Can't get KU with BSC621-2 C-ku LNBF

[ploki]

I have a 10 feet mesh dish and I'm using a Pansat 2500a.

I bought the BSC621-2 (didn't know wich was better between the two) and I have a real strong (nearly 100%) C Band signal but cannot retreive anythig good from KU band.

I've tried almost all LNBF positions...

Maybe a setting somewhere?

Any ideas...

[rainman]

Originally Posted by ploki

I have a 10 feet mesh dish and I'm using a Pansat 2500a.

I bought the BSC621-2 (didn't know wich was better between the two) and I have a real strong (nearly 100%) C Band signal but cannot retreive anythig good from KU band.

I've tried almost all LNBF positions...

Maybe a setting somewhere?

Any ideas...

make sure you have the lnb set to universal LO freq 9750/10600.

[wejones]

Also, I think to get Ku you have to set the diseqC switch control on the receiver to port #2 . #1=C band, #2=Ku.

[bill190]

The C-band LNB on the BSC621-2 also has a diseqc switch.

The way this operates is to tell your receiver for C-band use to switch to diseqc 1 or LNB 1. Or for Ku use to switch to diseqc 2 or LNB 2.

On my receiver, if there is a satellite which has both C and Ku, I have two separate listings of the same satellite. Say satellite_xyz_C and satellite_xyz_Ku. Only C frequencies on the C listing and only Ku frequencies on the Ku listing.

For the C satellite listing, I set the LNB to the proper L.O. for the C LNB *and* set the switch to use C by selecting diseqc 1 or LNB 1.

For the Ku satellite listing, I set the LNB to the proper L.O. and Low L.O. for the Ku LNB *and* set the switch to use Ku by selecting diseqc 2 or LNB 2.

For testing, you can also run a cable from your receiver to just the Ku LNB on the BSC621-2.

[elgemcdlf]

If you are running two individual lines from the lnbf you do not need to worry about the DiSEqC switch (internal) have you verified you have the cables hooked up correctly? How old is the dish? If the holes in the mesh are to large you will not get Ku.

I would line up on a sat that had both C and Ku. Peak for the C Band signal and switch to Ku and peak. You may be catching a sidelobe with C Band. Especially with a 10' dish.

[lumpkin666]

I haven't done much tweaking on my BUD setup yet, but I found the KU side (when good on the C-Band side) to be weak. It may be my alignment, parabola, skew, etc. I dunno. I have seen more than one individual comment, however, that best reception of both bands on the same sat requires a bit of a bump of the dish east or west a degree or so.

[elgemcdlf]

Originally Posted by lumpkin666

I haven't done much tweaking on my BUD setup yet, but I found the KU side (when good on the C-Band side) to be weak. It may be my alignment, parabola, skew, etc. I dunno. I have seen more than one individual comment, however, that best reception of both bands on the same sat requires a bit of a bump of the dish east or west a degree or so.

If you are using a Corotor the location for C Band will be different than Ku. If you are using the BSC - lnbf's it should be the same location. If you are working with the BSC lnbf you can peak C Band. Then switch to Ku and peak the sat. You should find your C Band is perfect at this point. A problem with larger dishes are sidelobes. Some so strong you will believe you are correctly aligned.

I use my DVB receiver to peak sats as I find it more sensitive in readout. Peaking Ku on the DVB receiver greatly improved my C Band readings on the 4DTV. When readings did not improve it still proved more stable (less pixalation).

The problem with trying to peak Ku from C Band is C Band will be watchable when you have no Ku. I have never seen it the other way around. C Band first (easier), Ku second, all should be good.

[wejones]

Originally Posted by elgemcdlf

If you are using a Corotor the location for C Band will be different than Ku. If you are using the BSC - lnbf's it should be the same location. If you are working with the BSC lnbf you can peak C Band. Then switch to Ku and peak the sat. You should find your C Band is perfect at this point. A problem with larger dishes are sidelobes. Some so strong you will believe you are correctly aligned.

I use my DVB receiver to peak sats as I find it more sensitive in readout. Peaking Ku on the DVB receiver greatly improved my C Band readings on the 4DTV. When readings did not improve it still proved more stable (less pixalation).

The problem with trying to peak Ku from C Band is C Band will be watchable when you have no Ku. I have never seen it the other way around. C Band first (easier), Ku second, all should be good.

Whether using a Corotor or BSC, the Ku aim should be the same as that for C-band, and most people recommend using Ku whenever possible for alignment. Sidelobes can be a problem, and I have that problem, but if you have a good new dish it's usually not too bad. My dish has gotten bad since it is old, and has been mistreated over the years (by me).

However, I think the big reason for C band showing up at a different place from Ku is having the feed at the wrong focal length. When the feed is at the wrong focal length, instead of focusing at a spot, I think Ku focuses in a donut shape, meaning that Ku will appear to peak at a different point. I have this problem too right now, but I intend to fix that when the weather clears up. Ku used to focus at exactly the same point as C band with my dish, but somehow I got it out of whack. Focal length is really hard to adjust on my dish because some of the bolts you have to get to to change it properly are about 14' up in the air.

[Corey]

Focal length is really hard to adjust on my dish because some of the bolts you have to get to to change it properly are about 14' up in the air.

Here's a nice little de-rail / rant.

I find Ku-dish hardware to be very poorly designed for adjustability. They are made well enough, from decent quality metal, paint, etc, but man... I find that adjusting them to be really painful.

To me, there ought to be ONE bolt to turn to finely adjust the elevation... not two where I have to support the dish with one hand while tighting and loosening two bolts, and as soon as I let go, the dish settles a bit off from where I wanted.

Would it really be that much more expensive to supply a better elevation mechanism?

I also find the the azimuth hardware and 45degree pole mount to be crude too, but that's another story.

[ploki]

Thank you all for your time and help.

I just want to add some precisions.

The mesh holes on my dish are very small and a pen wouldn't go through one. I've tried to bypass the internal DISEqC switch by using an individual line and it didn't change anything. My previous setup was a feedhorn with a modified scalar ring that made me put a Ku lnb beside the feedhorn and the ku signal was rescpectable. But I was hoping to uprade it a lot with BSC621-2.

Can sombody tell me the differece between the BSC621 and BSC621-2?
Wich one's better?

I will try all your suggestions this weekend.

Thanks again.

[rainman]

Originally Posted by ploki

Thank you all for your time and help.

I just want to add some precisions.

The mesh holes on my dish are very small and a pen wouldn't go through one. I've tried to bypass the internal DISEqC switch by using an individual line and it didn't change anything. My previous setup was a feedhorn with a modified scalar ring that made me put a Ku lnb beside the feedhorn and the ku signal was rescpectable. But I was hoping to uprade it a lot with BSC621-2.

Can sombody tell me the differece between the BSC621 and BSC621-2?
Wich one's better?

I will try all your suggestions this weekend.

Thanks again.

the 621 is a standard ku lnb with lo freq of 10750 will work with the 4dtv and analog receivers on ku. the 621-2 is universal ku lnb with lo freq of 9750/10600 works well on the sats out over the Atlantic. as to which one is better depends on what you are going to use it for.

[ploki]

Thanks Rainman!