pepe63xnotuse Posted March 22, 2011 Share Posted March 22, 2011 I'm running a cable for an external aerial point and I was wondering if it would be okay to leave the surplus cable coiled up under the false floor of the wardrobe,in amongst the "rats nest" of cables left by the converter?..or would/could this lead to interference? Thanks Chris Link to comment Share on other sites More sharing options...
Rayjsj Posted March 22, 2011 Share Posted March 22, 2011 Why have a lot of excess ? once it is routed cut off the excess and fit the plug. They say that routing aerial cable alongside 240v. mains cable is not a good idea, as the e,magnetic 'fuzz' can get through the screening of the coax. Don't know if thats true, as i have never experienced any interfereance bad enough to worry. A coiled 'rats nest' of odd cables may also give off interfereance, although it will mainly be only 12v wont it ? I always think it's best to keep wiring 'tidy like' , (drummed in during apprenticship) and to follow recommendations. Ray Just done this same job in my own van. Link to comment Share on other sites More sharing options...
thebishbus Posted March 22, 2011 Share Posted March 22, 2011 Hi . Also remember that because of the internal resistance/capacitance of the cable, the signal strength reduces with cable length, keep it as short as possible. Brian B Link to comment Share on other sites More sharing options...
Corky 8 Posted March 22, 2011 Share Posted March 22, 2011 Why not start off as you intend to go on,by making all your DIY jobs neat and tidy ones,use the correct Cable bridges to hold the coax up and away from other cables, remembering the shorter the run of any electric/signal carrying cable the less resistance, plus any electrical cable should not really be coiled when in use ,same with your electrical hook up cable open it right out when in use. Link to comment Share on other sites More sharing options...
lennyhb Posted March 22, 2011 Share Posted March 22, 2011 Use a good quality satellite cable with foil screening, there is a vast difference in cable quality. If possible when crossing mains cables do it at 90 deg & try to avoid running along side them. I would cut off the excess but leave bit of slack so if you need to replace sockets it will be easy. Link to comment Share on other sites More sharing options...
Clive Posted March 23, 2011 Share Posted March 23, 2011 Losses in coax are proportional to its length, however coax lengths provided for vehicle use are not large. If its coiled up then chose somewhere without any other cables nearby which might cause interferance. C. Link to comment Share on other sites More sharing options...
pepe63xnotuse Posted March 23, 2011 Author Share Posted March 23, 2011 Thanks for the replies.. Point taken about making it neat from the off... :$ (..I tend to usually be overly neat when running cables and such like,it's just that when faced with the rats nests of cables the converters leave,it does sometimes seem a little pointless..) ..also, "for now" I'm not using a proper external point,I'm just feeding a length of coax,down through an existing cable entry point and into an external locker(..we've got a "thru the roof" aerial,which is fine 9/10 but occasionally we've needed the sites aerial point). I was a bit reluctant to cut off the excess cable ..in case I end up changing my mind where I site the socket(..which I'm bound to do once I've cut it! *-) ) Also I get the point about the length effecting the performance..but as we'll need to be plugging in a ruddy great extension cable in order to reach the sites' aerial socket,I shouldn't think my extra couple of mtrs would make that much difference... (lol) As interference can be a problem,I will certainly keep it away fom the other cables where possible.. Thanks all.. Chris Link to comment Share on other sites More sharing options...
lennyhb Posted March 23, 2011 Share Posted March 23, 2011 Clive - 2011-03-23 7:43 AM Losses in coax are proportional to its length, however coax lengths provided for vehicle use are not large. If its coiled up then chose somewhere without any other cables nearby which might cause interferance. C. In principle yes but I've come across cheap cable & fly leads where the signal loss has been significant over as little as 2m, with digital transmissions this can be the difference between picture & no picture. Link to comment Share on other sites More sharing options...
spospe Posted March 23, 2011 Share Posted March 23, 2011 lennyhb - 2011-03-22 7:06 PM Use a good quality satellite cable with foil screening, there is a vast difference in cable quality. If possible when crossing mains cables do it at 90 deg & try to avoid running along side them. I would cut off the excess but leave bit of slack so if you need to replace sockets it will be easy. The OP did not say if the intention was to use a terrestrial or a satellite aerial and this does have an important consequence in that co-ax cable may be either 50 or 75 ohm impedance depending on what type of aerial / equipment is to be fitted. This does not affect any of the advice on running the cable, or making it tidy but it is important to get the right impedance cable for the job (just trying to be helpful). Link to comment Share on other sites More sharing options...
pepe63xnotuse Posted March 23, 2011 Author Share Posted March 23, 2011 Blimey..you're getting a bit technical for me now :$ Sorry,I should've been clearer..I'm only using it for digi tv and as for the cable,well I'm just using a reel I had left over,which came with a domestic aerial kit(...so probably not the best of quality then..) ...but it is what we have used on site from time to time,just poked through the window... Chris Link to comment Share on other sites More sharing options...
lennyhb Posted March 23, 2011 Share Posted March 23, 2011 spospe - 2011-03-23 9:32 AM lennyhb - 2011-03-22 7:06 PM Use a good quality satellite cable with foil screening, there is a vast difference in cable quality. If possible when crossing mains cables do it at 90 deg & try to avoid running along side them. I would cut off the excess but leave bit of slack so if you need to replace sockets it will be easy. The OP did not say if the intention was to use a terrestrial or a satellite aerial and this does have an important consequence in that co-ax cable may be either 50 or 75 ohm impedance depending on what type of aerial / equipment is to be fitted. This does not affect any of the advice on running the cable, or making it tidy but it is important to get the right impedance cable for the job (just trying to be helpful). TV Aerial or Satellite cable is 75 ohm, 50 ohm cable is used for industrial applications or composite video distribution. Link to comment Share on other sites More sharing options...
AliB Posted March 23, 2011 Share Posted March 23, 2011 Composite video can be 75 or 50 ohms. For example, most reversing cameras are 75 ohms composite video. Cable quality varies hugely these days due to the fluctuating prices of copper. The best quality coaxial cables have a copper core and use copper braiding as the screen. Lower cost cabling called CCA, copper clad aluminium, is increasingly being used. This will typically has an aluminium foil for the screen. CCA cable is perfectly adequate for video runs on domestic TV distribution systems or cameras where the cable runs are not long. To answer the OP question, there should be no problem coiling the cable apart from already mentioned factor of keeping it tidy and observing best practice. Link to comment Share on other sites More sharing options...
lennyhb Posted March 23, 2011 Share Posted March 23, 2011 AliB - 2011-03-23 1:43 PM Composite video can be 75 or 50 ohms. For example, most reversing cameras are 75 ohms composite video. . I was referring to industrial video distribution through large buildings, with the short run of a reversing camera it doesn't make much odds most are supplied with cheap audio cable. Link to comment Share on other sites More sharing options...
pepe63xnotuse Posted March 23, 2011 Author Share Posted March 23, 2011 It's all done and tested now..AND it works! 8-) I kept the cable reasonably short'n'neat in the end..as hopefully I won't be repositioning it anywhere else. Can I just ask an additional question? We've got one of the Status 530 "thru the roof" aerials and booster box thingy.. ..Am I correct in thinking that when using the external aerial point,the "box" should be bypassed and the external lead plugged directly into the lead to the tv? (..or does the box offer a switched/selector option?) ..although to be fair,even when using the onboard aerial,it doesn't seem to make any odds whether the box is on or off anyway..?! :-S ) Thanks again Chris Link to comment Share on other sites More sharing options...
Rayjsj Posted March 23, 2011 Share Posted March 23, 2011 The 'piped' signal from CC bollards is already 'Boosted' so boosting it again is bit of a waste, and boosts interferance as well, so, just bypass the Status box. As I said I have done the same job, I put an exterior socket onto my van. E-bay : http://cgi.ebay.co.uk/CARAVAN-MOTORHOME-EXTERNAL-TV-AERIAL-SOCKET-096016-NEW-/140508642501?pt=UK_Campervan_Caravan_Accessories&hash=item20b6f7bcc5 looks nice and tidy, and works fine. Ray Link to comment Share on other sites More sharing options...
Guest Tracker Posted March 23, 2011 Share Posted March 23, 2011 pepe63 - 2011-03-23 2:19 PM ..although to be fair,even when using the onboard aerial,it doesn't seem to make any odds whether the box is on or off anyway..?! :-S ) Well it should do - although not always but particulary in weak signal areas! Is it wired up correctly as with so many plugs and sockets to choose from it can get confusing - and does the red light glow when fed with 12v and switched on? Have you tried it on analogue as sometimes you can still get a decent picture on analogue out in the sticks when digital fails - but not if analogue has been turned off! Link to comment Share on other sites More sharing options...
pepe63xnotuse Posted March 24, 2011 Author Share Posted March 24, 2011 I see,I didn't think the "booster" was used when using the external aerial. The box is wired okay..I suppose we must've just been lucky with the sites we've used and the "booster bit" hasn't been needed anyway... ;-) To be honest we don't use the tv that much(..it's only usually when the 6 nations is on.. ;-) ) Thanks again... Link to comment Share on other sites More sharing options...
pepe63xnotuse Posted March 24, 2011 Author Share Posted March 24, 2011 Me again!(..tried to edit previous post but missed the "deadline" :$ ) Just another small quiry about the booster box.. Instead of having to fiddle around at back of the wardrobe,unplugging leads,would it be okay if the two aerial leads(for the onboard aerial and external point),were both permenantly connected to the booster via a "Y" splitter?(...and just leaving the booster "off" when using an external aerial?) or would that cause the signal to get distorted? Chris Link to comment Share on other sites More sharing options...
Keithl Posted March 24, 2011 Share Posted March 24, 2011 Hi Chris, The 'Booster' pack as you describe it is not actually a booster but a 'Power' pack that feeds a small voltage up the co-ax to an amplifier built into the aerial. When in use the red LED should light, if not refer to the fault finding section of the instructions. You can download them from the Grade website if you haven't got a copy. As for using a splitter after the power pack to feed in the new lead, I don't see a problem in doing this and I'm sure others will be along soon if they disagree :D Keith. Link to comment Share on other sites More sharing options...
Robinhood Posted March 24, 2011 Share Posted March 24, 2011 Keithl - 2011-03-24 12:40 PM Hi Chris, The 'Booster' pack as you describe it is not actually a booster but a 'Power' pack that feeds a small voltage up the co-ax to an amplifier built into the aerial. When in use the red LED should light, if not refer to the fault finding section of the instructions. You can download them from the Grade website if you haven't got a copy. As for using a splitter after the power pack to feed in the new lead, I don't see a problem in doing this and I'm sure others will be along soon if they disagree :D Keith. Keith, I think you're only half right here, and I also think you've misinterpreted what Chris is suggesting. For the early units (Purple power pack matching a purple "head" on the aerial), the unit was simply a powerpack, with the amplifier in the aerial; power was transmitted up the coax from the powerpack to the aerial-embedded amplifier. Later units with the Orange pack and head appear to have an amplifier built in to the powerpack (it can also be used with the basic free-standing aerials). Check the website www.gradeuk.co.uk for details. From this information, I had assumed that power was no longer transmitted up the coax to an "in-head" amplifier for orange units, but, after some problems with the installation on my current 'van (the first orange unit I've had), I'm not convinced that it doesn't still provide such power. I think Chris was suggesting putting a splitter on the input coax side of the powerpack, not the output as you have commented on. I would suggest that this is not a good idea. If the unit is outputting a voltage up the coax, I wouldn't like to take the chance of what effect that would have on an active distribution system, should the power be inadvertantly switched or left on. (under similar circumstances, I managed to mess-up a home distribution system by feeding amplifier power up the coax into a distribution box that wasn't expecting it :-S ). In addition, there is the chance that (switched off) the circuitry in the powerpack will degrade the incoming "site" signal. To achieve a simlar result, I've simply run the external coax to the location of the powerpack, terminated with a coax socket. If I want to use the site signal, I just unplug the powerpack signal output, and plug it into the external coax. (if there is a plug fitted to the external coax, a double-female coax joiner will do). Link to comment Share on other sites More sharing options...
pepe63xnotuse Posted March 24, 2011 Author Share Posted March 24, 2011 Hi Keith Yeah,the box does work(..it needs switching on to get a signal on our drive)and with the splitter in place,the onboard aerial seems unaffected...so I'm assuming the external would be okay as well... Thanks for the link to their site. Edit:Sorry Robin' I misssed your post... Well if you feel that what I suggested may cause problems,then I'll just plug in the lead to the external point as/when needed. ..which is what I originally intended to do before I got "lazy"(..all this unplugging and plugging in of leads can be SOoo tiring you know.. (lol) ) Chris Link to comment Share on other sites More sharing options...
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