| Author | Message | ||
     Nick Bellistri (Nickbell) New Member Username: Nickbell Post Number: 40 Registered: 11-2002 |
I am installing a CB. for my antennae ground i was going to ground it to the chassis as suggested by the folks at www.firestik.com. they suggested 12 gauge as being sufficent. i have some 4 gauge laying around and was planning on using that to make a really bomber ground... is 4 gauge to big? | ||
| Joel Dorfan (Streak) New Member Username: Streak Post Number: 1 Registered: 03-2003 |
No problem with going larger than 12 guage. Just make sure that the two connection points are clean and that there is a good path to earth for the antenna mount. Make sure that once the antenna is in position and grounded, that you check the SWR to make sure that all is in order. You may need to adjust the length of the whip to optimise the SWR. http://www.worst4x4.freeservers.com | ||
| phil (Powerslide) Member Username: Powerslide Post Number: 49 Registered: 11-2002 |
Besides the ground on the antenna, it also helps if you have a good ground on the CB chassis/mount itself. And if your negative wire is tied directly to the battery posts it also helps. This is where more grounding helps and the output improves with a bigger ground plane. | ||
| Nick Bellistri (Nickbell) Member Username: Nickbell Post Number: 41 Registered: 11-2002 |
i just tuned it and everything looks like its working well | ||
| Nick Bellistri (Nickbell) Member Username: Nickbell Post Number: 42 Registered: 11-2002 |
I am getting a ton of engine noise... its a whirring noise. from the info in the archives apparently this is an alternator generated noise...i guess the high output alternator isnt helping here  according to the swr meter everything is fine and 'properly'. i have re routed the antennae cable to have as little cable as possible near the engine. i was thinking of buying 20 amp noise filter from radio shack, and possible get an a filter for the antennae cable. Would a low pass TVI filter work? also any suggestions to rid of the whirring noise is appreciated | ||
| phil (Powerslide) Member Username: Powerslide Post Number: 51 Registered: 11-2002 |
You don't want to put a filter on your antenna as it will affect your output and really not help with the noise. Do you have resistor type spark plugs? Noise suppression ignition wires? You can also add a ferrite bead / choke on the power line (+) of your CB unit. HTH. If anything else, turn up the squelch all the way. | ||
| Streak (Streak) New Member Username: Streak Post Number: 2 Registered: 03-2003 |
When you experience the whining, unplug the antenna to confirm that it is coming from the power cable rather than from the coax cable. There are capacitors you can get designed to fit onto the alternator which reduce or eliminate this noise. You can aslo get a A line choke designed to filter out other kinds of power line based noise. Also, as Phil said, make sure that your HT leads are in good condition and that both them and the plugs are supressed. | ||
| Nick Bellistri (Nickbell) Member Username: Nickbell Post Number: 43 Registered: 11-2002 |
the spark plug wires are magnecore and the plugs are the stock champions. i will try unplugging the antennae today and see what happens | ||
| Nick Bellistri (Nickbell) Member Username: Nickbell Post Number: 44 Registered: 11-2002 |
unplugged the antennae and some of the noise stopped but there was still some noise... i am going to install a noise filter on the power line. also i realized that the alternator and the antennae are grounded to the same place on the chassis. is there any chance that this is causing the noise. i dont think so but i thought id ask.. | ||
| Streak (Streak) New Member Username: Streak Post Number: 3 Registered: 03-2003 |
Finding sources of noise can be a pain in the A$$. First determine if it is ignition or alternator noise. By your description it sounds like alternator whine. If you have another 12v battery handy, try and connect the CB to this separate power source and see if you still have noise, this will help determine if you need a power line choke. I think, from what you describe that the alternator capacitor is the way to go. The whole car has a common ground anyway so no problem about the place on the chassis. Did the antenna come with it's own coax cable and molded PL259 plug or did you add the coax and plug yourself? | ||
| Nick Bellistri (Nickbell) Member Username: Nickbell Post Number: 45 Registered: 11-2002 |
i added the coaxil and plug. re routing the wire seemed to cure a lot of problems, but there is some noise still left. it seems to becoming from both the antennae and power source. is the alternator choke a common item or is there any place ud recommend online? | ||
| Jerry Crawford (Jcrawford) Member Username: Jcrawford Post Number: 60 Registered: 08-2002 |
Nick - if you have your radio powered through the electrical system of the truck (Cig lighter, fuse block, etc)you will get engine feedback. Run a dedicated fused wire off the positive terminal from your battery and your engine noise should go away. If you are going to also operate extra lights you should already have an auxillary fuse/relay block operating that is fed directly fromthe bat. Just tap another circuit from this for your CB. As an aside - where are you mounting your antenna? I ask because bumper mounts suck and retard your trans/recept. Just something to think about. FMI go to my web siteand read some of the tech stuff there. Jerry | ||
| Streak (Streak) New Member Username: Streak Post Number: 4 Registered: 03-2003 |
Make sure you are using good quality screened 50 ohm coax and that you have fitted the plug correctly using solder. You can see a picture of an alternator capacitor here http://johnsmustang.com/Catalog/2311/ , the price on this site is crazy, should not cost you more than a couple of dollars from a spares or stereo fitement store. I am in South Africa so cant help you with a store name. | ||
| Nick Bellistri (Nickbell) Member Username: Nickbell Post Number: 46 Registered: 11-2002 |
I have it directly wired from my aux battery... the antennae is mounted to my front bumper. i have a RR Classic so i cant mount it on the rear door or bumper. i was trying to avoid putting in on the top of my car b/c i dont want it to get ripped off when offroading. i could just be splitting hairs w/ this noise now. i am guessing it will work on the trail. right now im just picking up general chatter from ppl on the highway | ||
| Jerry Crawford (Jcrawford) Member Username: Jcrawford Post Number: 62 Registered: 08-2002 |
bumper mountings are problematic because so much (can't recall the %-age at the moment) of the transmitting energy is radiated from the bottom part of the antenna. On front bumpers your truck masks all the signal going to the fokes behind you and you wind up only communicating with the guys up front. (shrugs his head and thinks "I gotta come up with a good antenna mount for RR's) | ||
| Nick Bellistri (Nickbell) Member Username: Nickbell Post Number: 47 Registered: 11-2002 |
hmm never thought about the guys in back of me. if u are ever interested in fabbing something drop me an email, u can use my car as a model. i live in mass so the drive wouldnt be bad. the only place i can think is some place on the rain gutters. but w/ a roof rack it gets hairy | ||
| Nick Bellistri (Nickbell) Member Username: Nickbell Post Number: 48 Registered: 11-2002 |
i have noticed the engine sound is more promimentent at the high channels or is that just me pullin stuff out of nuthin | ||
| Jerry Crawford (Jcrawford) Member Username: Jcrawford Post Number: 63 Registered: 08-2002 |
well, sometime ago I heard "whatever the mind of man can concieve and believe...it can achieve" [wish I'd said that]. But, a mount for the RR is probably doable. As you said I'd need a model to work on for a few hours. I have a LR Series & Defender importer chap up in canada waiting for mounts for them as well. This winter has prevented me from taking that task - can't work in a garage with no heat when it's 20 below. Drop me a note off line and maybe we can get together. I'm about 2 hours up 95 (Exit 4 in Maine) from the 495/290 split going into Worcester. | ||
| Nick Bellistri (Nickbell) Member Username: Nickbell Post Number: 49 Registered: 11-2002 |
how about a NGP antennae? | ||
| Jerry Crawford (Jcrawford) Member Username: Jcrawford Post Number: 64 Registered: 08-2002 |
don't - they are a compromise - read the tech section on the Firestik web site and they will tell you about NGP. They are used on Fiberglass bodied vehicles like motorhomes and cars and aren't worth the money for our use. You have a perfectly adequte ground plane in your truck. take advantage of it. |
