Combiner and Saorview

cord

Using Satellite VHF/UHF combiner to combine Sat and boosted outside aerial to single coax. Second combiner to split coax at TV. Sat working OK but only analogue TV no DTV (No Signal). Eliminate combiner at TV and use single coax to antenna input on TV and I have DTV. Have tried the RF in and out on the sat receiver to boost signal, but no good! Please help!!!

The Cush

Can you post a pic of the combiner at the TV end?

cord

Something like this

http://www.satellite.ie/acatalog/Satellite_UHF_combiner.html#asatufhcom

Branded EW3......not sure how to attach files or pic's

Thanks

Ronnie Raygun

If you remove the satellite connection from the combiner (or power off the sat. receiver), do you then receive Saorview through the UHF output?

Edit: Seen your thread here from a few years back. Are you still using these same combiners? Mightn't be a bad idea to try new ones if that's the case ...

cord

Thank for that Ronnie, just checked my old post and yes, same combiners! It was an old crt tv for kids, usually used for dvd's and sat. Now a new plasma watched by the adults and only one coax! Will the new combiners iron out the problems? Tried unplugging the digibox power, but no change.

update: yes signal back when I unplug digibox....it's on to Tony for new combiners!

Ronnie Raygun

cord wrote: »

Will the new combiners iron out the problems?

Only one way to find out. Worth a shot, since these ones seem to have "previous".

cord

Thanks Ronnie, yes I guess I need two new combiners.

Fuzzy Clam

I might be wrong here, but wouldn't any combiner on a boosted aerial prevent the booster working?
The combiner allows DC to pass to the LNB but not to the terrestial aerial. So how can a combiner work in this instance?

Ronnie Raygun

Depends how the amp is powered or where its psu is in the setup; wasn't specified by OP.

cord

To answer.. the booster is placed in the attic just after aerial, it is used to boost signal to other tv's, but I guess not the one with the combiners!

Just to update...was in touch with Tony from Sat's.ie and he advises that it's probably the digibox outputting RF on the dish input. Not common but can happen.....so UPC is looking good!!

Compton

Does it have a powerpass?

cord

Combiners?....yes the combiners have a power pass on the high freq, side

Ronnie Raygun

Try new combiners, these ones are probably just passing lnb "noise" to the terrestrial side & interfering with signals on these frequencies.

Ignore comments about power pass.

Peter Rhea

cord wrote: »

....so UPC is looking good!!

That doesn't make much sense.

You could at least try replacing the cheapest components in the system (the combiners ) before signing up for pay tv. Or just run a separate cable for terrestrial signals.

watty

cord wrote: »

Using Satellite VHF/UHF combiner to combine Sat and boosted outside aerial to single coax. Second combiner to split coax at TV. Sat working OK but only analogue TV no DTV (No Signal). Eliminate combiner at TV and use single coax to antenna input on TV and I have DTV. Have tried the RF in and out on the sat receiver to boost signal, but no good! Please help!!!

It won't work.

You need TV/Sat adaptors at each end and they MUST block DC volts on the TV connection as the Satellite LNB is powered from set-box and uses 13V approx on Vertical and 19V approx on Horizontal channels.

So you need to move the Aerial power unit to between the Aerial and the first 950MHz splitter/combiner that takes the aerial and LNBF from outside.

cord

@ peter...UPC said in jest . Can't drop an extra coax cable in, in this situation.

@ watty...the combiners that I'm using are as per the link I gave earlier. Which allow power to pass on the higher Freq' side (Red)LNB and blocks it on the lower Freq' side (Black)TV....tell me if I am wrong...As I have supplied other TV's in the house with boosted aerial signal, I have taken one of the boosted supplies and put it through the first combiner with a feed from the LNB.

watty

You can ONLY power the LNB via the coax. The Combiners as you say only pass power on the Satellite side and the LNB must only be powered

Set-box to Dish uses the High Frequency or Sat ports:
Set-box--coax -->combiner

---

coax run

---

combiner<--coax--LNBF

The aerial (the same combiners as above but the TV ports)
TV --coax-->combiner

---

coax run

---

combiner<--coax--PSU--coax-- aerial

The power unit for the "booster" aka amplified aerial MUST feed the aerial directly, then the coax that would have connected the PSU to back of TV goes to the TV port on the combiner.

The TV ports do 5MHz to 900MHz and MUST block DC power and 22kHz.
The Sat ports ( aka "High frequency ports") do 950MHz to 2100MHz and pass both DC power and 22kHz from the setbox (ONLY) to the LNB.

The "com" port on the combiners connect to each other via the downlead.

No other configuration is possible with an amplified (boosted) Aerial that needs power.

If the Aerial amplifier (booster) is 12V powered then the LNBF feed voltage in H mode could destroy it (17V to 20V, normally 18V or 19V) if you somehow connected DC from the cable to the aerial.

If this is the wiring you have then the combiners are faulty.

cord

My layout is a you described. Except, I need to get this right, the aerial is not boosted like a large UK aerial? It's an Irish UHF? that I have bosted with a labgear booster. Any ideas on how to solve the interference problem, so I don't have to turn off the power to the digibox to watch RTE (DTV)?

watty

If you have wired it as I described and you have proper Sat/TV splitters it works. The kind of aerial and amplifier is not relevant.

Don't route TV aerial signal via the RF in and Out1, Out2 of the Sky Digibox as the Sky Modulator uses up 4 channels and is noisy.

Peter Rhea

cord wrote: »

My layout is a you described. Except, I need to get this right, the aerial is not boosted like a large UK aerial? It's an Irish UHF? that I have bosted with a labgear booster. Any ideas on how to solve the interference problem, so I don't have to turn off the power to the digibox to watch RTE (DTV)?

Seems like you have one output from a mains-powered distribution amp feeding into the tv side of the combiner. Have to agree with 'Ronnie Raygun' that new combiners is the way to go, since these ones don't seem to have ever worked right.