[Digmenow]

Yes boys and girls, let's go back to the '70's and talk some Citizens Band (C.B.) radio with a twenty first century twist!

Here's the backstory. Skip if you wish.

• I will be taking the 220 on a thousand-ish mile drive in the coming weeks and then returning along the same path.
• I will be in convoy with another vehicle which will be pulling a 27' camper (caravan/UK).
• Things happen quickly and texting is sometimes too slow to communicate. (REST STOP! REST STOP! NOW! NOW!)
• The other vehicle already has the same C.B. radio so I have purchased an identical Midland 75-822 Portable C.B. radio and a Little Wil magnetic mount C.B. antenna.

How it will look when I use it.

The complete kit, as shipped.

The antenna.

In fact, someone has already posted an internet pic of what I will be using.

As some of you may be aware, there's no space in the front cockpit to install a traditional C.B. radio so this handheld unit solves the problem and can be moved from vehicle to vehicle as desired.

My dilemma is how to route the antenna wire to the outside of the car. I'd like to have the wire come out of the trunk (boot/UK) so it could be mounted on the roof or the trunk lid, whichever works best for me. It would look like one of these setups.

I don't want to run the cable out the window or crimp it in the rear door jamb if I can help it. Keeping in mind that the coax connector is several times the diameter of the cable, where can I run the coax cable from the cabin into the trunk without dismantling the interior, other than removing the rear seat bench? Is there a porthole that I can access?

 

[MikeKerr]

Very cool. I think it is a lot of work to run the cable for a temporary setup. A course of action you may want to consider is running it out the back door, knowing the cable will get crushed, but in the short term should be fine. Throw the antenna away when it fails, which I doubt it will by crushing the cable in the near term.

Don't forget the most important and often overlooked step in installing a mobile CB is tuning the antenna. While a properly tuned antenna will result in strong radio performance, a badly tuned or untuned antenna can result in poor performance and can even damage your radio.

I doubt at close range the tuning is much of a issue, but at distance it may be.

 

[Dave2302]

"Hey good buddy",

You'd be fine if you had my W220, as it has the Ski Bag Option :grin

Don't suppose your car has that ?????

SWR Meter needed to set up the Antenna :wink

"Keep an eye out for them Bears, make sure it's clean and green ..............

Catch you on the flip flop"

"West Kingsdown Worzel Out" :devil

 

[Digmenow]

Thanks, guys. No ski bag option, sadly. On the plus side, the driver of the other vehicle has an SWR meter and we'll be tuning and testing it in advance. In fact, I'm pretty sure that I have still have my own meter as well but it WAS the 70's so... :grin

I wonder just how badly the coax would be crimped by the door. Is it like a bank vault?

 

[MikeKerr]

"coax would be crimped by the door. Is it like a bank vault? "

I think the coax will be fine. The outside wire (ground) of the coax is typically a spider mesh, the inside lead is typically solid copper, with a nice plastic insulator separating them. I would not hesitate for a minute having the soft close door and the rubber weather stripping push down on the antenna cable, should last hundreds of open and close cycles prior to cable damage.

 

[wallyp]

I have four hand-held "Family Service Radios", which normally have a couple of miles range. That would be my first try - usable in or out of the vehicles (useful at rest stops, parks, restaurants, etc.), fit in a pocket.

Haven't tried them in the Mercedes, with the iron-containing glass, though.

You might want to see what the CB range is with the antenna sitting inside the car, say on the rear shelf.

 

[Digmenow]

I have four hand-held "Family Service Radios", which normally have a couple of miles range. That would be my first try - usable in or out of the vehicles (useful at rest stops, parks, restaurants, etc.), fit in a pocket.

Haven't tried them in the Mercedes, with the iron-containing glass, though.

You might want to see what the CB range is with the antenna sitting inside the car, say on the rear shelf.

That's an interesting thought but I'm not sure how to tune it. It is supposed to be grounded, however although how you ground a mag mount antenna through M-B trunk lid paint is a question that I can't really answer. We looked into the FRS's but he already had the CB so I went that route as well. Also, battery life was a concern as we will be on the road about 9 hours each day with the radios constantly on.

 

[pinkster]

Run the cable under the rear seat and follow the factory cables, plenty of room on the left side.

 

[Dave2302]

Hi,

Correct me if I'm wrong but it was always my understanding that a Mag mount is Grounded to the Radio via the Outer Woven wire of the Co - Ax Cable :wink

Re Battery Life .................

You had a Cig Lighter Charger in that kit didn't you ??

I'd keep it plugged in whilst on the move :wink

Cheers Dave

 

[Digmenow]

Run the cable under the rear seat and follow the factory cables, plenty of room on the left side.

Sweet! Thanks.

Hi,

Correct me if I'm wrong but it was always my understanding that a Mag mount is Grounded to the Radio via the Outer Woven wire of the Co - Ax Cable :wink

Re Battery Life .................

You had a Cig Lighter Charger in that kit didn't you ??

I'd keep it plugged in whilst on the move :wink

Cheers Dave

Now that you say it, the grounding makes sense but they make such a big deal about it in the videos that I wasn't sure. As for the battery life, that was referring to the FRS radios that Wally mentioned. I believe they mostly have to be recharged in their cradle. I am not aware (didn't look to hard) of a car charging option.

Thanks for all the help, guys. I hope to install it this weekend. Pics will be included.

 

[plinker17722]

This is the best copy i have had from the USA --- come on good buddy bring it on back, anyone for a rig check 10-4 My Cobra 148 GTX could do with a good work out. First day i had mine i picked up truckers on the freeway in the USA with indoor moomraker mag mount on a buiscuit tin . And not long after i had a visit from Telecom for giving next door TVI All good days back then, and the pioneers for mobile phones

 

[Ex-Fed]

You dont really need external antenna for your use. Running together I shouldnt think you would be any more than 1/2 mile or so apart. Use the "rubber ducky" antenna on your unit. At 27 Mhz. the infrared coating ( if present ) would be a non factor.
If you REALLY wanted extrernal antenna, then the best of all mounting locations would be center of the roof ( impractical, coax thru sunroof or across roof and into door ). Then back edge of the roof in front of the "sharkfin" ( bit better, could run coax thru channel around back glass and gain entry thru same port that "Sharkfin" uses ) Decent compromise would be a trunk lip mount on back edge of trunk nearest rear windshield. The coax would curl around lip of trunk, thru 1 weather strip and into trunk area. Getting from trunk area to cabin is a bit complicated but fairly easy. See the parcel shelf section of this .. http://www.benzworld.org/forums/w220-s-class/2000609-less-than-20-usd-gps-antenna.html#post8675617

Trunk lid mount could also be permanent if desired. Or removed after needed with a bit of touch up where the set screws cinched down.

These antennas do not need a "ground" per se, the radio power leads provide a DC ground for the working voltage. They do need a "ground plane" to work against. WHich is why that trunk lip mount in the pic has 2 pointed set screws. Both for physically mounting the antenna and provide an RF path to the trunk lid so it acts as a ground plane. A ground plane is merely a flat or nearly so, conductive surface that acts as the missing leg of a half wave dipole antenna. Mobile CB antennas, for the most part, are end fed 1/4 wave length radiators, they need that ground plane to tune and radiate properly. I.E. omnidirectional radiation/reception at a low enough angle to be useful.

Ham radio operator call sign KB7IJ since 1976 and I do tend to ramble, sorry

 

[Digmenow]

You dont really need external antenna for your use. Running together I shouldnt think you would be any more than 1/2 mile or so apart. Use the "rubber ducky" antenna on your unit. At 27 Mhz. the infrared coating ( if present ) would be a non factor.
If you REALLY wanted extrernal antenna, then the best of all mounting locations would be center of the roof ( impractical, coax thru sunroof or across roof and into door ). Then back edge of the roof in front of the "sharkfin" ( bit better, could run coax thru channel around back glass and gain entry thru same port that "Sharkfin" uses ) Decent compromise would be a trunk lip mount on back edge of trunk nearest rear windshield. The coax would curl around lip of trunk, thru 1 weather strip and into trunk area. Getting from trunk area to cabin is a bit complicated but fairly easy. See the parcel shelf section of this .. http://www.benzworld.org/forums/w220-s-class/2000609-less-than-20-usd-gps-antenna.html#post8675617

Trunk lid mount could also be permanent if desired. Or removed after needed with a bit of touch up where the set screws cinched down.

These antennas do not need a "ground" per se, the radio power leads provide a DC ground for the working voltage. They do need a "ground plane" to work against. WHich is why that trunk lip mount in the pic has 2 pointed set screws. Both for physically mounting the antenna and provide an RF path to the trunk lid so it acts as a ground plane. A ground plane is merely a flat or nearly so, conductive surface that acts as the missing leg of a half wave dipole antenna. Mobile CB antennas, for the most part, are end fed 1/4 wave length radiators, they need that ground plane to tune and radiate properly. I.E. omnidirectional radiation/reception at a low enough angle to be useful.

Ham radio operator call sign KB7IJ since 1976 and I do tend to ramble, sorry

There were so many negative comments about the rubber ducky not getting out very far when used inside of the car. People reported not being able to transmit 10 car lengths in stopped traffic and there's a possibility of a mile or so separation so I wanted the external whip. I had a set screw trunk mount back in the day but I will be moving the setup from the 220 to the Silverado from time to time (unless I use the old 6 foot whip that came on the truck with the nonfunctioning CB!). Regardless, I have the mag mount and will go ahead with that. Can't bear to expose the car to even the smallest point of attack for tinworms.

 

[Ex-Fed]

Very well, Mag Mount it is. Top of roof, raise back edge of sunroof ( if so equpped ) just enough to get coax connector thru, lower sunroof till barely open and coax isnt crushed. operate away. Easily taken down when stopped for the night. Removes temptation from the heart of some cupcake wandering around parking lot late at night. No mars no scars and should work very well in all directions. Be safe.

 

[Skylaw]

Oh, my! You guys are taking me back just over 50 years, to my physics classes in college - and stuff I had to brush up on 25 years ago when I was drafting patent applications.

Don't know whether that made me feel young again, Richard, or just old. But you're right!