Sending issues with my uniden/4 ft firestik combo

[JAXjeremy]

Hi everyone. I've got a small uniden CB in my rig connected to a 4 ft firestik antenna by way of a some high quality coax. The CB is direct wired to the battery and I tuned the antenna with my SWR meter and it's set correctly. Anyway, the CB receives just fine, but when I transmit I've got problems and folks I'm trail riding with can barely hear me.

I've checked the basics, antenna ground, kinks in the coax, but can find anything that stands out. The unit is relatively new, but maybe there's a problem with the mic. Unable to post pics to show my setup, so before I toss it and get something else, wanted to check with you guys to see if I'm overlooking anything. Thanks.

[Namvet69]

Are you showing any kind of forward swing or movement on the radio meter ?

[MDYoungblood]

I'm guessing but this is the setup your running; [Please login or register to view this link] , glad to hear you got the SWR problem figured out. The problem could be the mic or just the radio needs a little tweaking to make it modulate better. The little Uniden 520XL, sice there is no warranty on it now, open the speaker side and look for a diode marked D14, clip one side and lift it so it is not making contact, put the cover back on and try that. It should sound 100% better unless like you said there is a problem with the microphone.

3's

Greg

[JAXjeremy]

Are you showing any kind of forward swing or movement on the radio meter ?

Haven't checked the SWR in a while. This is primarily and offroad vehicle and doesn't get driven a whole lot. That is on my list for this weekend.

[JAXjeremy]

I'm guessing but this is the setup your running; , glad to hear you got the SWR problem figured out. The problem could be the mic or just the radio needs a little tweaking to make it modulate better. The little Uniden 520XL, sice there is no warranty on it now, open the speaker side and look for a diode marked D14, clip one side and lift it so it is not making contact, put the cover back on and try that. It should sound 100% better unless like you said there is a problem with the microphone.

3's

Greg

That's my setup..thought I had posted here a while back, yeah the SWR was good at the time. So you're suggesting clipping this D14 diode?? I can definitely give that a shot. Can't imagine it's the mic, but I guess anything is possible.

[Bobcat]

This may sound weird....but I am just trying to "cover the base".
When you key and they can't hear you.... ask them to take a look at their S meter next time and see what the needle does when you key.

I have had people in close proximity to my antenna before and, when the keyed up, the needle took a jump WAY high on the scale. I think that, what was happening was that they were hitting MY receiver so hard they were overloading my front end..... sort of like compressing it.... squashing all the modulation out because it was driving the incoming signal to the rails.... so when it demodulates.. you don't get much apparent audio.

It's just a thought.....

[JAXjeremy]

Thanks for the suggestion Bobcat, I can tell you when we tested it we were pretty close together. Again, I could hear him fine, but my was not coming through very good on his side..don't recall what sort of CB he had..I've got a neighbor that has a Cobra 29 we can test with.

[MDYoungblood]

I agree that it is possible for your radio to overload the receive of another, since your neighbor has a Cobra radio, once to check that it is not that ask to borrow his microphone and try, the wiring (4pin) is the same on both radios.

3's

Greg

[jessejamesdallas]

Could just be a damaged Mic...Seeing how this is on a off road vehicle that doesn't get used much...moisture from just changing weather could have damaged it...

IF SWR checks out OK, try a different Mic. If this is the uniden 520xl, any Cobra 4-pin Mic will work with it...I have a 520 also, and personally I think those little factory Mic's that come with that radio are POS to start with.

[battyice]

Are you still using the stock Uniden mic?

There is something different about the factory mics on those little Uniden's. I tried a known-good mic off a Cobra on a Uniden 520Xl and everyone said they could barely hear me. I switched back to the factory mic and everyone said I sounded great.

[JAXjeremy]

I'm using the factory mic. This weekend, I went back and double-checked everything, antenna mount, ground, and coax connections, SWR. Turns out the problem was where the coax attaches to the radio. I noticed there was a lot of thread showing and realized the collar wasn't screwed the whole way down. Basically I had a bad connection to the antenna. Anyway, I tested with my neighbor and his Cobra 29 all is good.

[443 Arizona]

i knew i could fix it,,haha

[Bobcat]

Excellent! I'm glad to hear that you got it going .... AND that it was simple and didn't cost anything makes it even better!!!!

[ Post made via Linux Laptop ]

[Magnetics]

Hello Friend. Check the voltage of your battery, both on the terminal and on the radio. Try to use the braided wire to avoid radio frequency interactions on the power cord.

[Msppiguy]

I'm guessing but this is the setup your running; [Please login or register to view this link] , glad to hear you got the SWR problem figured out. The problem could be the mic or just the radio needs a little tweaking to make it modulate better. The little Uniden 520XL, sice there is no warranty on it now, open the speaker side and look for a diode marked D14, clip one side and lift it so it is not making contact, put the cover back on and try that. It should sound 100% better unless like you said there is a problem with the microphone.

3's

Greg

I am new here. So what does clipping that diode do ? Thanks

[MDYoungblood]

Clipping the diode will disable the AMC (Automatic Modulation Control) in the radio. Using a stock mic it will sound a lot better, if a power mic is used adjust the gain so it doesn't over modulate.

3's

Greg