No aerial, but I have digital channels. How?

David Chapman

Active Member
The only input into the distribution amp in the loft is an uplink from the lounge which has no device supplying it, yet I can tune in digital channels.

As soon as I connect my Humax Foxsat HDR to the uplink via Triax Tri-link RF out the digital channels are no longer available, only the analogue Humax feed.

Disconnecting the Tri-link RF out immediately restores the digital channels.

How can I receive digital channels with no aerial?
Why does the Humax RF signal knock out the digital channels?

Thanks for any info.
 

EndlessWaves

Distinguished Member
It's not uncommon with terrestrial signals in areas with high signal strength. It's the aerial cable acting as a basic antenna and picking up sufficient amount of signal to work.

You don't say what your first tuner is, but your second one is a satellite tuner so are you saying you're seeing this on satellite signals?
 

David Chapman

Active Member
Not sure what you mean by "first tuner"?
With the Humax disconnected I'm connecting to LG 55B8 and Sony KDL-32WE613 (in different rooms) and scanning for digital channels.

Digital channels on both sets are crystal clear.

As an aside, the Humax via Tri-Link RF feed is clear on the Sony but fuzzy on the B8. The B8 supposedly has an analogue tuner but all I can find is aerial "channel tuning" so I manually tuned to the Triax's channel 32, as currently set via its little dials.

I have a recently acquired Humax HDR-1100S to replace the old Foxsat and plan to buy a HDMI to coax modulator (Triax 103) but thought I'd test the route with the old system first. Still a bit worried about the B8 picture with the new set up.
 

Rodders53

Distinguished Member
The tri-link is a radio-frequency modulator and that will be very high level cf the direct pickup from the cables. That will cause receiver tuner front end electronics to reduce their gain to get that strong signal to the correct level. So the terrestrial signals are below the receivable level.
Probably.


Solution: Fit an aerial (maybe in the loft) and - if necessary - another cable down to the tri-link location to feed that aerial signal into the tri-link input so that both aerial and tri-link signals are fed through the D-A on to all the other outlets in the home.


Location is needed to advise more accurately on aerial selection etc.,.


The different sat PVR will make no difference nor will the different modulator. An aerial is required.
 

David Chapman

Active Member
I don't think I need an aerial as normally we never watch terrestrial TV?
We're only using it now as broadband doesn't get switched on until this Friday. Once that's in, we'll go back to watching in two ways:

1/ App TV via Wifi to four TVs (Kitchen/breakfast room; Lounge; Master bed; 2nd bed).

2/ Satellite TV to all rooms via Humax HDR-1100S > Triax MOD103T modulator > Labgear HDU681 distribution amp > Coax wall plates > TVs.

So this question was really a curiosity as to why, during this short period to Friday, we get digital channels. We won't need them from then on.

But my concern now is fitting the MOD103T and still getting a poor picture on the B8. I'm going to phone LG technical in a bit...

Thanks for you help in explaining that it's the cables acting as an aerial. I did think back to the old days... wire coat hanger etc.
 

Rodders53

Distinguished Member
The 103 is a DVB-T modulator and pics from it will be perfect or nothing or breakup if on the digital cliff edge for signal levels.

A loft aerial would cost peanuts cf that modulator box and if wanted the two could be 'combined' together so best of both worlds (and ability to have Channel 4 in HD for live viewing on Freeview).

TVs usually have signal metering built in - but not sure about analogue tuners now... so long since we've had analogue TV to watch - so maybe use that on the problem TV?

Poor analogue pics is usually down to lack of signal... and that may just be a dodgy connection on the plugs/cables/sockets feeding that problem set? Check and fettle them?

Put the Custom Firmware on the Foxsat-HDR and, after installing nowsters patch to stop HD encryption, you can stream the recordings to other TVs via an ethernet cable to a router. Also can allow C4 HD (non-freesat) to be viewed/recorded in freesat mode (a bit fiddly to do, though).
The 1100S can't do any of that.

Two more cables from the LNB to a second PVR would allow both fresat PVRs to be used? Extra cables from an octo lnb could allow any TV's with sat tuners to be used as well?
 

David Chapman

Active Member
@Rodders53 - Just a few notes on your post:

The 103 is a DVB-T modulator and pics from it will be perfect or nothing or breakup if on the digital cliff edge for signal levels.

- LG suggested taking the Sony to the LG's location to see if it still gives a clear picture. If the Sony does, it's not the coax to that wall plate, so call them back. Just holding off buying the DVB-T modulator until I'm happy the network it's joining is OK.


A loft aerial would cost peanuts cf that modulator box and if wanted the two could be 'combined' together so best of both worlds (and ability to have Channel 4 in HD for live viewing on Freeview).

- Does "cf" mean "coming from?" If so, surely an aerial would plug into the Triax 103 "RF in" or the Labgear distribution amp's aerial in, not "from" the modulator?


TVs usually have signal metering built in - but not sure about analogue tuners now... so long since we've had analogue TV to watch - so maybe use that on the problem TV?

- The B8 has an analogue tuner, but unlike the Sony where digital and analogue tuning are listed separately, it just has "aerial tuning."


Poor analogue pics is usually down to lack of signal... and that may just be a dodgy connection on the plugs/cables/sockets feeding that problem set? Check and fettle them?

- Will do.


Put the Custom Firmware on the Foxsat-HDR and, after installing nowsters patch to stop HD encryption, you can stream the recordings to other TVs via an ethernet cable to a router. Also can allow C4 HD (non-freesat) to be viewed/recorded in freesat mode (a bit fiddly to do, though).
The 1100S can't do any of that.

- Not keen on surface routing an ethernet cable to the router. Not into anything more fiddly, this is fiddly enough for me!


Two more cables from the LNB to a second PVR would allow both fresat PVRs to be used? Extra cables from an octo lnb could allow any TV's with sat tuners to be used as well?

- I've fitted extra cables from LNB before, but with two PVRs, how would I feed their 2 x HDMI into the Triax 103T? Some kind of combiner?
I've read LG inbuilt sat tuners don't have a satisfactory EPG and so have never tried. I'd also have to route these extra (up to) four cables around the exterior walls - not necessary in any case.
 

Rodders53

Distinguished Member
cf : Cf - Wikipedia. "compared to" in the use I gave it.
e.g under £17 for a log periodic TV aerial from here which might well be ok in your loft (very location wrt transmitter and often roofing materials dependent). Compact Log Periodic TV Aerial 28 Element compared to the £140+ for a DVB-T HD capable modulator.

Swapping TV sets to the 'other aerial socket' is a useful tool: it proves a cable is OK (or not) or that one TV is more sensitive than the other. Or maybe not connected to the amplifier. Or...
Check that the distribution amplifier really works: direct-connect the uplink input cable to the problem room's output cable?

TV satellite EPG - suck it and see? Feed the TV(s) with one of the two sat feeds to try them out, before committing to a cable run/install?
Many TVs, though, aren't the freesat epg so often a dogs dinner needing a lot of sorting / favourites and a need for occasional manual retuning and re-sorting.

Ethernet cables can be routed inconspicuously with care. Even externally in conduit or using UV stable outdoor cable (look like telephone wires). Alternatives are Powerline mains (variable results depending on mains wiring / mains consumer unit circuit layout etc.,.). Or perhaps mesh wifi units with ethernet socket connections.

I wasn't expecting you to have both PVRs being fed to modulators... But if you wish you can cascade two 103T or similar modulators. There are also twin hdmi input versions on sale at not insignificant cost.
 

David Chapman

Active Member
I want to run a Humax recorder so I can pause and rewind live TV. Had the old one for donkeys years but only 500GB and keeps switching off, hence the 1TB HDR-1100S to replace it.
 

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