Connex 3300 HP Interference Issue

[Fordguy1982]

Hello... Thanks for having me.. I'm having an issue with my radio.. I acquired an Connex 3300 HP... I took it today and had it gone over at my closest CB shop... ( I was treated awful there, The owner was VERY rude! I will never go there again!!) Anyways, I Installed a new Francis CB 22 3' antenna today and a new 18' RG 58A coax.. I have the power wired in to my fuse box under the dash of my 1999 F250 Diesel.. When the truck isn't running, I can have my RF gain 3/4's of the way up or all the way and its fine, Normal static... But when I start the truck with the RF gain up that high I get feedback/interference... And my meter is almost all the way up to the max.. No matter how much I have the squelch turned up, The feedback it's still there.. When I lower my FR gain when the trucks running it clears up.. But then I can't hear anyone.... I guess my question is, Where would be the best place to tap into to power my CB? That wouldn't interfere and cause this issue? The CB shop said everything seemed fine with the radio, So nothing was adjusted.. (He did however spin the antenna jack on my CB broke the wire inside and continued to blame me for it.. Also charged me to fix his mess up!!) Thanks for any idea or recommendation you may have..

[MDYoungblood]

There is a couple things you can try. First wire the radio straight to the battery eliminating any interference from the fuse box. Heater/AC fan, wipers, turn signals, etc. all go through the fuse box and cause noise. Next is to determine what the noise is and where it's coming from. A whine that speeds up with engine RPM is most likely the alternator. Clicking that speeds up with engine RPM is injectors. A constant whine is the electronic fuel pump. The list can go on. Try these couple of things first then get back to us.

3's

Greg

[Fordguy1982]

I ran the power wire directly to the battery. It still has the noise.. It gets louder when I give it throttle..

[MDYoungblood]

Next would be to see if it's coming through the power leads or the antenna. A simple test is to turn the volume up a tad more than usual and disconnect the antenna from the back of the radio,, don't key the mic, if you still hear the whine then it is the power leads, if it's louder with the antenna connected than it's being transmitted.

3's

Greg

[Fordguy1982]

Message from moderator Bozo

three consecutive posts into one

Here's a video of my issue...

YOUTUBE_ADMIN

YOUTUBE_ADMIN

I'm uploading another to YouTube that shows what it does with the truck running..

YOUTUBE_ADMIN

YOUTUBE_ADMIN

[MDYoungblood]

In the first video all I hear (see) is normal static which is normal on your radio (General Lee), the second video I do hear some injector noise which is an early Ford diesel trait, you turned the RF gain down too far to really see how bad it is. I would guess no one answered your callout because no one was close enough to break the noise level (not sure where you live), could spin the dial to find some activity. The static could be a locality thing, does it do that every place you have driven (stopped with the engine off). Last the antenna being 3ft is short, limited to it's bandwidth, a longer antenna will pick up more signal.
A couple questions.
How is the antenna mounted and how is the coax ran? Did you adjust the SWR on the antenna?
The radio mount, is it attached to just the plastic dash or do the screws go into the metal dash frame?
Was the radio purchased new or is it a used/second owner? Other than the frequency mod has there been any other mods?

3's

Greg

[51]

mobile noise can be a headache to solve and cure. first you need to make your power wire run as direct and as short as possible straight to the battery. keep all power leads as far away as possible from all electrical systems in the vehicle. ie ignition wires etc, computer, injectors, fuel pumps, etc. ANYTHING thats electrical. second, make sure you have a solid and clean chassis ground for dc and rf. this is just the beginning, there are MANY other things that need to be done. also when its all said and done, there is a chance that you have a noisy vehicle that will not and cannot be quieted down. if you google it, there is a list of notoriously electrically noisy cars and trucks that are not radio friendly. also like MDY said it would kinda help to know how the noise is entering the system. disconnect the antenna, does the noise stop or no? good luck. let us know your progress, and for more help.

[Russ]

I had a ford back in the days....did the same thing....the fuel pump was fords issue as I recall...also, you need to install a noise filter that attaches to both positive and negative wires between radio and battery...this is a must for all mobile installations...gets rid of any engine whine...best of luck!!