cb ant
- Thread starter Iron mule
- Start date
1)Check your coax and make sure its connected tightly at both ends,not corroded or has a cold solder joint and not shorted out. You can check for a short with a simple circuit tester or if you want,disassemble your flashlight and use the batteries and bulb(this takes three hands and patience,but it will work)Check the inner conductor,the outer conductor and the inner against the outer to see if you have current flow. The last being the most important. If you have current flow there,it's shorted.
2)Clean your antennas. Dirty,bug covered,greasy antennas don't receive/or transmit well. Check for nicks and cuts if it's helically wound. If your prone to hitting low hanging things,i.e. tree branches,it might have a broken conductor inside and this will change the electrical length of the antenna circuit,throwing it out of match and causing it to receive poorly. If you have coils and steel whips vibration could have broken a connection inside the coil. If you can disassemble the coil,check it. Check all of the screw together points for corrosion/tightness. Also,check to ensure proper grounding. An antenna that doesn't require a ground plane for fiberglas bodies,or a ground strap to the nearest metal screw to metal body part,should cure that aspect.
3)Check the S.W.R.. An improperly matched antenna works but,power during transmission is dissipated as heat at the finals or on the antenna instead of radiating out due to resistance. Matching has just as much effect on transmission as it does on receiving. An antenna of improper electrical length,being a mismatched circuit,will receive poorly.
3a) Unrelated,but just as important,on the SWR side of things. DON'T COIL EXCESS COAX IN A LOOP. It sets up standing waves on the coax that create a mismatch. Coil it up in a circle wrapped around your thumb and elbow,then twist the loop in a figure eight and flip it back on itself and fasten it with a wire tie. The figure eight flips the field of standing waves 180 degrees out of phase with the other half of the loop and "cancels out" the majority of the standing waves. Just an extra tidbit.
4)Maybe it's not your antennas or coax. Some radios are equipped so that their audio circuit goes through the microphone. This can be checked if you have a disconnectable mic. If you unplug it and your sound cuts out,it's wired through the mic. If you have a bad/loose connection inside the mic plug,at the radio end or at the switch in the mic head,it can affect audio output at the speaker, creating the illusion of bad reception.
5)If you're running heat,depending on the wattage,your coax may have fried/shorted itself due to exceeding the maximum rating. Using thicker RG/8U instead of the thinner "normal" sized RG/58U will alleviate the penchant for shorting,but it will not affect XMIT or RCV,except that a better coax(shielding contained within)aids in ensuring that more of the signal,incoming or outgoing,makes it to it's destination and it'll handle more power.
6)And last but not least,it could be your audio chip/circuit inside the radio,again creating the illusion of bad reception. Try all I've suggested FIRST,if it results in no change,I'd suggest consulting a technician of good repute. Your chip may have a loose solder joint or be close to kicking due to vibration.
As for a question of what KIND of antenna to put on your truck,it's buyers choice. Longer lengths of antenna tend to do better. This is however C.B. and they're not designed to communicate more than five miles at best,so don't expect much when transmitting the allowed four watts or receiving over three miles.
I wouldn't advise if I didn't design my own antennas for use in the freeband space above 40 channels to talk skip. I am not a tech but, I think I've enough experience in antenna design to know a few things. I am also a driver of 12 years to know the environment of a truck to know these radios/accessories get beat. At best maybe one of my suggestions will help. At worst you'll be taking it to a tech anyway. I hope I have been helpful.
Kenny(PJ)
2)Clean your antennas. Dirty,bug covered,greasy antennas don't receive/or transmit well. Check for nicks and cuts if it's helically wound. If your prone to hitting low hanging things,i.e. tree branches,it might have a broken conductor inside and this will change the electrical length of the antenna circuit,throwing it out of match and causing it to receive poorly. If you have coils and steel whips vibration could have broken a connection inside the coil. If you can disassemble the coil,check it. Check all of the screw together points for corrosion/tightness. Also,check to ensure proper grounding. An antenna that doesn't require a ground plane for fiberglas bodies,or a ground strap to the nearest metal screw to metal body part,should cure that aspect.
3)Check the S.W.R.. An improperly matched antenna works but,power during transmission is dissipated as heat at the finals or on the antenna instead of radiating out due to resistance. Matching has just as much effect on transmission as it does on receiving. An antenna of improper electrical length,being a mismatched circuit,will receive poorly.
3a) Unrelated,but just as important,on the SWR side of things. DON'T COIL EXCESS COAX IN A LOOP. It sets up standing waves on the coax that create a mismatch. Coil it up in a circle wrapped around your thumb and elbow,then twist the loop in a figure eight and flip it back on itself and fasten it with a wire tie. The figure eight flips the field of standing waves 180 degrees out of phase with the other half of the loop and "cancels out" the majority of the standing waves. Just an extra tidbit.
4)Maybe it's not your antennas or coax. Some radios are equipped so that their audio circuit goes through the microphone. This can be checked if you have a disconnectable mic. If you unplug it and your sound cuts out,it's wired through the mic. If you have a bad/loose connection inside the mic plug,at the radio end or at the switch in the mic head,it can affect audio output at the speaker, creating the illusion of bad reception.
5)If you're running heat,depending on the wattage,your coax may have fried/shorted itself due to exceeding the maximum rating. Using thicker RG/8U instead of the thinner "normal" sized RG/58U will alleviate the penchant for shorting,but it will not affect XMIT or RCV,except that a better coax(shielding contained within)aids in ensuring that more of the signal,incoming or outgoing,makes it to it's destination and it'll handle more power.
6)And last but not least,it could be your audio chip/circuit inside the radio,again creating the illusion of bad reception. Try all I've suggested FIRST,if it results in no change,I'd suggest consulting a technician of good repute. Your chip may have a loose solder joint or be close to kicking due to vibration.
As for a question of what KIND of antenna to put on your truck,it's buyers choice. Longer lengths of antenna tend to do better. This is however C.B. and they're not designed to communicate more than five miles at best,so don't expect much when transmitting the allowed four watts or receiving over three miles.
I wouldn't advise if I didn't design my own antennas for use in the freeband space above 40 channels to talk skip. I am not a tech but, I think I've enough experience in antenna design to know a few things. I am also a driver of 12 years to know the environment of a truck to know these radios/accessories get beat. At best maybe one of my suggestions will help. At worst you'll be taking it to a tech anyway. I hope I have been helpful.
Kenny(PJ)
There's 2 good CB shops I've found... they're not close at all to eachother... but... the CB shop at the TTT (truck stop) in Tucson, AZ, and the Transformer CB Shop that's by the T/A in Macon, GA. Not the other guy in the newer building, he's a rip-off and con-artist. Those 2 are honest, set you up right, and won't give you no problems. They can set you up - stop by if you're in their area's.
Worth the stop.
Worth the stop.