Lost lots of channels with rooftop aerial - Want to try connecting Sky dish back up

1ntense

Novice Member
OK, so I live in a rented house. A month or 2 ago, ITV, ITV2, Channel 4, 4+1, dave, channel 5, e4 etc started going blocky. For a while, a bit of tweaking of the co-ax cable seemed to fix it after a while of mucking around with it but its gradually gotten worse.

Ive tried re tuning, both auto and manual which it wont let me do. Have tried re tuning with aerial unplugged to reset it. I had a booster box and tried that but again that didnt work as it takes the sky type cables and the aerial cable is just a normal co-ax. I could try a fancy co-ax cable from the box in the wall to my tv but doubt that would make much difference.

The landlady has basically said to the estate agent that the last tenants had Sky, not sure why that means that its not for her to fix as its her house, I dont see why I should pay to fix an aerial on a house that the landlady is supposed to maintain. It worked when we moved in and now has a problem. Anyway, so I have to try and get my tv working again myself.

Theres a Sky dish on the house with 2 cables running to the living room and one to the master bedroom.

If I was to buy a Sky box, would that enable me to get the channels that Ive lost? Would I need a card at all?

Just trying to find the cheapest way to fix it as money is tight atm with me being out of work.

Any ideas?
 

logiciel

Moderator
Get a satellite receiver and connect it to it one of the cables from the dish.
There's not much point in getting a specificallY Sky machine as you're not subscribing, but they do get the free channels, and used ones are very cheap, so that might be the best or easiest choice.
 

MartinPickering

Well-known Member
I could try a fancy co-ax cable from the box in the wall to my tv but doubt that would make much difference.
In my experience, the fly-lead between TV and wall socket is responsible for 50% of all Freeview terrestrial problems, followed closely by the wall socket, aerial drop-cable, connections, amplifier and PSU and (lastly) the aerial itself.

Fly-leads are very cheap and it's easy to make your own. Definitely worth a try before spending real money.
 

davedrizen

Novice Member
MartinPickering said:
In my experience, the fly-lead between TV and wall socket is responsible for 50% of all Freeview terrestrial problems, followed closely by the wall socket, aerial drop-cable, connections, amplifier and PSU and (lastly) the aerial itself.

Fly-leads are very cheap and it's easy to make your own. Definitely worth a try before spending real money.
Video Link: http://www.youtube.com/watch?v=KdBINEM3uS4
I have also found that connecting a second fly-lead in series with the first (daisy chain) can also improve things, as some time the actual length of lead can have funny effects on some channels.
 

MartinPickering

Well-known Member
If changing the length of a lead affects the signal, that's a sure sign of "standing waves" caused by a faulty lead or connector. Best to cure the problem, rather than try to cancel it out.
 

winston2010

Well-known Member
Sadly that video is incorrect. The brading of the coax should be taken round the outside of the claws not bunched up underneath and somehow twisted around. Such practice causes intermittent screen connections and ingress of interference.
 

logiciel

Moderator
"dozens of tiny cropped strands of copper wire lying around" is so true.:)
 

Rodders53

Distinguished Member
The fact that you can't spell "braiding"
Martin, criticising someone's spelling on an internet forum is normally considered extremely 'bad form'.

The BBC's Engineering Information Department promoted the alternative method of connecting braid to a Belling Lee in all their publications, as shown in How to wire a Belling-Lee connector This was possibly where Winston got his method from?

How To Attach / Wire Up Plugs, Wall Plates & Aerials thinks either will do.... as do I (having used both methods). I have seldom found the need to solder the pins (and it's a very risky business - even after trying to remove the plating from the pin - unless you do it regularly) but I would still agree that it is 'best practice' to do so.

Note: TV plugs are TOTALLY unsuitable for connecting an LNB feed for satellite TV. Because of the massive impedance mismatch, you are likely to lose some channels altogether or at least experience "poor reception".
I'm able to report that this is a myth ;) ... 25m of ordinary (albeit good quality) coax cable, screw-on F-plug one end unsoldered B-L plug and coax to F-plug adapter worked fine for me with my freesat recorder and quad lnb on a caravan touring holiday (OK I only needed to use it because trees by my pitch meant locating the dish further away than normal, but it worked - even in the rain!) I'd not recommend it though!

Back properly on topic:
I'd advise the poster to check through all the cables and connections for the aerial to see if there is a fault that can be fixed easily... The links in this post show alternative methods of how to make connections. Hopefully this will improve Freeview and avoid the need for a satellite solution.
 
Last edited:

MartinPickering

Well-known Member
Martin, criticising someone's spelling on an internet forum is normally considered extremely 'bad form'.
Yes, it's weird isn't it because, when I was at school, it was considered incredibly bad form (and a punishable offence) not to check spelling before submitting anything for public scrutiny. It was also considered to be extremely good form to help people communicate better. Strange how the world has changed to encourage illiteracy to the point where those who can communicate, and are willing to help, are considered pariahs. But this is part of the government policy to dumb-down the general population so that it's easier to control.

I would reaffirm that TV plugs are totally unsuitable for LNB feeds. The resultant impedance mismatch causes signal reflections that can potentially wipe out spot frequencies. This might go unnoticed if the frequencies affected are not carrying a wanted signal. However, a quick check with a 1GHz pulse generator and detector will show it happening. I carried out tests at university as long ago as 1970. The fact that someone "might get away with it" is not, in my opinion, a good reason for advocating it but it certainly does no harm to try it if you have a good reason for not using a simple 'F' plug.

In contrast, our proven method for fitting a TV plug for UHF signals has been shown to be no worse than any other method and somewhat simpler to perform. It's possible to avoid soldering by slightly kinking the copper wire and coating it with silicone grease to eliminate corrosion. However, I won't advocate this no-solder method because it's fiddly and less certain to be reliable. But, again, feel free to experiment.
 

logiciel

Moderator
While acknowledging forum "etiquette" I'll say that I welcome anyone pointing out my errors, and agree with the point that M P was making, that when anyone posts such errors that can be an indication that the poster could be more likely than others to be inaccurate too in the substance of his post.
 

winston2010

Well-known Member
Of course I know that Brading is a village in the east of the Isle of Wight and that there is a TV relay transmitter there of the same name. It was a typo not a spelling mistake.

I was not around in 1922 but I assume that method is the same as I use and as shown on that BBC link posted by Rodders53. To use the "dozens of tiny cropped strands of copper wire lying around" as a reason not to use this method is a pretty poor excuse for a professional such as yourself.

I worked for a large broadcasting organisation for many years and they had an RF distribution system with many channels using frequencies from 48 to 847MHz. (Getting equipment with VHF tuners was a pain but that is another story). When ever I got a call that there was patterning on some channels it was always on the band 1 channels caused by B/L plugs fitted your way. The braid contact was just not reliable enough. I suppose soldering the braid pigtail to the claws might fix it but why not do it the proper 1922 way. It was less of a problem on UHF channels but even so it did cause co channel interference from distant transmitters, especially in the top floors of the building.

Re the comments about not using B/L for satellite IF I quite agree, but remember BSB did this with their D Mac receivers and they seemed to work OK. That was not the only mistake BSB made however.
 

JamesE

Standard Member
There is no impedance mismatch using Belling Lee plugs. They are all 75 ohm connectors. They DO work for satellite connections. F plugs, which are the spawn of the Devil, were brought in for ease of connection (provided that the coax inner is a single strand - they cannot be used with true flexible cable!). and they do, in theory, introduce less loss for the microwave frequencies involved. However, if you want to use Belling Lee plugs then do so.
 

winston2010

Well-known Member
There is no impedance mismatch using Belling Lee plugs. They are all 75 ohm connectors. They DO work for satellite connections. F plugs, which are the spawn of the Devil, were brought in for ease of connection (provided that the coax inner is a single strand - they cannot be used with true flexible cable!). and they do, in theory, introduce less loss for the microwave frequencies involved. However, if you want to use Belling Lee plugs then do so.
All connectors have a slight impedance mismatch 'cos we don't live in a perfect world. But F, BNC, TNC, N type etc are all pretty good at minimising it. The humble B/L however was not designed for UHF or sat IF frequencies and gives a very poor match at 75ohms. It can work for satellite and can be easily dislodged while dusting with a possibility of shorting the LNB feed as this happens, another reason for not using it.
 

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