Car radio antenna cable connections

pdc1, Sep 10, 10:41pm
Hi, just fitting a new antenna to a car. It's an electric up and down one, that comes with a short cord and plug.
The one on the car if different brand of antenna and I'm modifying new one to fit the vehicle. The cable disappears into the car under panels, seats, carpet, consul etc. Would be easy to just chop the existing cable and the new cable and join together appropriately with solder and heat shrink.
The radio is a digital type. Am I going to mess up reception by doing this, or does the cable have to be a certain length, and the joins done in a certain way! Cheers

ceebee2, Sep 10, 11:52pm
Yep, I have replaced many and simply cut the wires / rewire into new one.

TIP = Before youslash the wiring use a test lamp / meter to figure the power up to the power down.

pdc1, Sep 11, 12:13am
Thanks Ceebee. I can work out the motor wires ok. It's just the antenna cable itself that I was concerned about. Don't want poor reception!

tmenz, Sep 11, 1:47am
Best done with a coax plug and socket of some sort that will fit the cable unless you are adept at butt-joining coax cables and preserving the braid shielding over the joint.

http://www.jaycar.co.nz/productResults.asp!keywords=car+radio+antenna+line+socket&keyform=KEYWORD http://www.jaycar.co.nz/productView.asp!ID=PP2041&keywords=auto+antenna+plug&form=KEYWORD

andrea_w, Sep 11, 2:02am
OP - Here are some pics you can use as a guide to join the aerial together. this is the method that was taught to me when I did car audio for a living .and yes, it's absolutely fine to cut the aerial, it won't affect reception at all if it's re-joined correctly!
The most important things are;
Make sure the outer core does NOT touch the inner core - even a single stray strand of copper will ruin reception.
Be gentle with the inner core, sometimes it's just a single very thin wire that's easily broken.

http://i198.photobucket.com/albums/aa19/BADHABIT_R33/Car%20audio/AerialRepair1.jpg http://i198.photobucket.com/albums/aa19/BADHABIT_R33/Car%20audio/AerialRepair2.jpg http://i198.photobucket.com/albums/aa19/BADHABIT_R33/Car%20audio/AerialRepair3.jpg http://i198.photobucket.com/albums/aa19/BADHABIT_R33/Car%20audio/AerialRepair4.jpg http://i198.photobucket.com/albums/aa19/BADHABIT_R33/Car%20audio/AerialRepair5.jpg!t=1318186050 http://i198.photobucket.com/albums/aa19/BADHABIT_R33/Car%20audio/AerialRepair6.jpg http://i198.photobucket.com/albums/aa19/BADHABIT_R33/Car%20audio/AerialRepair7.jpg http://i198.photobucket.com/albums/aa19/BADHABIT_R33/Car%20audio/AerialRepair8.jpg http://i198.photobucket.com/albums/aa19/BADHABIT_R33/Car%20audio/AerialRepair9.jpg

supernova2, Sep 11, 3:20am
http://www.jaycar.co.nz/productView.asp!ID=PS0618&keywords=coax+joiner&form=KEYWORD

That will do it for you if you dont feel comfortable doing it andrea_w's way (which I'd do but with heat shrink tube rather than tape)

pdc1, Sep 11, 6:36am
Thanks everyone. I'll be doing it andrea's way. I hadn't thought to use the crimp fitting in the central wire. Good idea to give it support.
Radios and antennas are witchy poo stuff to me. I didn't know if it was critical to how they work , with the length of the cable, joins etc.