muddy Posted October 9, 2012 Share Posted October 9, 2012 Evening all having just got my disco on the road I want to fit a radio to it, I will be fitting twin CB arieals (cos I is cool innit) one for the CB. And one for the radio, I know you can get a splitter but they are £20 ish, tonight I was playing around and bared back the existing vehicle arieal wire and soldered the central core to a blue ring connector and screwed this onto the back of a cb arieal mount (surface mount jobber that goes on a flat vertical surface) and with a 5ft whip a head unit that usually struggles for reception had perfect sound in my workshop where it never did in my 90. So my question is can I just buy a (pl80??????) standard cb co ax connector and solder it onto the end of a fm radio coax or can I get the fm head unity type plug to solder onto the end of my cb coax? Should I be trying to do anything in particular? I have an abundance of broken/unused cb mounts and bits of coax hence trying to use it up as can't quite bear to throw such useful tat away. Hopefully some of that makes sence, I've taken to the cider after going basil faulty on my old head unit with a 28lb sledge hammer after spending over 2 hours soldering and unsoldering an ISO plug trying to work out what had gone wrong when it was a short on the head unit. Cheers, Will. Quote Link to comment Share on other sites More sharing options...
landy V8 Posted October 10, 2012 Share Posted October 10, 2012 just to be picky,one is an Aerial(radio) and one is an Antenna(cb). an aerial recieves only whereas an antenna recieves and transmits. Quote Link to comment Share on other sites More sharing options...
Landy'd Gentry Posted October 10, 2012 Share Posted October 10, 2012 I would avoid using one ariel for both cb and fm radio as all you will ever get is a comprimise! The fm radio recieves on 87.5 - 108.0 Mhz, where as the CB transmits and recieves on 26.9650 - 27.99125 Mhz. Receiving isn't the problem, it's the transmission part. Get the ariel wrong, and you'll have swr issues and possibly blow your rig (worst case scenario) Best just to have one ariel for each system! Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted October 10, 2012 Share Posted October 10, 2012 He is using seperate aerials/antenna, one for radio and one for cb. As for which coax to use CB coax has 50 ohm impedance and FM radio coax has a 75 ohm impedance. The head unit's aerial input should be designed for 75 ohm impedance, using a mismatched cable and aerial would result in less power being transferred at each mismatch point, there is always a mismatch between the aerial and cable (this is where the SWR comes from with CB's unless of course you have a 1:1 SWR) . I'd stick with the FM coax (75 ohm) if you are planning to use the CB antenna as an aerial. Quote Link to comment Share on other sites More sharing options...
muddy Posted October 10, 2012 Author Share Posted October 10, 2012 Ok do if o get a PL259 connector and solder it to the end of an Ariel extension lead from the motor factors o can use one of my cb antennas as an Ariel for the fm radio and keep the other antenna for the cb. Second question, do the PL259 connectors fit in just the same way as sky/telly co ax connectors ? Will. Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted October 10, 2012 Share Posted October 10, 2012 I think they screw on to the coax (like a sattelite f connector) and you solder the centre pin (like a tv coax connector). It's a while since I fitted one so the memory is a bit fuzzy. If you look on ebay they are available for different sized cables to that would match my addled memories. Quote Link to comment Share on other sites More sharing options...
western Posted October 10, 2012 Share Posted October 10, 2012 Ok do if o get a PL259 connector and solder it to the end of an Ariel extension lead from the motor factors o can use one of my cb antennas as an Ariel for the fm radio and keep the other antenna for the cb. Second question, do the PL259 connectors fit in just the same way as sky/telly co ax connectors ? Will. This should explain http://www.saltyjohn...axial cable.pdf & http://www.gme.net.au/public/pdf/brochures/pl259_instructions.pdf Quote Link to comment Share on other sites More sharing options...
HoSS Posted October 10, 2012 Share Posted October 10, 2012 just to be picky,one is an Aerial(radio) and one is an Antenna(cb). an aerial recieves only whereas an antenna recieves and transmits. I hate to be picky also - but the 2 words are synonyms. Theres no such meaning. Quote Link to comment Share on other sites More sharing options...
muddy Posted October 14, 2012 Author Share Posted October 14, 2012 Thanks for the advice, now have a working radio in the milkfloat, as soon as my other mount arrives I shall get the cb in. Now I've mounted them on a lightbar would I benifit from running an earth strap to the roof/ body or chassis? Will. Quote Link to comment Share on other sites More sharing options...
western Posted October 14, 2012 Share Posted October 14, 2012 if the SWR sets for the CB is 1.3 or less then you don't need to do anymore these 2 threads would be worth your reading, if you haven't already done so. http://forums.lr4x4.com/index.php?showtopic=37466 http://forums.lr4x4.com/index.php?showtopic=5374 Quote Link to comment Share on other sites More sharing options...
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