A little DiSEqC Switch Help Please

[JAS]

My setup is per the attached with a 4DTV DSR922 and a Pansat 9200HD with the -S2 board. The splitters have DC blocks on the MPEG Receiver side.

The problem I have is associated with the DiSEqC switch. For some time I have not been able to get a strong enough signal to lock the LPB stations on AMC-21. I decided to change out the DiSEqC switch. When I installed the new switch signal went up to 80 and quality went to the low 90's. I thought this is great, But, when checking other satellites find that I lost some C band -S2 signals.

I have 4 DiSEqC switches 2 2 port and 2 4 port. I do not know the brand of any of the switches, all the tags are gone. When I use either of the 2 port switches I gain the LPB signal and quality but loose signal and quality on some C bald -S2 signals. When I use either of the four port switches I loose signal and quality on the LPB stations but gain back the -S2 signal and quality on C band. I have tried switching ports but is always the same.:rant::rant:

Any suggestions

 

[Anole]

I see your quandry.
But yes, I do have a thought.
This has been posted before, so I'm not just making it up.
In some circumstances, a hot signal from the deselected input of a switch, will still get through.
This could cause interference with the desired signal from the selected input.

Select a Ku band signal that doesn't seem reliable.
Now, move the C-band dish.
Did the Ku change at all?

Next, select the desired C-band signal that is not acceptable.
Move your Ku dish to see if the C-band signal changes.

This all assumes you haven't blown up all your diseqc switches by connecting and disconnecting them with power on!

Not that I have any expectation that it would work, but you might try a 22khz switch instead of your diseqc, I suppose.

 

[JAS]

Select a Ku band signal that doesn't seem reliable.
Now, move the C-band dish.
Did the Ku change at all?

Moving East or West just looses more signal after a few clicks.

Next, select the desired C-band signal that is not acceptable.
Move your Ku dish to see if the C-band signal changes.

Same as above

This all assumes you haven't blown up all your diseqc switches by connecting and disconnecting them with power on!

Always disconnect the power so I think the switches are ok.

Not that I have any expectation that it would work, but you might try a 22khz switch instead of your diseqc, I suppose.

Might be time to get a 22khz switch . Also, is there one brand of DiSEqC switch recommended over others.

Thank You

 

[Lak7]

If you don't need Ku to the 4DTV, remove the splitter, and connect direct to the Pansat switch.

What type of Feed / LNBs are you using?

 

[JAS]

If you don't need Ku to the 4DTV, remove the splitter, and connect direct to the Pansat switch.

The only reason I need KU to the 4DTV is to fine tune the signal on ku only satellites. But I guess I could do the same using the Pansat signal meter. On C/KU satellites I fine tune using C band.

This brings up another question. If I connect the Pansat directly to the KU LNB could I go to the Anik A1 and A2 satellites without fear of loading the maps in the 4DTV thus exceeding the TDT Record of 1920. I'm at 1800 now. Or will the maps load from the C band side too.

What type of Feed / LNBs are you using?

The feed horn is an ADL. C-band lnb is a Chaparral. Ku lnb is a Norsat. I do not remember the specs on any of the above (to cold to check right now) but they were the best or at least the most expensive 18 years ago.

Thank You

 

[Lak7]

Or will the maps load from the C band side too.

That, I dunno.

Here's something to try:
Connect the 4DTV to the Loop-Out of the Pansat
Connect the C Band LNB to DiSeEq Port 1, and Ku to port 2.
See if you still get C Band with the Pansat in Stand By
I don't know if the Pansat can fully power your LNBs.

 

[pendragon]

You are likely having signal level problems. The Pansat 9200HDs are a bit on the deaf side. A low-loss 22 kHz switch might solve the problem, but it's possible a couple of good quality amplifiers at the dish will be necessary.

 

[JAS]

That, I dunno.

Here's something to try:
Connect the 4DTV to the Loop-Out of the Pansat
Connect the C Band LNB to DiSeEq Port 1, and Ku to port 2.
See if you still get C Band with the Pansat in Stand By
I don't know if the Pansat can fully power your LNBs.

Connecting as above. There is no C band while in Stand By. Also, the Loop out is shut down while in Stand By.

 

[JAS]

You are likely having signal level problems. The Pansat 9200HDs are a bit on the deaf side. A low-loss 22 kHz switch might solve the problem, but it's possible a couple of good quality amplifiers at the dish will be necessary.

This only occurs With the LPB -S2 mux On AMC-21 and another C band -S2 mux on an unmentioned satellite (not in The List or Lyngsat). I get C band and KU satellites from 50 degrees West to 139 degrees West and only those two muxes act like that. I'm stumped.

Thank You

 

[Lak7]

Did you try just connecting the Pansat with Switch, no Splitters, no 4DTV?

 

[JAS]

Yes. First I connected directly to the C band LNB 89 signal 96 quality on that -S2 MUX. Then moved the dish to AMC-21 and connected directly to the KU LNB 81 Signal and 92 quality on LBP.

 

[Lak7]

Add the switch, then check - note Quality readings
Remove Switch, add 1 Splitter and 4DTV - Check C Band, then Ku - note readings
Try the second splitter
See if you can narrow it down to 1 switch / splitter or combination there of.

 

[JAS]

Add the switch, then check - note Quality readings
Remove Switch, add 1 Splitter and 4DTV - Check C Band, then Ku - note readings
Try the second splitter
See if you can narrow it down to 1 switch / splitter or combination there of.

I'll have to try that later. Need to get on the road.

I'm starting to think that this is just another of the many Pansat software problems.

Thank You

 

[Lak7]

I'm guessing bad / poor splitters.

 

[pendragon]

This only occurs With the LPB -S2 mux On AMC-21 and another C band -S2 mux on an unmentioned satellite (not in The List or Lyngsat). I get C band and KU satellites from 50 degrees West to 139 degrees West and only those two muxes act like that. I'm stumped.

Yes, S2 is very touchy and susceptible to low signal levels on the Pansat 9200HD, particularly with the old S2 board. The new S2+ board is much better in this respect. The cure is normally to get a hotter level into the receiver. There is the lesser possibility that your LNBs have a bit too much phase noise for reliable S2 reception, and inserting anything into the signal chain cuts your margin to razor thin levels.

I would start with getting your signal levels up. It's cheap and should improve the 9200HD performance all-around. Replacing LNBs is usually more expensive.

 

[JAS]

Bingo

I'm guessing bad / poor splitters.

inserting anything into the signal chain cuts your margin to razor thin levels.

My splitters did not have a built in DC blocker. I was using a F type attached to the splitters. I found splitters with the blocker built in this fixed the problem.

Another problem I was having is when the temp drops below 20 degrees F I lost all -S2 signals and all KU when it dropped down somewhere below 0 degrees F . I not asking for it, but it would be interesting to see if the blocker caused that problem too. The normal low temp around here in the winter is in the low 20's so this is not a biggie. It's just been unusually cold.

Thank You

PS Good thing this is a hobby. I would not go through all this just to watch TV