CB Squeal!!!

[jaster]

I recently installed the Starcom system on my 06 AE. I am adding a CB to the system and a push-to-talk button. I am able to hear everything fine, but when I try to transmit I get a screeching sound in my headset as well as whoever is close enough to receive it. This does this with the push-to-talk as well as the VOX system. It does it whether it's hooked into the bike's power or operating off batteries. It does it whether the bike is running or not. It does it whether the CB and Starcom are close together or further apart.

Anyone have any idea what the problem might be?

Thanks,

Jaster

 

[Badcat]

I recently installed the Starcom system on my 06 AE. I am adding a CB to the system and a push-to-talk button. I am able to hear everything fine, but when I try to transmit I get a screeching sound in my headset as well as whoever is close enough to receive it. This does this with the push-to-talk as well as the VOX system. It does it whether it's hooked into the bike's power or operating off batteries. It does it whether the bike is running or not. It does it whether the CB and Starcom are close together or further apart.
Anyone have any idea what the problem might be?

Thanks,

Jaster

More than likely the rf from the radio is getting into the wiring. The grounds have to be very secure. I use an rf choke that the audio cable to the cb wraps around. It cured my systems squeel problem.

 

[dcarver]

I recently installed the Starcom system on my 06 AE. I am adding a CB to the system and a push-to-talk button. I am able to hear everything fine, but when I try to transmit I get a screeching sound in my headset as well as whoever is close enough to receive it. This does this with the push-to-talk as well as the VOX system. It does it whether it's hooked into the bike's power or operating off batteries. It does it whether the bike is running or not. It does it whether the CB and Starcom are close together or further apart.
Anyone have any idea what the problem might be?

Thanks,

Jaster

More than likely the rf from the radio is getting into the wiring. The grounds have to be very secure. I use an rf choke that the audio cable to the cb wraps around. It cured my systems squeel problem.

Badcat, noticed you only had one post back, but don't have any good info for you.. don't run CB through SC.. so BUMP, and have you tried contacting Jeff at Sport Bike Effects?

 

[jaster]

More than likely the rf from the radio is getting into the wiring. The grounds have to be very secure. I use an rf choke that the audio cable to the cb wraps around. It cured my systems squeel problem.

Thanks for the info Badcat, I will be checking out my local Radio Shack.

 

[jaster]

Badcat, noticed you only had one post back, but don't have any good info for you.. don't run CB through SC.. so BUMP, and have you tried contacting Jeff at Sport Bike Effects?

Jeff suggested I ask here on the forum, he has limited experience with CB's. If I can't run the CB then I've made a bad choice in the StarCom. The group I ride with all run CB's.

The StarCom lists several CB's, mine being one of them, so I would think there is a cure for this. I will be giving the RF choke a shot.

 

[FJRandy]

You didn't say what model CB you're using. Could be a number of things going on, but it sounds to me like a wiring mismatch. From the info you already posted about the CB being battery powered and still doing it, an RF choke will do nothing to fix it.

Look at the Starcom wiring and MAKE SURE it's compatible with the CB you're using. Second step (if possible) is to swap out another identical radio to see if the problem still exists.

You could also try the CB with the starcom unplugged to see if you still get a sqeal. At least you'll be headed in the right direction by eliminating one possible cause.

Bottom line, somehow somewhere through the wiring, your speaker is joining with your mic when you push to talk. They should isolate from each other on PTT. There are other things that cause the same problem, but this seems to be the most common.

 

[jaster]

You didn't say what model CB you're using. Could be a number of things going on, but it sounds to me like a wiring mismatch. From the info you already posted about the CB being battery powered and still doing it, an RF choke will do nothing to fix it.Look at the Starcom wiring and MAKE SURE it's compatible with the CB you're using. Second step (if possible) is to swap out another identical radio to see if the problem still exists.

You could also try the CB with the starcom unplugged to see if you still get a sqeal. At least you'll be headed in the right direction by eliminating one possible cause.

Bottom line, somehow somewhere through the wiring, your speaker is joining with your mic when you push to talk. They should isolate from each other on PTT. There are other things that cause the same problem, but this seems to be the most common.

The CB I'm using is a Cobra HH38WXSI handheld unit. All wiring comes from StarCom and was specified for this radio. I have also tried a handheld Maxon brand that uses the same connections. It squealed also. The radio works fine when unplugged from the StarCom. I can disconnect the PTT and use the VOX to activate and I get the same result.

Thanks FJRandy for the feedback, I appreciate you trying to help out the electronic illiterate. :blink:

 

[OrangevaleFJR]

You got good feedback. I would ask one more question. Does your radio have a simplex and duplex setting? If you are transmitting in duplex mode, the receiver stays on and in a highly charged electronic environment (like near a running engine) you'd like get nasty feedback.

(I don't know much about CB's, so if CB's don't have this selection, nevermind.)

 

[FJRandy]

O-V, I've never seen a CB radio that could transmit in duplex mode for the simple fact of the squealing problem. This is why the PTT switch (or onboard VOX) is supposed to cut out the speaker when transmitting, and cut out the mic when receiving. I know a CB can be modified to do this (called "talkback") but it involves a special circuit. Many times when a handheld mic on a std size CB shits the bed (as they say) it will squeal like a stuck pig if the mic is close enough to the speaker. The failing contacts inside the mic's PTT switch allow the mic and spkr to operate at the same time.

Jaster, return the Starcom and all the wiring. If it IS, in fact the proper wiring for the Cobra, the only last resort is to try it with the Starcom volume control set just low enough to hear it. If it STILL squeals with the volume barely up, it either really isn't compatible or there's definitely something amiss internally (or externally) in the Starcom wiring. Just for giggles, try to unplug only the mic from the helmet, leaving the speakers intact and plugged in. Also, are you sure the VOX sensitivity isn't too high? The VOX on Starcoms might be duplex. Just a thought. See what happens.

FWIW, I'm running a Midland 75-822 handheld CB through my Autocom and have never had a squeal problem. Now engine noise......that's a whole 'nuther thing! One of these days I'll get out there and play around with it. Best part is I can't hear the noise with my earplugs in.

 

[mindtrip]

One other thought--could it be that the connections inside the DIN plug are inadequate?

I only ask because I just got my StarCom delivered last night, and after installing it spent ~3 hours trouble-shooting it. My radar detector can't be heard throught the isolated cable, but works just fine through a non-isolated lead; the isolated lead for my GPS audio was acting 'funny', sometimes working and sometimes not; and the PTT button was also only working intermittantly for my FRS radio. I never got the radar detector working, BUT I found the lead to the GPS was just a bad connection; fiddling with the plug where it goes to the GPS jack seems to make it work. Further, I could only get the PTT working consistently when I took a small screwdriver and pushed the DIN pins in the radio and PTT plugs VERY, VERY SLIGHTLY toward the outer circumference of the plug. JUST A LITTLE BIT, or you risk breaking the pins or making them not mate correctly with the plug in the Starcom. However, pushing them out just a bit significantly improved the connection when those cables were plugged into the StarCom, and now the radio works just fine, every time.

Now, since I have absolutely no idea what your problem is precisely, I don't know if this will help you, but it worked for me.

 

[bogey]

I had exactly the same problem as you've described with exactly the same handheld cb. I tried all the above fixes to no avail. What did work is not using the small rubber antenna and mounting a better one with a relatively long cable. i went with a firestik (3 footer) and I believe it was either a 12 foot or 18 foot cable - can't remember!! That fixed the squeal but I still need to tweak the system as I can't seem to listen to my satellite radio and have the cb on at the same time. Not sure if it is the squelch control or what. I've tried both the vox and the push to talk - prefer the push to talk personally unless I'm riding two up. I have also used the starcom with a small cobra radio (one of those two way radios you can pick up pretty inexpensively) and just used it on an 8 day trip from Arizona to Toronto and that worked quite well.

I'll be using the cb again in another couple of weeks on another ride where the others prefer cbs. I hope to have all those squelch issues worked out before then. Hope this helps as it was frustrating trying to get rid of that annoying squeal. Bogey

 

[rxfjr]

I also am very interested in this topic. I have successfully run the Starcom1 with a Motorola Talkabout FRS with no problems. Have a big trip planned with some friends with a Harley touring bike that has a built-in CB. I did some research on the best hand-held to use and found a real lack of data. I ended up buying a Midland 75-822 hand-held unit and got the cable that was recommended, a CAB-02. We tested the unit out and got the same squeal that you described. It occurred using PTT and VOX. I unplug the CAB-02 that connects the CB to the Starcom1 and use the CB by itself and get no squeal.

The only way I have been able to mute (not completely but less squeal feedback) has been to switch a H/L button on the CB to the LOW setting. Haven't figured out what that button is. It isn't explained in the instruction manual or on the website. I get the signal from the Harley perfectly, I just get the squeal when I transmit a signal with PTT or VOX. The squeal comes thru on the Harley end also.

I am not sure how or why an antenna change would change or fix this problem.

Thanks in advance for any assistance.

Greg

(a non-techie) :blink:

 

[Badcat]

The H/L switch on low reduces the RF output power of the CB. The reason the squeal goes away in the low setting is there isn't enough RF entering the system to cause it. RF chokes and proper grounding are the only way you will get rid of the unwanted noise. (Doesn't work on spouse)

 

[FJRandy]

The only way I have been able to mute (not completely but less squeal feedback) has been to switch a H/L button on the CB to the LOW setting. Haven't figured out what that button is. It isn't explained in the instruction manual or on the website. I get the signal from the Harley perfectly, I just get the squeal when I transmit a signal with PTT or VOX. The squeal comes thru on the Harley end also. I am not sure how or why an antenna change would change or fix this problem.

Thanks in advance for any assistance.

Greg

(a non-techie) :blink:

Good choice on the radio, Greg. The H/L stich is for high or low power. That's why the squeal is less on "L".

As far as the above comments on using an outboard antenna, I believe the problem IS in the Starcom cable. Especially if the problem is mostly gone with an antenna mounted in the rear somewhere. Sounds to me like the CB is transmitting into the Starcom adapter cable.

Remember folks......grounded CB antennas require a 9' minimum cable (12' is optimum) grounded to the frame. Non groundplane antennas MUST use a 17' cable, wrapped in a tight figure "8".

A good rule of tumb for a 2'-3' grounded antenna is to use a 12' cable no matter what.

A 4' grounded antenna can get away a 9' cable and still tune well. Non grounded antennas use the 17 footer.

Jaster, would you like to borrow my spare Midland 75-820 to try? I'm curious myself to know if it only happens with the Cobra.

PM if interested.

Randy

 

[rxfjr]

Ok, RF chokes seem to be a potential fix. Where do you pick one up and how does it attach to the unit or wires?

Greg

ps. An RF filter for the wife? I like it! :yahoo: