antenna warning light

[snelson0990]

i have a cobra 29 ltd classic that the antenna warning light is on. the radio and coax are out of my old rig but antenna and mount are new. coax is kb super mini 8. antenna is firestik 2, mount is wilson gumdrop. radio wired directly to battery. radio also had a swing mod done when it was new and i never had this problem in my old rig. now i go to key up and my warning light comes on for the antenna. i do have pretty decent recieve signal. wondering what would cause this issue butalso dont want to risk frying my radio. would love any possible advice. my truck is a 97 f150 extented cab

[231]

Welcome to the forum.

First of all you didn't mention what your standing wave match is (aka 'SWR') which means you either didn't tune the antenna or don't know? The antenna warning light is to let you know the antenna isn't tuned properly. If I recall, that radio has a built in SWR meter but most of us don't trust them. We invest in an external SWR meter to tune the antenna for minimum SWR.

That being said, if in fact the antenna is tuned properly (minimum SWR), it's not uncommon for the antenna warning light to be out of adjustment. But first things first...make sure the antenna is properly tuned for the installation. All of them vary some where they need to be tuned.

Good luck.

231

[snelson0990]

when in calibrate mode do i tune it to where it says 'cal' on my built in meter? could be another possibility that i am doing it completely wrong

[231]

when in calibrate mode do i tune it to where it says 'cal' on my built in meter? could be another possibility that i am doing it completely wrong

Yes, key the mic and turn the knob until the meter meets the 'Cal'. Then turn it to SWR and key the mic...the meter will hopefully display what the radio is seeing. This is what most of us don't trust as Cobra (and other) meters don't have a good reputation of being accurate. Nevertheless, ideally the SWR (standing wave ratio) will be below 2:1. Higher than that can damage the final transistors in the radio on some models...not just reduce your transmitting ability (significantly in some cases).

Judging by your response you haven't taken the time to tune your antenna which is a critical part in transmitting. We have a whole section geared toward new radio folks HERE. I'd advise you take some time and read through some of the threads...especially about mobile antennas 101. Without question the antenna is literally 90% of the overall function of the system. Hearing well doesn't mean you will transmit well. And just because you hear someone doesn't mean they will hear you. All you can do is make sure your gear is performing optimally...and adjusting the SWR is part of that.

Good luck.

231

[snelson0990]

tried tuning aproximately an 1/8 inch at a time, could not get standing wave below 3. the final in my radio is not stock either, has been upgraded. wondering if it may be a bad antenna or a bad ground? tried tuning from the screw all the way down to all the way up, was at it for about an hour.

[231]

If the final in the radio isn't stock I'd surely not be trusting the internal SWR meter. And just because the final isn't stock doesn't mean it can handle a bad standing wave. Keep your key ups very short...it won't hurt to listen just talk allot.

Sounds like your counterpoise connection (aka ground) isn't sufficient...but I'd only be guessing. More specific detailed info' on the mount, location, stud type, and mounting hardware would be helpful. Invest in an external SWR meter, too. They aren't that expensive.

231

[snelson0990]

mounted throught the roof via wilson gumdrop mount, towards the rear of the cab in the middle. i may try running a ground this weekend. i havent keyed up much aside from tuning. reason being i dont want to fry my unit. going to look into getting a meter soon too if i cant get the swr down to 2:1 or less. last truck i had it in was around 1.3:1 with almost the exact same setup

[TheCBDoctor]

i have a cobra 29 ltd classic that the antenna warning light is on. the radio and coax are out of my old rig but antenna and mount are new. coax is kb super mini 8. antenna is firestik 2, mount is wilson gumdrop. radio wired directly to battery. radio also had a swing mod done when it was new and i never had this problem in my old rig. now i go to key up and my warning light comes on for the antenna. i do have pretty decent recieve signal. wondering what would cause this issue butalso dont want to risk frying my radio. would love any possible advice. my truck is a 97 f150 extented cab

Good morning snelson0990,

When a Cobra 29 LTD has the audio limiter removed the antenna warning light indicator needs to be adjusted. The SWR meters on the Cobra 29 LTD work well and may not be exact, but are in the ball park. If your radio was made in the Philippines or Taiwan this was not an issue, but any radio made in China must have the SWR "Idiot Light" recalibrated. The potentiometer is the one towards the rear just next to the power plug.

I don't have the schematic in front of me, but I believe it is VR-12. Don't quote me on it because I will have to look it up. Any radio that is made in China has to have the antenna warning indicator adjusted if the radio was "Tuned and Peaked."

I have supplied a link to a radio made in Taiwan from my website. You can see the adjustment just to the left of the power supply jack behind the noise filtering Coil. The audio limiter adjustment VR-4 is in front of it. It is the photo at the bottom left out of the 4 photos taken.

http://thecbdoctor.net/_mgxro ... 10831.html

Respectfully as always

[snelson0990]

i thank the both of you for your help and advice, got it fixed. i had a combination of 2 problems. 1) bad ground plane connection. 2) my brand new firestik was defective. ran the ground and still had insanely high ser( i did buy a meter yesterday). tried my brothers old antenna that he had laying around and my swr dropped to around 1.7:1. antenna warning light is gone now. thank you both very much. i may send this cb to a shop in my area to be peaked out and properly tuned.

[craig_sez]

Another thought to..Are your connections clean and tight...When you mounted the ant in the ant mount did you have the plastic washer between mount and ant on top or bottom..It should be on top between ant and mount..