Strange goings on with 4k freesat box

chris TR6

Novice Member
Hi everyone, new on hear but trying to see if anyone/other installers have had the following issues:

I have recently installed a system into a barn, 60cm dish with a hybrid LNB, this feeds down into what might be loosely termed a plant room, the feed from the dish enters a wideband splitter, one feed goes off upstairs to a 1TB freesat receiver, the other feed goes literally 300mm into a second 1Tb freesat RX, the hdmi output from the rx goes into a triax modulator, one output of this, hdmi, goes to a tv some 2m away, the rf out from the triax goes to a standard slx distribution amplifier, hope you are all still with me !
Ok, so the rx upstairs is working perfectly, hasnt missed a beat which has amazed me considering the problems i have had with a product i feel is not yet fit for purpose, however the freesat rx in the plant room works beautifully but regularly has audio distortion, the type where the speaker cone is scratching the coil, switching off the box for few seconds cures this, friday the customer said switched off in the evening &in the morning presented with nothing on this plant room box either via hdmi or D/A,yet upstairs working fine, son , practical, swapped the upstairs boxes round, box upstairs worked but again no signal downstairs, swapped the splitter outputs , no different, so despite the upstairs box working perfectly off the same LNB no signal on the other. Well, its gotten me perplexed, i am beginning to wonder if any of the other gear in there is causing rfi, particularly switched mode psu, have alarm box, dyson psu, freesat psu, d/a etc, would love to hear if anyone has had same issues, have replaced box anyway...no different ! Chris
 
Last edited:

Rodders53

Distinguished Member
Remove splitter and test each RX in turn direct connected. Does the plant room one work direct?

Check signal strength and quality on a variety of channels on each box, when working, it may show up an issue.

Splitters lose between 4.2 and 5.5 dB at the higher frequencies... so too much signal (overload) would seem unlikely. But it may be the issue?

Try alternative leads. Ensure they are all-copper type WF100 or equivalent. Add a length equivalent to the other run to the local receiver? (Cable loses relatively little over normal lengths - if WF100, at least ;) ).

Possible interference:
Relocate the plant room box a few metres away from other items - sometimes boxes aren't as well screened as we might like?
Get an alternative mains feed in temporarily (different ring main) to feed the box, to see if it's on that mains socket/circuit.
Feed only the TV losing the hdmi-connections to modulator (and power it off).
hdmi leads can radiate RF and not all are well screened so try alternatives of those too, perhaps.
Power off any suspect other devices to see if that helps?

Feed one 4k pvr from the legacy outputs of the lnb - OK you're restricted to two tuners then but it may prove something?

Distortion issue: on both hdmi connected TV and the RF fed ones, identical or??? Can it be replicated from a recording made of the channel affected?

As you are a trained pro - use your satellite meter to check the levels at both locations, and/or reach out to the pro community (CAI, RDI etc.,.) for advice that may help your customer?
 

chris TR6

Novice Member
Thanks for your very prompt response, i have had my meter on both&there is little difference in signal presented to the boxes, the upstairs one which works fine is a little lower but then there is another 18m of cable. Interestingly the customer was using their sky Q box for a month until having to return, that was much better but still had the audio issues occasionally which again required the box to be turned on/off to cure which leads me to believe it is a corruption issue. I will see if i can try the receiver in a metal tin to act as a faraday cage temporarily, the rx is alongside the main house consumer unit, i must see if there is a proprietry mains noise filter. I didnt realise hdmi cables can radiate, to my knowledge it was a decent cable we installed but you never know, the hdmi from the rx to the modulator was the one supplied by sky, have since changed this will see
 

chris TR6

Novice Member
Remove splitter and test each RX in turn direct connected. Does the plant room one work direct?

Check signal strength and quality on a variety of channels on each box, when working, it may show up an issue.

Splitters lose between 4.2 and 5.5 dB at the higher frequencies... so too much signal (overload) would seem unlikely. But it may be the issue?

Try alternative leads. Ensure they are all-copper type WF100 or equivalent. Add a length equivalent to the other run to the local receiver? (Cable loses relatively little over normal lengths - if WF100, at least ;) ).

Possible interference:
Relocate the plant room box a few metres away from other items - sometimes boxes aren't as well screened as we might like?
Get an alternative mains feed in temporarily (different ring main) to feed the box, to see if it's on that mains socket/circuit.
Feed only the TV losing the hdmi-connections to modulator (and power it off).
hdmi leads can radiate RF and not all are well screened so try alternatives of those too, perhaps.
Power off any suspect other devices to see if that helps?

Feed one 4k pvr from the legacy outputs of the lnb - OK you're restricted to two tuners then but it may prove something?

Distortion issue: on both hdmi connected TV and the RF fed ones, identical or??? Can it be replicated from a recording made of the channel affected?

As you are a trained pro - use your satellite meter to check the levels at both locations, and/or reach out to the pro community (CAI, RDI etc.,.) for advice that may help your customer?
Actually out of interest what would you consider too much signal to cause overload?
 

winston2010

Well-known Member
I have recently installed a system into a barn, 60cm dish with a hybrid LNB, this feeds down into what might be loosely termed a plant room, the feed from the dish enters a wideband splitter, one feed goes off upstairs to a 1TB freesat receiver, the other feed goes literally 300mm into a second 1Tb freesat
Ypu cannot split satellite signals like that.
 

chris TR6

Novice Member
well i respect your opinion, however i beg to differ, please if you make a comment, explain why you think not
 

chris TR6

Novice Member
not sure you understand the system design, as stated the pictures are fantastic, remote control everywhere, HD etc etc, why do you say that i am always willing to learn ?
 

Rodders53

Distinguished Member
Actually out of interest what would you consider too much signal to cause overload?
Dunno. I'm not a pro satellite installer.
What do you measure at the two locations (at both the lower and higher frequencies) and with/without the splitter?

Have you got the box working in plant room with no splitter?

Have you tried replicating the 18 metre extra cable length on the plant room box inatall?

Google found me this semi-relevant info: Split a wideband lnb signal

Triax do passive splitters specifically designed for this job in their TWS range: TWS2 Wideband Splitter H/V

New generation Freesat STB - Arris sort of means Winston's had a brain fog ;)
 

The latest video from AVForums

AVForums Movies Podcast: We review Dune and ask which is the best decade for horror movies?
Subscribe to our YouTube channel
Support AVForums with Patreon

Top Bottom