Humax Freeview - Interference from traffic

[Jamp]

I have a Humax F2-Fox freeview box but am struggling to get a trouble free picture on all channels.

I live in a flat with shared loft aerial. The aerial is very big but mounted so it has to get signals through a brick wall and the roof tiles, not ideal. Then there's some sort of amplifier which splits the signal into 4, then around 20m of brown coax cable to my wall socket. This gives mediocre analogue signals, so I was suprised the freeview box managed to get anything at all without me needing a new aerial. However, I'm still not happy

I had several cheapo Wilko's coax leads to go from the wall to the tv or freeview box, these gave varying results according to the route the cable took, staying away from power cables giving much better (but never good) results with analogue or digital. This led me to believe I needed a better shielded cable, so I went for a Bandridge 1.5m cable thinking this would do the trick.

It gives a big improvement, I now get numerous extra channels, some of them faultlessly (although I still only get up to 50% signal strength, but high quality on most BBC channels, plus a few others). I'm still struggling with a few of the channels, ITV channels, C4, and a few others give poor performance.

It is made much worse if a big vehicle drives along the road outside (approx 10m across from my building but my flat is 2nd floor), or if a car is parking up outside my flat, in these cases the ITV channels become unwatchable and the usually better (in terms of signal I get) channels get iffy. I hadn't noticed the traffic problem with the cheap cables, only a petrol strimmer being used outside messed up the signal completely.

Something else to note about the new cable is that the radio channels are now poor. The box's primary use is for 6music, this has now gone very patchy, although more radio channels are now available to select
.
What's the next step to take to get all my channels working reliably? Would a Profigold cable show a further improvement, and possibly solve the traffic problem? Other options? I'd rather not spend on a new aerial install seen as I seem to close to getting what I want with this one.

Many thanks in advance for any advice.

Cheers,

Ben

 

[Archie Fax]

Originally posted by Jamp

.
What's the next step to take to get all my channels working reliably? Ben

Unfortunately, a completely new aerial installation is required here IMO. Be sure that satellite grade double sheilded coax cable is used. Avoild distribution amps if possible- so that there is nothing to potentially boost the noise that is causing the problem.

I suffer the same traffic break up myself caused by a digital signal that is too weak. - Nothing I can do about it -.

 

[idhutt]

Maplin do a TVI RF Filter (QT25C) for a tenner - made a big difference when the kids outside use to race their unsuppressed scooters up the road. A second one also completely cut out interference from a nearby low voltage lighting transformer that was causing interference on the RF output to a second room.

Apparently it attenuates the signal slightly and can't be used with an amplified signal - but this didn't cause me a problem.

-Ian

 

[Jamp]

Thanks for the replies. Not sounding good is it.

I think I'll try a better cable from wall socket to the box first though, seen as going from the cheap one to the bandridge one made such a difference (including having a negative effect on the 6music signal), wouldn't that indicate that a 'perfect' cable might pretty much solve my problems?

I suspect the aerial installation is actually quite good, it's mounted badly but that is due to the constraints of it being in the communal bit of a the loft, but hopefully the cable from aerial to my wall socket is pretty good.

A better cable from wall to box can't do any harm anyway can it. What's best to go for do you think? 0.75m Profigold ones are sold on eBay for around £10 all in, are there better options though?

Cheers,

Ben

 

[simon123]

yea just ring the local aerial rigger and ask can he make you a lead up with CAI marked cable (ct100,h109f,wf100,etc) and crimped plugs

i sell my fly leads 2m for £3

but this is not mainly your problem
incorrect aerial you need wideband
low aerial signal in loft
unscreaned amp
unscreaned cable
unscreaned outlet socket in flat

the problem you are getting with cars and power tools is impulse noise and only screaning and crimping connections with rectify this

also if you live on a main road,or you are pointing your aerial over nearby water (sea,river)to the local transmiter this can effect signal to sort this out the aerial should point upwards by about 5 degrees

 

[Fernsehman]

All of the above replies are right. And if you want the biggest improvement for least cost/effort, replace that 20metres of brown coax with proper double-shielded satellite cable and DON'T use a wall plate. Plug the cable direct into the Humax. Most of the interference is likely to be picked up by that brown unshielded coax because it's acting as a vertical aerial wire. If there's a choice, keep the new coax as far from the road as possible.

Other than that, according to The Freeview Bible, you can try a "Log Periodic" aerial mounted as far from the road as possible (preferably outside).

 

[simon123]

agree