Cobra 75 WX ST Install & CB Interference With HIDs.

Here's my CB install. I choose the 75 WX ST cause I can remove it when not in use. Plan on getting a HAM radio too so I don’t want clutter in the cab.


The parts I used:

-Cobra WX ST
-Firestik 4ft Firefly FL-4
-Firestik 18ft Coax w/ FireRing

$45 MU8R18 18-Foot Single Antenna Coaxial Cable

MU8R18
-Firestik K4A Stud Mount
-Firestik K1A Quick Disconnect
-5 Pin Female Plug
-5 Pin Male Panel Jack
-1ft Mic Cable
-ASTATIC PDC2 SWR/Power Meter


Here’s what the 75 WX ST looks like right out the box (note the connectors for the handset & remote unit):



Here’s what it looks like after I did some soldering. I reversed the connectors so now the female connector is on the handset cable instead of on the remote unit as it originally was.



Made an extension for the mic & mounted it in one of my accessory covers.



This is why I reversed the connectors on the mic.



I forgot to take pics but I mounted the remote unit behind the ash tray & wired it directly to my ignition switch. I ran the coax cable along the top of the frame covered with wire loom next to an exisiting wire harness & ran it in the cab under my front seat. I ran it through an existing grommet.



Here’s where the handset plugs in.



And when not in use I unplug the handset & remove the antenna.


Antenna & quick disconnect mounted on my bed bar.





I got good SWR readings as is without tuning the antenna considering it's mounted on a bed bar. Without tuning I got 1.5 on ch1 & 1.8 on ch 40. After tuning I could only get it down to 1.4 on ch1 & 1.6 on ch 40.

 

Interference with HIDs

I'm happy with the CB & it works great on the trails. Around town I can sometime pick up people pretty far away. That is until I turn on my HIDs. With my HIDs on I get crazy interference. I have to turn the squelch up so high that I can't pick up anyone unless they are right next to me.

After researching this I learned that the interference is not EMI, it's RFI. Some say they even get interference on some weak FM channels with their HIDs, I never got any interference on my stereo from my HIDs though.

Because it's RFI noise filters on the power line & connecting directly to the battery won't fix this. Found out that it's the circuitry of the cheapo HID ballasts that causes this. Some say that the newer slim ballasts with "digital" circuity helps but I found cases where people have tried them & it made no difference.

Found out that the only way to fix this (other than shielding the ballasts some how, not sure if that even works) is to go with OEM ballasts. After all you get what you pat for. Also heard D1S/D1R systems are a lot better for cutting out RFI. Since I'm planning on getting a HAM radio later, I had to fix this.

So I got lucky & got some Philips D1S/D1R ballasts for $30 each brand spanking new. These come on Cadillac XLRs so finding the connectors was pretty damn hard but I eventually found them. To my surprise each plug has two large ferrite cores. I'm also using D1 to D2 Valeo ignitors from a Volvo. I paid more for each of these used than I got each ballast for!


Here's my last HID setup. Hella style clone ballasts from ebay with AMP connectors, D2 plug, & Philips Ultinon 85122CX D2S w/ Casper shields.



My Casper shields are an older style that just used a guide pin to position the lamp.



I punched out the pins, theaded the holes, & machined down some screws so I can now screw the lamps onto the Casper shields. Also had some new Philips 85126+ D2Rs that I never used so it was time to swap them in.



My new setup installed.




Well they were right, now I get absolutely no interference on my CB with the HIDs turned on now. Not even the slightest hint of noise when turning them on. Also no more electrical whine from the ballasts when they first start up, which was no big deal anyway.

Well worth changing my setup & I would of done it even if I didn't get such a great deal on the ballast. Can't believe I waited so long to use these 85126+ D2Rs. The color tint on them are so much nicer.

 

So your hids r give ur cb interference.... hmmm, maybe try running a ground wire from antenna to frame?

I like ur ug mount, gonna have to show me how or help me that looks so clean!

 

It's radio frequency interference picked up by the antenna from the ballasts. So power noise filters, grounds, direct connections to the battery, etc won't work.

I updated the second post with my fix, an expensive one but should have been even more expensive if I didn't get lucky.

Damn cheap HID ballasts, you get what you pay for.

 

clean install!

 

Dude I was trippin till I read u added to 2nd post. I hate my weak stock headlights....nice job man!

 

Nice work!

Any more details the extension cable you made (connector types, cable types...where you got em)? I'd like to use your method on my second gen.

 

here is how i did my cobra install w/ the help of another member

i did get some noise when i had my hid's on, but mine was a ground issue

 

Thank you

For the extension, I got the cable & connectors from Redman. They have free shipping so total came out less then everyone else. Everything is on this page: http://redmancb.com/Microphones.html

If you need help with anything let me know, I'd be glad to help.

 

Thanks!! Juding by the pics, I would need:

1 - 5 Pin Mic Cord Plug
1 - 5 Pin Panel Jack
A few feet of belden 6 conduit 5 wire cable

 

Yup, you got it. To add, that conduit is 5 wire plus the shielding. The cable for the mic is a 5 pin but really only uses 4 & the 5th pin is ground which is connected to the shielding. I did the same with my extension so I just cut the ends off the extra wire.

If you only need a short extension (10") you can get a preassembled cable with the male panel jack on one end for $6.50 on ebay. The seller is actually Redman. In my case I would still had to unsolder one end to get through the accessory cover & needed longer length so I just built it myself. http://cgi.ebay.com/New-Cb-Ham-5-Pi...861?pt=LH_DefaultDomain_0&hash=item19bbee7ef5

Redman could probably build you custom lengths if you wanted. If you can solder then it's pretty easy & I would just save the money & do it yourself.

 

Awesome, thanks so much! I'm pretty good with the soldering iron, so I'll just build one up. I'll likely need a few feet since I want to mount the remote unit on the back of the center console.

I've got to order my bakflip tonneau before I can look at what options I have for antenna mounting, but I'll let you know how it turns out.

 

Really cool idea with the cobra 75

 

Sub'd for install