Coax cabling problem - Analogue but no Digital

Forums › Freeview (DVB-T/DVB-S) › Coax cabling problem - Analogue but no Digital

ryall

5 posts

Wannabe Geek

#45401 2-Nov-2009 09:05

I decided to replace the coax cabling from my antenna since the old one was looking pretty ratty. However now that's done I can't get a digital signal at all. Analogue TV works OK (it was never that great), and the signal is affected by moving the antenna, so there must be some kind of connection there.

One thing that semi-threw me is that the new coax cable has two layers of braided wire (is this double shielded coax?). I just presumed the outer layer was extra shielding and trimmed it off, while using the inner layer for the connection. I'm getting the feeling that this was a dumb move, but there doesn't seem to be enough room in the connectors to have both layers in there.

Does anyone have any suggestions that might help?

Deev8

481 posts

Ultimate Geek
+1 received by user: 5

#269218 2-Nov-2009 11:16

ryall: One thing that semi-threw me is that the new coax cable has two layers of braided wire (is this double shielded coax?). I just presumed the outer layer was extra shielding and trimmed it off, while using the inner layer for the connection. I'm getting the feeling that this was a dumb move, but there doesn't seem to be enough room in the connectors to have both layers in there.

From the description you have Quad Shield RG6 cable. Firstly you need to ensure that you have appropriate connectors for the quad shield cable. Then to prepare the cable you strip back the outer jacket, fold the outer braid back over the jacket, remove the first layer of foil, and fold the inner braid back over the jacket. Then slide on the connector and crimp it.

Carefully check that none of the braiding is wrapped around the cable's central solid conductor - it often happens when using a rotary cable stripper, and it can be difficult to see individual strands of the braid. I use a magnifying glass to check.

Dingbatt

6804 posts

Uber Geek
+1 received by user: 3694

Lifetime subscriber

#269222 2-Nov-2009 11:23

Sorry to ask the obvious, but have you had a close look to make sure there are no stray strands from the braided wire touching the core or its connectors?

“We’ve arranged a society based on science and technology, in which nobody understands anything about science technology. Carl Sagan 1996

Jaxson

8172 posts

Uber Geek
+1 received by user: 1332

Trusted

#269233 2-Nov-2009 11:41

Dingbatt: Sorry to ask the obvious, but have you had a close look to make sure there are no stray strands from the braided wire touching the core or its connectors?

Agreed. Given the trouble you've had with the fidly coax, I'd start there.

ryall

5 posts

Wannabe Geek

#269252 2-Nov-2009 13:08

Thanks for the input guys. I'll redo the connections and make sure that there's nothing touching the core.

Deev8: So both the braided layers should be touching each other when they're crimped?

Deev8

481 posts

Ultimate Geek
+1 received by user: 5

#269298 2-Nov-2009 15:50

ryall: Deev8: So both the braided layers should be touching each other when they're crimped?

That's right.

You might find this Youtube video useful (regardless of the "this is the best connector on the market" advertising hype): How to Install RG6 Quadshield Waterproof Compression and Hex Connectors

sbiddle

30853 posts

Uber Geek
+1 received by user: 9996

Retired Mod

Trusted

Biddle Corp

Lifetime subscriber

#269335 2-Nov-2009 17:33

The best option for connectors is to use F compression or radial crimps and then a F -> belling lee adapter. This of course if a pain if you don't have the right tools but is the best way to get the job done right the first time!

AliExpress

Shop now on AliExpress (affiliate link).

ryall

5 posts

Wannabe Geek

#271435 9-Nov-2009 20:59

Managed to get back on the roof in the weekend. I'm not sure if this is a red herring or smoking gun, but there was some foil touching the inner core. Re-did the whole connector following the advice from you guys (thanks heaps for the youtube link) and now digital is coming through crystal clear.

Big thanks to you guys for all the help :)

Deev8

481 posts

Ultimate Geek
+1 received by user: 5

#271554 10-Nov-2009 10:08

ryall: I'm not sure if this is a red herring or smoking gun, but there was some foil touching the inner core.

That wasn't a red herring - it was a significant problem.

ryall

5 posts

Wannabe Geek

#271561 10-Nov-2009 10:21

Good to know. I wasn't sure if the foil was conductive or acting as an insulator.