duradoane
Member
 Offline
Posts: 21
It happens
|
 |
« Reply #15 on: November 06, 2009, 09:31:53 PM » |
|
I was thinking pickup.
Is the base of the antenna on top of the headache rack or lower? If that antenna doesn't have any 'breathing room' any metal around it will reflect your signal right back into the antenna, down the coax into the radio final. Not good.
How much 'breathing room' does it need? I had to mount it lower and the height right now is about 13' 6". Don't really have a lot of other options. |
|
|
|
|
Logged
|
|
|
|
|
SA104-PM
|
|
« Reply #16 on: November 06, 2009, 09:39:12 PM » |
|
Re: Breathing Room
I have a 102 whip on my F-150 pick-up. the breathing room I gave it was on the bed rail, one foot behind the cab
|
|
|
|
|
Logged
|
|
|
|
Train
CBTricks Supporter
Hero Member
Offline
Posts: 1097
Avatar by Gary Blizzard ©
|
|
« Reply #17 on: November 06, 2009, 09:53:48 PM » |
|
Any metal parallel and in close proximity to a radiating antenna is not good. The more you have the more reflected signal that will have to be dealt with.
Too much trouble. For a test have someone with a broom handle sway the antenna while you are taking a SWR reading and watch the needle swing in harmony with the whip.
|
|
|
|
|
Logged
|
|
|
|
|
sportmix
|
|
« Reply #18 on: November 06, 2009, 09:54:27 PM » |
|
Your antenna mounted on a headache rack will not function very well because of lack of an adequate RF ground i.e. groundplane.
RF Ground runs on the surface area, the more surface area you have , the better the ground.....hence dead center of the cab of a pick up , car, or pickup. now that is my 3 cents.......lol
|
|
|
|
|
Logged
|
|
|
|
duradoane
Member
Offline
Posts: 21
It happens
|
|
« Reply #19 on: November 06, 2009, 10:16:34 PM » |
|
Would I be better off putting the 102" whip on my pickup mounted in the center on an aluminum toolbox about 3' back from the back window? Would I need a groung wire to the antenna mount since it is aluminum? And then put the dual 4' Firesticks from the pickup on the mirrors of my semi? I'm getting frustrated with this one guys!!!!
I would rather keep the 102" whip on the semi but I don't really have any other options.
|
|
|
|
|
Logged
|
|
|
|
|
sportmix
|
|
« Reply #20 on: November 06, 2009, 10:33:39 PM » |
|
Just my opinion, you would be better using the fiberglass antenna, or buy a wilson 2000 and mount on one mirror. running wire like a number 12 is useless........remember rf ground runs on the surface , that is why you see ground straps on your truck, car, or pickup grounding the body to the rails.
Grounding issue on semi trucks can be very difficult, the newer they are, the harder it is. BTW, nothing wrong with mounting antenna on aluminum. Things on trucks that will not give you any ground is fiberglass, plasitic, etc. As you know a lot of the newer trucks (mack, freightliner, etc) has a lot of fiberglass on the cab, including the door. I've even seen some parts of the mirrors are plastic, sooooo be sure what you mount to.
|
|
|
|
|
Logged
|
|
|
|
duradoane
Member
Offline
Posts: 21
It happens
|
|
« Reply #21 on: November 06, 2009, 10:38:37 PM » |
|
So would the 102" be ok on the pickup about 3' back off the back window and in the center?
|
|
|
|
|
Logged
|
|
|
|
|
§m¦±±¥
|
|
« Reply #22 on: November 06, 2009, 11:53:33 PM » |
|
I had my 102" mounted as the picture shows below on my little truck, and the SWR was flat as hell, but being directly on the rail, it was high:  |
|
|
|
|
Logged
|
The Quack ShackThere are three kinds of people: those who can count...and those who can't
|
|
|
|
sportmix
|
|
« Reply #23 on: November 07, 2009, 12:16:02 AM » |
|
what are you going to mount it on 3 feet back on your pickup? Tool Box? if so, it should work fine, as long as the toolbox is mounted to the bed with screws/bolts and its not sitting on top of a plastic rail cover.
|
|
|
|
|
Logged
|
|
|
|
Train
CBTricks Supporter
Hero Member
Offline
Posts: 1097
Avatar by Gary Blizzard ©
|
|
« Reply #24 on: November 07, 2009, 06:33:52 AM » |
|
Its mounted on the headache rack which is custom built out of steel with a 90k winch in it. He's talking 'big truck' here and if the antenna's height is set 13' 6" then the mounting area is pretty close to frame height. That's a lot of metal from the headache rack around that antenna to reflect back... |
|
|
|
|
Logged
|
|
|
|
|
§m¦±±¥
|
|
« Reply #25 on: November 07, 2009, 09:12:32 AM » |
|
Hell, I thought this was going to go on a pickup truck. I gave up on the 102" on a big truck dream. TW is right, that's a lot of metal for reflect, and I have never been able to get a 102" to work correctly on a big truck.
The only way I did get it to half way work, was mounted top dead center of the headache rack, but that put the top of the antenna somewhere around 17 to 18' tall. Bridges loves me! It had to come off eventually, due to my worrying about it all the time.
|
|
|
|
|
Logged
|
The Quack ShackThere are three kinds of people: those who can count...and those who can't
|
|
|
|
sportmix
|
|
« Reply #26 on: November 07, 2009, 09:56:02 AM » |
|
From what I gather, he is talking about a semi and pickup.
|
|
|
|
|
Logged
|
|
|
|
Train
CBTricks Supporter
Hero Member
Offline
Posts: 1097
Avatar by Gary Blizzard ©
|
|
« Reply #27 on: November 07, 2009, 10:21:11 AM » |
|
Turning into a guessing game... lol A picture would sure clear things up.. A 90,000# winch in a headache rack would sure be an over kill on a pickup...  Hell, I'd like to see a pic just to get a look @ a 90K winch.  Familiar with the Tulsa 64 and they're stout! |
|
|
|
« Last Edit: November 07, 2009, 10:48:17 AM by Train »
|
Logged
|
|
|
|
|
SA104-PM
|
|
« Reply #28 on: November 07, 2009, 07:36:58 PM » |
|
is this truck one of those tilting flat bed Wreckers??
|
|
|
|
|
Logged
|
|
|
|
Train
CBTricks Supporter
Hero Member
Offline
Posts: 1097
Avatar by Gary Blizzard ©
|
|
« Reply #29 on: November 07, 2009, 07:49:01 PM » |
|
A roll-back? I would think what he's referring to is at least a three axle, class 8 truck. "Large car".  |
|
|
|
« Last Edit: November 07, 2009, 07:55:37 PM by Train »
|
Logged
|
|
|
|
|
