Circular Ku Channels

[Andrew K]

Help - Need Correct Settings for Invacom QPH-031



The picture above shows my settings. I'm using the Invacom QPH-031 which I just installed today, but I haven't been able to lock into any circular signals. I've figured out to how receive the linear signals using an LNB frequency of 10750 and 22K off, but still no luck with any circular. I'm using a diseqc switch with the linear going into 0 Khz and circular into 22 Khz. The LNB is a standard 10750/11250 LNB.

 

[Magic Static]

Wrong LNB for that satellite. That's the only sat that needs an LNB with these settings Circular but a LO of 10750. You should get some transponders on the upper end but not all with the Invacom

 

[primestar31]

Set DiSEqC 1.0 to ON

 

[Andrew K]

For DiSEqC 1.0, the options are... Port1, Port2, Port3, or Port 4. I'm not sure what any of that means.

I set the LNB frequency to 10750 for 118.8W, and it's showing a signal for the scrambled channels. Is there anything circular that I can try for with my Invacom? Should I change any of the settings I have shown in the picture?

 

[SatelliteAV]

If you wish to receive linear transponders from the 11700 - 12200mhz band connect to the L (linear) output and set the LO to 10750. To receive circular 12200 - 12750mhz connect to the C (circular) output and set the LO to 11250. MagicStatic is correct. You might receive a few of the circular transponders just below 12200,. The QPH-031 circular frequencies would be used for satellites such as 110w or 119w, but you will only find a few channels in the clear on those satelllites.

The 22khz and DiSEqC settings are not used unless you add a switch inline.

 

[KE4EST]

If that switch has 0K and 22K ports than it is a 22Khz switch and not a DiSEqC switch. So leave your DiSEqC settings to disable.

 

[Andrew K]

Are there ANY circular channels that this LNB can pick up ITC??? I can't find any. And I'm getting all the linear channels scanning in even though I'm scanning a circular satellite with all the circular settings. What's up with that? Like when I scan 110W, I'm getting the linear Saskatchewan channels from 111W. And when I scan 82W, I'm getting RTV, Tuff TV, and PBJ from 83W.

 

[Andrew K]

I bought the Invacom QPH-031 LNB and installed it yesterday. Does anyone know of a good circular channel ITC to test this out on? Or does one even exist? I've scanned some TPs from the list, but still nothing. I tried Sathint, but still no luck. I'm beginning to wonder if I even have the circular side installed properly. I have the linear channels working. Isn't there a DISH or DirecTV promo channel ITC that this thing will work on??

 

[KE4EST]

Yeah you should get a couple channels on Echostar 14 @ 119W. But then again they are so strong you can get them on linear too np.

 

[Mr Tony]

12457 (R/V) 20000

Dish promo channel

 

[Mr Tony]

merged threads together

 

[Andrew K]

When I do a scan for circular channels, the receiver only is able to find linear channels, and it shows the frequency as 500 MHZ higher. I still haven't locked on to anything circular.

Like for example, when I scan 82W with all the circular antenna settings, it scans in the linear channels from 83W like RTV with the frequency showing as 12235 instead of 11735. Is that normal? Does my LNB have a problem? I noticed it's a standard LNB 10750/11250... that's a frequency difference of 500 MHZ.

 

[SatelliteAV]

Direct connect to the "C" output of the LNBF. Set the STB LO to 11250. Blindscan 82w, 91w,110w, 119w, etc. You will find circular transponders with frequencies between 12200 and 12750mhz.

The QPH-031 LNBFs have very tight frequency drop off on the Circular and Linear outputs. Since these outputs are hardwired to the respective polarity circuits, there will be very little portion of the other frequency range that could be logged. You might scan a few frequencies below 12200 on the "C" output and a few frequencies above 12200 on the "L" output. The reception of linear with the circular circuits and circular with the linear circuits is possible, but the signals are attenuated by approximately 3dB (each 3dB is a doubling of power). You will see some transponders from the opposite polarity, but they will be much weaker!

 

[Magic Static]

One other important note. Most of the transponders on the DSS sats use a modulation your receiver can't do, 8PSK with Turbo FEC, most commonly refered to as Turbo 8PSK. Rarely, hidden channels will show in the clear for a short time, but for the most part there is nothing there to watch.
Iceberg provided the coordinates for Channel 101 on Dish119. That is like the only ITC channel to use for testing the LNBF.

 

[farwest5050]

Hey MagicStatic,hope you be fine there.Question: When we remove the dielectric plate from a 621 lnbf we are looking for linear polarity.So we are not able to lock circular polarity.Does that work on C band only or does it affect KU band also?

 

[SatelliteAV]

The dielectric plate in the C/KU is only for C-band. C/KU LNBFs do not receive circular KU-band( with or without the dielectric slab).

 

[phlatwound]

The dielectric plate in the C/KU is only for C-band. C/KU LNBFs do not receive circular KU-band( with or without the dielectric slab).

Why is that? Never gave it much thought but I had (incorrectly) assumed the slab would convert the feed to circular reception in both bands.

 

[SatelliteAV]

Why is that? Never gave it much thought but I had (incorrectly) assumed the slab would convert the feed to circular reception in both bands.

Just the design and placement of the dielectric slab in the feedhorn and the position of the KU probes within the cavity.

 

[phlatwound]

Just the design and placement of the dielectric slab in the feedhorn and the position of the KU probes within the cavity.

Ah so, thanks.

 

[Andrew K]

I swear something is wrong with the LNB. When I do a circular scan, it only picks up the strongest TPs, which I can already pick up with my linear LNB anyways. On a few of the circular TPs it can pick up, the frequencies are way too high. Like for example it picks up a TP on 13150 MHZ!!! All the TPs are 500 MHZ higher than they should be. Is that normal?