Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×


Reply
 
Thread Tools Display Modes
 
Old 02-19-2020, 08:33 PM   #1
Bus Nut
 
bigskypc50's Avatar
 
Join Date: Dec 2016
Location: MONTANA
Posts: 471
Year: 1995
Coachwork: AMTRAM
Chassis: INT
Engine: DT466
Rated Cap: Big Girl
CB/Radio Antenna

Picked up a super cheap Uniden PRO505XL CB on amazon, wanting to reuse the antenna already mounted on my bus. Issue is the antenna wire has what looks like a coaxial cable for a TV or VCR, and the CB has much larger connector.

Is the antenna on my bus a good fit for that radio? And will all I need is just adapter?
Attached Thumbnails
IMG_0337.jpeg  
Attached Images
 

bigskypc50 is offline   Reply With Quote
Old 02-21-2020, 06:37 AM   #2
Bus Nut
 
bigskypc50's Avatar
 
Join Date: Dec 2016
Location: MONTANA
Posts: 471
Year: 1995
Coachwork: AMTRAM
Chassis: INT
Engine: DT466
Rated Cap: Big Girl
Since no one answered, I went ahead and ordered the adapter, I will post back if it works!
bigskypc50 is offline   Reply With Quote
Old 02-21-2020, 08:13 AM   #3
Bus Geek
 
Join Date: May 2014
Location: West Ohio
Posts: 3,678
Year: 1984
Coachwork: Bluebird
Chassis: International 1753
Engine: 6.9 International
Rated Cap: 65
That antenna was likely for district communications. We run something similar on all of our buses. The radios they use are all custom motorola jobs that transmit on one frequency to a repeater, and the repeater broadcasts on a different frequency to all the radios.

Coax cable isn't really a complicated thing, so the ends can be changed/swapped or they have adapters too. They likely used the ends they did because they're cheaper or common.

The big thing is that the antenna is likely tuned for a specific frequency the district was communicating on. We're on a vhf band and cb radios work in the hf range, so you might have to modify it to get it to work like it should. It should be able to be used though, but I'm no expert at this stuff, so you need to talk to someone who is. But even if it isn't tuned, you still should be able to broadcast and receive a signal with it.

If it was me, and a cb radio is important to you, I'd take the bus to a radio shop and have them do it. They should have the equipment and know how to tune the whole setup, which can mean the difference between a clear signal for miles and something that's junk.
__________________
My build: The Silver Bullet https://www.skoolie.net/forums/f11/p...llet-9266.html
Booyah45828 is offline   Reply With Quote
Old 02-21-2020, 09:19 AM   #4
Bus Crazy
 
ewo1's Avatar
 
Join Date: May 2015
Location: Central Tx.
Posts: 1,951
Year: 1999
Chassis: Amtran / International
Engine: DT466E HT 250HP - Md3060
Quote:
Originally Posted by bigskypc50 View Post
Picked up a super cheap Uniden PRO505XL CB on amazon, wanting to reuse the antenna already mounted on my bus. Issue is the antenna wire has what looks like a coaxial cable for a TV or VCR, and the CB has much larger connector.

Is the antenna on my bus a good fit for that radio? And will all I need is just adapter?
Different size coax cable will probably have a different "Impedance" measurement so I would be at the very least, know that all coax cable is not the same.

The cable connection itself, CB's require a PL259 connector.
2 standard coax cables are , RG-58 (standard coax) and RG-8x (premium coax).

And if your running dual antennae then you need to use an RG-59 dual antennae coax.

I wouldn't use the antenna already on the bus, it might just work but it will not work optimally. The antenna WILL need to be matched and tuned!

Do it right, go to a cb shop, most major truck stops can point you in the right direction for a CB-guru in the area or just use the web.

Here is one decent site with good basic info.
https://www.wearecb.com/how-to-tune-cb-antenna.html

https://www.wearecb.com/cb-antennas/

good luck!
ewo1 is offline   Reply With Quote
Old 02-21-2020, 09:22 AM   #5
Bus Crazy
 
2kool4skool's Avatar
 
Join Date: Oct 2015
Location: Spring Valley AZ
Posts: 1,343
Year: 2000
Coachwork: Bluebird
Engine: 5.9 Cummins
Rated Cap: 2 elderly children, 1 cat
Dumped the original antenna and went with a 4ft ngp on mirror arm. Got 1.5 to 2 swr. 18ft coax.
Attached Thumbnails
1118191244_HDR.jpg  
2kool4skool is offline   Reply With Quote
Old 02-21-2020, 02:30 PM   #6
Bus Crazy
 
TheHubbardBus's Avatar
 
Join Date: Apr 2019
Location: SW USA
Posts: 2,064
Year: 2003
Coachwork: IC / Amtran
Chassis: CE300
Engine: International T444e
Rated Cap: 23
Like Booyah already hit on, you can't just hook up any old antenna. That goes for everything, not just CBs. All antennas are designed to work only within a given frequency range. Not only is that antenna almost certainly not a match for 11m (which is the wavelength of CB comms), it's probably WAY off. Getting it to work for CB applications shouldn't even be considered. If you do attempt to use it, on receive you'll get extremely poor performance, and on transmit you could literally damage your transceiver (unless the excessive SWR causes protective circuitry it may or may not have to shut it down before damage does occur which would be best case).

Don't use anything other than a CB-specific antenna (50 ohms impedence).

Also, like EWO said, coax impedence is a consideration. Anything made for mobile radio is going to be 50 ohms, & that's what you want. 75 ohms is cable TV, & that's what you don't. 11m generates very little coax loss, so you don't have to get fancy. RG58 is what I'd recommend, unless you're looking to upgrade sometime in the future to a ham license, in which case rg-8x would is still real easy to run & would do better at VHF/UHF frequencies.
__________________
Go away. 'Baitin.

Our Build: Mr. Beefy
TheHubbardBus is offline   Reply With Quote
Old 02-21-2020, 03:17 PM   #7
Bus Geek
 
Join Date: May 2014
Location: West Ohio
Posts: 3,678
Year: 1984
Coachwork: Bluebird
Chassis: International 1753
Engine: 6.9 International
Rated Cap: 65
Yeah, I didn't even think about tv coax and it's impedence. I haven't messed with anything but 50 ohm in what seems like forever.

But the moral of the story is that your antenna in it's current fashion isn't going to work worth a ****.

Best bet is to visit a radio shop.
__________________
My build: The Silver Bullet https://www.skoolie.net/forums/f11/p...llet-9266.html
Booyah45828 is offline   Reply With Quote
Old 02-21-2020, 05:23 PM   #8
Bus Geek
 
Join Date: Sep 2015
Posts: 3,856
Year: 2002
Coachwork: Thomas Built Bus
Chassis: Freightliner FS65
Engine: Caterpillar 3126E Diesel
Rated Cap: 71 Passenger- 30,000 lbs.
Follow 2kool4skool's lead on this one ... replace the antenna with one made for the CB frequencies.
Native is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 08:54 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2024, vBulletin Solutions, Inc.