Replacing damaged CCTV rg59+2 cable in garden

i need to replace 3 meters or so damaged RG59 +2 cable. It's outside in the garden about halfway on a 45 mtr run from HDI camera to DVR. What's the best way to do it, bearing in mind weatherproofing is essential! Maplins suggested two joint boxes .... But at ground level I'm not sure! Also, is there a danger of losing signal/picture quality?

Hd sdi ? Would probably say replace all the cable as they don't like joints

Probably best way would be a BNC plug (soldered or crimped) on ends of each existing cables, and BNC plugs on each end of new section. Use a BNC connector to join the two plugs at each join location.

Place the joins in something similar to these ( http://www.screwfix.com/p/prysmian-puj2cc-resin-joint-kit-2-5mm-4-core-max/61439 ) and fill with the supplied resin.

Or two of these - http://www.coax-connectors.com/products/connectors/miscellaneous/76-570-q6-ai.aspx

Cost unknown!!

That is not a big deal to try and see final quality of signal. In theory your HD-SDi signal already lost -12db on 50m distance of RG-59. To do 2 joints use F- connectors. Will require 2 - FF and 4 - F plugs. Benefits of using these connectors are - much more reliable when BNC plugs, not required crimping tool, low signal cut just 0.5db per joint and low cost. Again in theory after that repair your signal will be -13db what is very satisfactory to keep SDi picture clear. To waterproof connections use Self Amalgamating rubber tape. Wrap it tightly round a joint and it will make solid waterproof isolation what you can leave even underground.

Signal reduction will not affect the quality of the picture until the signal level is reduced down to the noise level of the system

Quality is reduced by distortion of the signal due to joints / cable joins with mis-matched impedances causing reflections of some of the signal backwards towards the source. This reflected signal mixes with the signal from the source and distorts it slightly.

With care RG59 can be joined by soldering the centre conductor, replacing the insulation around it and then layering the screens on top of each other and soldering a few strands across the joint. Then protect with adhesive backed heat shrink sleeving.