dish...sometimes moving it closer helps. It did with my fixed Dish at G10..thats about 1/3 way up

 

[pdnettles]

Thanks Guys

I now have a new problem and need help.

Yesterday I installed an Invacom universal LNB hoping to improve my reception and options.
I have two Rcvrs, a Coolsat Pro & a US electronics ORB 7500. I use the ORB for analog feeds from G10R, and it was working good with the single "normal" LNB (IO Freq 10750) I had. After installing the Invacom, I changed the LNB freq to "universal" on the Coolsat & it receives digital better ( more channels than I had), but I totally lost the analog reception I had been getting with the ORB.

I have looked all through the set-up & manual for the ORB and can find no place to change the LNB Freq. You only have the option of selecting LNBF, +18v, or 524 for the RF input. What have I done wrong, or what am I missing?
I wonder if the ORB is compatable with a "universal" LNBF? How would I know? How do I know if the Invacom is capable of analog reception?

I'm new to this satellite stuff and this forum. I have been doing a lot of studying on it, and am trying to catch up, but I've hit a snag here. Hope someone can give me a little help.

PD

 

[SatelliteAV]

There is no set position that the LNBF should be installed. While viewing the signal strength and the signal quality meters make small adjustments on the placement towards or away from the reflector surface. You will find the sweet spot where the signals from the parabola merge. This is know as the F/D or Focal Distance of the dish.

Also experiment with the rotation of linear LNBFs. Sometimes a LNBF that physically appears to be positioned correctly has the probes slightly of axis and a higher quality signal can be obtained.

An LNB is only and amplified receptor of signals. It will not differentiate between an digital or analog signal. It will pass both digital and analog signals. The Invacom is an Universal LNB, so if the ORB does not have the ability to select the High or Low Band LO settings, it will need to be slaved off of the CoolSat, which is capable of controlling an Universal LNB.

 

[pdnettles]

Hi Brian, and thanks for the answer,

I thought I was "slaving" the ORB off of the Coolsat by using the "loop through" connector.
I have tried tuning the Coolsat to a Xponder of the same polarity as the analog one I am trying to receive, but it still doesn't work. I know it must be the LO Freq causing the problem, because I hopped on the roof, changed the LNB back to a Std, and received the analog signal OK.
How do I "slave" the universal to work?

Thanks,
PD

 

[SatelliteAV]

The loop out is one of the ways to slave the Analog. The other would be to use a Splitter rated 2-3K MHz and DC block the side feeding the analog.

The CoolSat must be on a similar (same) frequency and polarity to assure that the LNBF 22KHz is switched to the proper band. If the Coolsat is set to the Low Band and the analog needs to see the high LO switch then it would be looking at a frequency that is 850 Mhz lower than where the signal actually is.

 

[pdnettles]

How do I DC block the side feeding the analog if I use a splitter?

PD

 

[boomer_106]

I was wondering that myself so I am just subscribing to this thread.

 

[pdnettles]

Hey Brian or Iceberg,

How do I DC block the side feeding the analog receiver if I use a splitter and just what is that doing?

PD

 

[Mr Tony]

get a DC block from the Rat Shack...they're like $2....correction..$3
put it on the output of the splitter side goig to the analog receiver.

What this does is makes it so both the analog and the Coolsat don't fight over which polarity to have the LNB. The Analog would have the same polarity as what the Coolsat would if it was on (the Cololsat). If its off, you should be able to select either polarity on the analog. This is how I use to have my analog hooked to the Viacast (before I got a receiver with a loop out)

http://www.radioshack.com/product.asp?catalog_name=CTLG&product_id=15-1259

 

[pdnettles]

Thanks Ice,

Did you ever come up with why the loop through isn't providing the analog with the 22KHz? Would the DC block do this? If not is there some device I can put in the line that will?

PD

 

[Mr Tony]

no I didnt

What is weird is normally the analog (when using the loop out) would be on the same polarity, and when using a Diseqc switch, satellite as the DVB receiver...so if the 22K is on, it should acknowledge it too.

 

[pdnettles]

OK.

Keep it in the back of your mind & if you think of anything let me know. In the meantime, I'll just keep trying different stuff, even tho I've just about exhausted all my options.
I did order a two LNB holder for the dish, so that should do the trick.

Thanks again,

PD