Help! no Sky Sports!

joeaverage

On a job recently. Quattro LNB and multiswitch already there. Checked levels out of MS, all four bands good.Connected Sky box to multi-switch. Everything hunky dory, except when I was leaving the customer selected Sky Sports, No Signal. checked levels at STB, good, one band a bit low. Must be the sky box, tried new sky box, still no sports, challenge also missing. Thought dish might be off, not that, alignment and LNB offset ok.

Plugged an Amiko X Finder in to the feed at the STB. Levels for this TP were a little lower than another site I had been at on another day, but only by a few dB. Selected sky sports and challenge TP and hey presto, pictures. Connected back in sky box, no signal. Plugged back in the meter, and connected the sky box to the loop out on the meter and hey presto pictures again.

Went directly next to the multi switch, connected the sky box directly to the switch with one meter of cable, pictures again. Rolled out a new cable run of similar length to the TV in question, no signal on the long cable run. Fitted line amp to the long cable run, no signal.

Tomorrow im going to try an amp between the multiswitch and the dish.

Can anyone throw some light on this one. Why are the pics present on the short cable run and not on the long one? loss in the cable? If so, why then does the meter manage to receive signal when its connected at the TV?

Oh God!!!!!

byte

How long is the run? And what grade of cable is being used?

I'd be inclined to consider the amps/voltage coming up the cable being insufficent for the multiswitch to do the switching, whereas there may be a higher ampage on the meter, so things are fine.

A long cable run, depending on distance and grade would have a fall off due to resistance.

joeaverage

The run is 40/50mtrs, regular double screened satellite coax, stuff I use all the time. Do you think heavier cable would do the trick, offering less resistance?

Wonder what about a different multi switch? I'm sure I have used the same cable on euually long runs with multi switches before. Only thing different here is the switch, like I said it was existing when I got there.

byte

What would you classify as regular coax? Would that be generic "RG6"?

It really should be proper "copper-on-copper" cable like Webro WF100 or Triax TX100, etc, which has copper dielectric, copper braiding and proper copper foil. Especially over a distance as long as 50m! In fact, maybe a heavier grade cable would be better over such a distance.

It's not just voltage you need to be concerned about, also the 22kHz tone which may also have faded over distance on low grade cable.

joeaverage

But like I said, I've used this same cable often on similar length runs with multi switches and had no problems. Could the multi switch be the cause? The cable I'm using is nothing special, €12.00 per 100m.

watty

Quattro correctly connected?
Try all frequencies that use same tone and voltage as Sky Sports.
Use a direct Quad LNBF bypassing Multiswitch to see if any other strange effect.

Multiswitches can do odd stuff if their PSU is faulty.

joeaverage

watty wrote: »

Quattro correctly connected?
Try all frequencies that use same tone and voltage as Sky Sports.
Use a direct Quad LNBF bypassing Multiswitch to see if any other strange effect.

Multiswitches can do odd stuff if their PSU is faulty.

If its the multiswitch why does it work ok when the meter is connected instead of the STB? That would suggest cabling is the problem. But I've used the same cable with multi switches in the past with 60/70 mtr cable runs with no problems.

Thurston?

Are all horizontal polarity channels not working? Measure the voltage at the end of the long cable, when 1 of the non-working channels is selected on the Sky box.

joeaverage

Thurston? wrote: »

Are all horizontal polarity channels not working? Measure the voltage at the end of the long cable, when 1 of the non-working channels is selected on the Sky box.

I'v gone thru most of the channels, only Sky Sports (1,2 & 3) and Challenge missing, showing no signal on the sky box, but work fine on my meter. I have also connected a new Sky box, same channels missing. I didn't check the voltage on the end of the long cable run, but I would assume its getting there if the meter can manage it.

Thurston?

So all 4 band/polarity blocks have at least some channels working on the Sky boxes?

joeaverage

Oh yea, all four bands have channels working, the only ones I can see missing are Sports and Challenge. But they are present on my meter, but not on the Sky box. I have ordered a roll of CT100 to see if it's a cable issue.

winston_1

joeaverage wrote: »

I have ordered a roll of CT100 to see if it's a cable issue.

Where from? CT100 has been obsolete for nearly a decade. You have either ordered old stock (unlikely) or a fake (most likely).

joeaverage

winston_1 wrote: »

Where from? CT100 has been obsolete for nearly a decade. You have either ordered old stock (unlikely) or a fake (most likely).

http://www.satworld.ie/black-ct100-satellite-cable-100m.html

byte

Ah, they just used CT100 as a generic term, though it's Antiference ANT100, which should be equally good, is CAI approved too.

winston_1

joeaverage wrote: »

http://www.satworld.ie/black-ct100-satellite-cable-100m.html

That is not CT100. CT100 was not foam filled.

joeaverage

Anyone got anything to add regrding the problem in question, I think we are straying off the point here. I think it's safe to say that the cable I ordered will more than address the the issue raised regarding cable quality raised earlier in this thread.

joeaverage

byte wrote: »

How long is the run? And what grade of cable is being used?

I'd be inclined to consider the amps/voltage coming up the cable being insufficent for the multiswitch to do the switching, whereas there may be a higher ampage on the meter, so things are fine.

A long cable run, depending on distance and grade would have a fall off due to resistance.

Top marks Byte, replaced the cake with CT100 or equivalent and problem sorted. Fitting IF distribution for 20yrs and regularly used 70mtr cable runs from the multi switch to the STB and never experienced this problem. Thanks again for your help.

byte

Glad you got sorted.

It is well possible that maybe the multiswitch is a bit intolerant of lower power from the Sky box, though the higher grade cable negates that loss of power.