View Full Version : SSB Garbage on Only 1 of 3 Antennas

01-13-2014, 01:31 AM
I have 3 Cobra 148 GTL radios. One set up as a base station with an Antron 99 18 foot antenna, and one in each car. We use them as our mobile comms because I got tired of paying exorbitant amounts of money for cell phones and getting mean phone calls if I was a day late.

Anyway. Both of the mobile 148s use Lil Wil' 36" whip antennas. I bought all radios and antennas brand new. The one in my Dodge Dakota pickup truck works great, even on SSB. If I'm out in my pickup truck I can tune my wife in on the base station just fine and talk all day long with perfect clarity. The SWR reading, using the built-in SWR meter, on both the base station and the one in my Dodge, is 1 or 1.1, sometimes I can barely see the needle move ever so slightly if it's really cold out, but most of the time it just sits at 1. This is useful during daylight hours because talking on USB allows us to tune out a lot of the background noise and talk without covering up people who are talking on the same channel on AM. The one in our Ford Explorer though has slightly higher SWR for some reason, 1.5-2 depending on the temperature, and for the life of me I can NOT tune in that radio on the base station. If my wife is out in the Explorer she can tune in the base station good enough to hear me, but I can not seem to tune her in at all and can just barely understand her on SSB. I've tried swapping radios and putting the one that is normally in my pickup in the Explorer and had the same issue, higher than normal SWR and an inability to tune each other in on SSB. On AM the radio seems to work great and sounds just fine.

I've checked the path I have my coax ran to make sure there aren't any really sharp bends or kinks in it and it all looks fine, so I'm not understanding why I have higher SWR on one antenna than I do on the other when my method of install is identical between both vehicles, I used identical brand new radios and identical brand new antennas. I have my radios dash mounted (the Dodge Dakota is really small and the Explorer has a huge console, so mounting them under the dash in either vehicle would be really awkward) and the antenna coax runs around then under the dash, and through the rubber bushing where the rest of the wiring harness passes through the firewall, through the body of the vehicle and up through a small opening by the windshield wipers where they don't get bumped by the wipers or the hood, then up the black border on the edge of my windshield so it's not visible from inside the vehicle and onto the top center of the roof of both vehicles.

The Explorer has a whole lot more computerized stuff in it and a ton more wires in the wiring harness, could that contribute to a high SWR maybe via electrical interference? Could that affect my ability to tune her in when we try to use SSB? I'm really at a loss for why that particular antenna has higher SWR and is preventing me from tuning in SSB broadcasts coming off it.

01-14-2014, 06:11 PM
if you have the newer front mic 148's that's probably the problem . they're not made with the same quality of components as the older side mic versions and they are famous for being crappy on SSB . i also wouldn't trust the built in swr meter on any cb/export radio , use a external one with only coax between the meter and the antenna , no amps etc. .

the caveman
01-14-2014, 06:36 PM
I agree with booty.

01-14-2014, 06:48 PM
All I can think of Is the ground plane area are different between the two vehicles. I would have thought the Exploder would have had a better ground plane, and lower SWR. .Pickups can be hard to tune In my experience.

Gordon Gekko
01-15-2014, 03:43 AM
Get an external swr meter as Booty suggested. Get your true reading. Then adjust the whip as necessary for proper swr. It is possible you may have to trim the whip to achieve optimum swr.

Your other option is to completely ditch the shitty Wilson antenna altogethet and get yourself a Sirio P-5000 .

Anyway both suggestions will fix your swr problem however that may not fix the ssb problem your having. The radio itself may be out of alignment. First fix your antennas, if that doesn't do it, have a tech check the radio. If the radio is still new, maybe return it for a new one.

02-12-2014, 09:09 AM
If the explorer has sat. nav or satilite radio that may be your issue. We have a hard time getting decent swr on GM products that have those features. Fords dont seem to be as bad though.

02-12-2014, 06:07 PM
Have you tried using your multi-reader and get an olms. reading to see if there is a chance for a loose ground. Wiggle the coax joints a little and test while doing this. Try to see if the car will show a ground connection also using olms reading. I would also use an swr meter and not the one in the radio. I woulld like to hear from you on the birthday of the radio's to see if the radio's are the same. From personial experence little will's create wind noise at speed for me. I am having trouble with my Dodge Ram in that I could not get a solid ground reading so I installed grounding points. I transport canoes and the above the cab rack I can not get a wilson trucker model to work. No ground is the problem so far. I went to a 102" steel whip and became a Hi-Teck Red Neck from the hill of Rocky-top Tennessee. Carry on gentle men my Navy has your back.
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