20 Most Recent Cobra 19 DX IV CB Radio - Page 2 Questions & Answers

none buy a power mic

look inside radio at the components. you will see the transformer and a variable next to it . turn the variable clockwise wide open then back it off a bit. this should improve your modulation.

L36 and tr-32 amc vr 7 ALC /vr6 aqm pwr

crack in the pcb board ?bad wire somewhere.? main IC not powering things up.

switching diode or resistor in line with it no good

adjust the SWR and you may just find your volume

check squelch and wires to the speakers

You might try grounding the CB and the Kenwood. It seems that there is stray rf floating around. Check your antenna. Make sure it is getting a proper ground. If mag mount; make sure base of antenna and where you put it are both super clean. Check where whip goes into coil or base. Make sure all allen screws are tight and whip is not either all the way down to the base or up to the top. If antenna is mounted; make sure that it has a good ground. You might have to remove some paint around the base to get a good connection. DO NOT TRANSMIT WITH A HIGH SWR. YOU CAN BURN OUT THE EXPENSIVE POWER OUTPUT TRANSISTOR. Hope it helps.

don't cut or increase watts.Check it out first as you may want to turn down wattage. Cutting or clipping a radio is not good . over modulation could cause a problem not only with the radio but with those you talk with. You will be slashing your modulation waves over the whole band any if it interfears with them they won't be happy. you can get all the information you want on www.cbtricks.com

is it wired direct to fuse box or is it to a lighter plug? the plug will make a lot of ground noise. try different ways until you clear it up. one way is a noise clipper from H +Y

bad ground possibly.

Does your "pete" have a fiberglass body? I suspect it does. If this is the case and you are using mirror mount antennas, are they the new "no ground needed" or "ground free" antennas?
If this is the case, check or have checked your SWR. (I get a lightening bolt down my neck when I hear it called "SWR'S".)
S.W.R. stands for Standing Wave Ratio. In the words of The Highlander, "There can only be one". What this is is the amount of your signal that is being absorbed / radiated by your antenna system, (including your coax), as opposed to how much is being sent back down the coax and back into your radio. If your SWR is too high, not much is going out the antenna and is being reabsorbed by your RF FINAL, (another bolt!!!). Most radios except for some modified hams or high power exports HAVE ONLY ONE FINAL TRANSISTOR!!!. If you have a standard Cobra 29 out of the box, you have ONE final TRANSISTOR. I don't mean to yell at you. These are just my pet peaves.:) Anyway, imagine that you have a rope tied to a building. You pull it fairly taught and whip it up & down once. That wave will move away from you, hit the building and come back and shake your hand. This is high SWR as all of your power came back to you. If Superman were to shake that same rope and that wave took that building off it's foundation, this low SWR as all of his power was radiated by the building. This is how you want your antenna system to work. If your SWR is too high, your radio is trying to put out 4 watts. That same 4 watts is coming back down the line out of phase and now your final is being asked to handle 8 watts when it will only made to do 4, (all in a perfect world of course:). If you were fooled into buying these "no ground" antennas as so many truckers are, I am sorry. These should only be used as a last resort when nothing else works. These antennas have what's called a matching stub in their coax plugs in the case of the single mast marine type antenna or the antennas, (in the duals), have a matching capacitor in them. Both of these "tricks" fool the radio and SWR meter into thinking that the match on the system is acceptable when it really isn't. For electronic reasons that are really too long to explain here, (you really don't want to get me started:), the low SWR reading is only an illusion. Instead of your signal being radiated completely by your antenna, a major portion of it is being absorbed by either the matching stub or matching capicitors. All of this energy has to go somewhere so some is converted into heat energy in the matching circuits and some is re-radiated to the nearest ground. Unfortunately that will be the wiring of your truck especially if the body is fiberglass which does nothing to stop radio waves.
If you get a weekend off and your boss, (if you're not an owner / operator), doesn't mind you taking your truck home for the weekend. If you know someone with a pair of antennas and a co -phase harness that they can loan you. Set up your mirror mounts in normal fashion with STANDARD antennas. Run your co-phase harness where it won't get pinched up to your radio.
Here's the trick, gain access to the inside of BOTH doors, get ahold of some coax SHIELD braid. Preferably something heavy like off from RG-8 or atleast RG-8X. Get to the nut that holds the mirror to the door that is closest to the door hinge on BOTH DOORS. Clean it up with sand paper so it's nice and shiney AT BOTH ENDS and wrap 1 loop of braid around that bolt inside the door, put a flat washer over the braid and put the nut back on tight without breaking it of course. Take the other end of the braid to 1 bolt of the door hinge, clean it up shiney under the bolt head and matching surface of the hinge, wrap a loop of braid around then bolt and tighten it up. Be sure to leave enough slack in the braid so you don't rip it out when you open the door. Wire will work but braid is better. If you can get ahold of the wide ground strap like they used to use to ground car bodys to their engines, the bigger the better. Radio waves travel on the OUTSIDE of any conductor. Braid has more surface area than a piece of wire. BEFORE you transmit, get the SWR checked and adjusted if possible and/or necessary. I say to borrow the equipment rather than buy it at first because this works in about 85% of installations and I'd hate to see you invest in a new antenna system to find out you're one of the 15%. If this is your problem and this fix works, you'll be amased at how much farther you'll get out with all of your power making it's way out rather looking like the northern lights around you.
Good luck,
I'm going to bed now, (7:33am here). Hey, 73's to ya'.
Jeff Mc.

Modulation being muffled could be the mic or it could be an adjustment in the unit.

per fcc rules (laws)? you cannot put an amp on a cb. max output 4 amps. you should be able to put a pa speaker using the pa output jack. take your radio back for warranty.

check the mics wiring if the mic is not right on some cbs the sound goes off

You'll need to find another CB radio for someone to check to see if they are receiving your transmission.

Hello kaelea,

 

Check your ground wire and by your post I gather that you are user some form of headphone device, I say this because normally the speaker is off when the microphone is keyed. I would also check the controls on the headset if you are using one.

 

I hope this helps,

 

Thank you,

Shuttle83

check the frequency,these radios are good for the money,but drift off frequency,try different channels and see if that helps

First, stop transmitting. If your antenna system is compromised, transmitting can cause damage to the output transistors are require an expensive repair to correct.Carefully check the entire length of the coaxial cable from the rear of the radio to the base of the antenna. Pay attention to pinch points between body panels, door openings, etc. Crushed coaxial cable results in a short circuit and must be replaced. Chafed or an otherwise damaged outer jacket on the coaxial cable will allow water to enter and contaminate the dielectric and oxidize copper braid and center conductors. This type of damage requires replacement, too. Inspect the connector at the radio. Make sure that the soldered joints in the connector are still secured and have not broken and caused an open circuit or short circuit. This connector should be snugged up hand tight to the radio's connector.Check the feed point of the antenna. This connection is often subject to moisture and can oxidize quickly. Look for evidence of oxidation and other open or short circuit conditions here. Cut the coax back until all the oxidized cable is not longer visible and reconnect to the antenna feed point. If possible, coat this connection completely in a thin coating of silicone to keep water from attacking the connections or entering the coaxial cable.Check any connections between the antenna base and the antenna itself. Many antennas allow for removal for car washes, etc. by unscrewing / quick disconnect from the base. Clean threads or retaining pins on both the base and antenna thoroughly. Check the center pin contacts on the base and antenna for evidence of good contact. Oxidized surfaces here can indicate a poor connection. Clean or replace as needed.Make sure that the surface to which the antenna is secured (tool box) is solidly grounded. One or more large conductor bonding jumpers from grounded vehicle panels, frame, etc should be extended to the tool box. A tool box that merely sits on / bolted to the truck's bed is probably not providing enough contact with unpainted, grounded body panels to provide sufficient ground for the antenna system to work well. Check the tuning slug at the end of many fiberglass antennas. It should be present, and have the protective cover to seal out the entry of water.Lastly, after the above has been addressed & corrected, tune the antenna to the radio on the truck with a quality SWR meter for the frequency range of the CB as per instructions.I hope this helps & good luck!