Coaxial cable and TV Plug connection

[Mina131]

Hi all. Any help would be greatly appreciated....

I foolishly played around with various tv connections, swapping leads etc. Anyway I think I caused problems to the coaxial cable/connector (just in case I am using the wrong terminology I mean the lead which connects the aerial to my tv). I watched a couple of "how to" videos and re-did the connections and the signal changed from "poor" to "fair but my tv upstairs (which is on a splitter) is working great so I don't get what the problem could be. The one thing I didn't do was solder the end of the wire, would this make a difference? Also could it be anything else I am missing?

This has been doing my head in for ages and so if anyone can help I really would appreciate it! Also I really don't know that much about these things so feel free to talk in simple language and patronise me!

Many thanks

 

[wotan]

when making a co-axial cable joint to a tv plug, it's vital that the center conductor insulation is cut back to the right length, it does not need to be soldered just put a slight kink in the bare copper.
make absolutely sure there is not one whisker, of the outer braid touching the central conductor, the outer braid should be rolled back and be held captive by the compressible ferrule before screwing the end cap on the plug.

Hope this makes sense.

Wotan

 

[ban-all-sheds]

I foolishly played around with various tv connections, swapping leads etc.

Why?

Were you having a problem beforehand, which you were trying to fix or narrow down?

 

[Mina131]

Thanks Wotan that is very helpful. I really appreciate it. Just a couple of questions, if that's ok. When you say it's essential that the centre conductor is cut back am I right in thinking that the centre copper wire shouldn't protude from the plug? It should be the same length as the plug? If that makes sense? Then the soldering would make sure it stays in contact? I did double check the copper braid but thanks for mentioning that one. Also does it make any difference having a lot of copper braid? It's wrapped round the lead quite a few times and wondered if I cut off a bit whether that would improve anything?

Ban, I know this may make me seem like an 80s girl but I was connecting my old video to the tv. I also have a dvd recorder and sky box so was taking some messing around and I thought I may have dislodged something as the aerial connector didn't seem that secure to me although didn't think anything about it until the picture quality was getting worse. Absolutely no problems before I connected the video so I ended up disconnecting it but with no improvement. Checked the aerial connector and then got no picture! So I played around with it a couple of times and it went from no picture to poor to fair. Kicking myself now though!

 

[electronicsuk]

Thanks Wotan that is very helpful. I really appreciate it. Just a couple of questions, if that's ok. When you say it's essential that the centre conductor is cut back am I right in thinking that the centre copper wire shouldn't protude from the plug?

No. It's usually easiest to cut it flush with the end of the plug if the centre pin is hollow, as you're pretty much guaranteed to have inserted it far enough to make good contact.

Then the soldering would make sure it stays in contact?

You can solder it if you want, but there shouldn't be any need if you put a small kink in the copper as advised. Even if you didn't take this step, it's still unlikely that you'd have any problems.

Also does it make any difference having a lot of copper braid? It's wrapped round the lead quite a few times and wondered if I cut off a bit whether that would improve anything?

No, it wont make any difference, other than perhaps making things a little neater.

Checked the aerial connector and then got no picture! So I played around with it a couple of times and it went from no picture to poor to fair. Kicking myself now though!

Are you sure everything is connected back as it was originally? If the signal is looping through anything then it could kill the signal, so I'd suggest connecting the aerial lead directly to the TV to see what sort of a picture you get. It's also not unheard of, if the TV is getting on a bit, for there to be a dry joint or other bad connection on the antenna socket inside the TV itself. I've seen this a couple of times, and wiggling the plug around in the socket just right will fix it temporarily.

 

[ban-all-sheds]

Also, check the contacts on the coax sockets and female connectors - they can sometimes get a bit splayed, and it can be worthwhile gently nipping the inner contact with a pair of fine-nosed pliers and squeezing the outer ones together. If the latter is in several sections you might find that levering them inwards a tad with a small screwdriver blade works.

Basically you should be able to feel resistance as you insert the plugs, if you don't then something is wrong.

You talk about soldering - I don't know what sort of iron you have, or how good you are, but if you do solder you'll need to work fast, and use a heat sink, as the inserts in plugs melt very easily. If you're concerned about the contact between the inner core of the cable and the centre pin of the plug then a kink as wotan said is all you need, but if you're determined to solder then just tinning the cable core might make it big enough to be a snug fit.

 

[Mina131]

Thanks Electronics. I'm pretty sure it's the cable or the connector as the tv is only about 3 years old and is a decent Samsung one. Whilst the cable and connector look a bit hammered!

I did connect the lead directly to the tv. And it was then, after redoing the connector I got signal information saying that I had "poor" quality and then saying I had "fair" quality (whilst upstairs was fine all the time and that tv is about 10 years old!). So assumed the problem was the belling or the cable.

if you put a small kink in the copper

Sorry about this but I just don't understand this bit. If I cut the copper wire to make it flush with the hollow pin where would the kink or bend be?

Thanks Ban, I'll try that tonight. Wow do I know how to have a good time....

Thanks so much for all this and sorry about the stupid and basic questions!

 

[ban-all-sheds]

Sorry about this but I just don't understand this bit. If I cut the copper wire to make it flush with the hollow pin where would the kink or bend be?

In the bit inside the hollow pin, so that you're sure to get it actually touching the pin at some point.

 

[Mina131]

Thanks all. Really useful

 

[Steve]

only about 3 years old and is a decent Samsung one.

Means nothing. I've had the pleasure of tuning in 3 LCD/plasma screens in this house. And couldn't get any of them to pick up as good an analogue signal as the CRTs they replaced. The lack of any fine tune function means on most sets now you're relying on the TV's autotune program to sort everything out for you, but most times these are sh*t and you have to go "around the houses" to tune them in right, but even the best signal isnt as good as before. Thank goodness for digikil.

 

[ban-all-sheds]

The problem with digital is that where with problems with an analogue signal you might get brief degradation of the picture and sound, but still maintain continuity of picture and sound, with digital it just stops dead and you completely lose it.

A little bit of snow and noise is preferable to SFA.

 

[Monkeh]

More often you just get missing blocks and sound glitches. Quite preferable to a severe lack of channels and image quality!

 

[ban-all-sheds]

Lack of channels?

How many can you watch at any one time?

 

[Monkeh]

Lack of channels?

How many can you watch at any one time?

I can presently record any number of channels on up to three multiplexes at once. Watch.. I've been known to watch two channels at once.