102 whip on jeep liberty. SWR issues.

[Marconi]

Well 350, common sense tells me that if your bumper is plastic, this idea does not apply to your setup.

 

[mustang_gt_350]

I know many CBr's can see RF and electrical currents flowing in the air and on their antennas. That is why we hear so many good references to what is going on in the real world of CB radio.

So, when they tell us that a mobile whip won't work attached to a P/U truck bumper...they are probably talking out......

Unlike many CBr's I don't know exactly how currents flow or how they are effected by their surroundings, because I can't see this stuff. But, here is what Eznec indicates is likely going on with a model of a pick up truck with a 1/4 wave whip mounted on the center top of the cab vs. the same with it mounted on the outer edge of rear bumper.

I have <gotproof> and I have words too.

View attachment 10782

In these examples it is permissible for you to look at the pictures after you read my words for what the models represent. If you have questions, please read the manual...available on line.

This mobile model was provided to me by our member Henry in Holland, I think.

Wow, so its saying it works better on the bumper?? Not exactly sure i understand the pics..

 

[Lil'Yeshua]

I thought about mounting a 102" on my spare tire carrier on my Tracker which is just like the jeep but I'm enjoying my Sirio right now. Don't know where I want the hard mount to go yet.

 

[Lil'Yeshua]

Wow, so its saying it works better on the bumper?? Not exactly sure i understand the pics..

I was looking at the total field pic that Marconi posted. That's what I look for for distance performance.

 

[mustang_gt_350]

I was looking at the total field pic that Marconi posted. That's what I look for for distance performance.

the bumper mount right? Just trying to learn as it looks like it covers more area?

 

[Lil'Yeshua]

the bumper mount right? Just trying to learn as it looks like it covers more area?

Marconi and the others are more experienced than I am. My own personal experience is that you can have a beam effect off the opposite end/corner of the car. Not much for 360% coverage but great if you like using it as a beam.

 

[mustang_gt_350]

Ok, just got a brainstorm. I noticed the total lenght on that pdf was like 109". I got to thinking so i pulled my antenna and measured it, its 107" my spring is just a tad over 4" aren't they supposed to be 6"

So i rigged a extention onto the top of the antenna from a steel clothes hanger. I made about 3" of it stick out of the top of the antenna and electrical taped it to the top of the whip. Reinstalled and reread the swr. I'm now at 1.6 on 1 and 1.5 on 40.

So is the a good way to test if the antenna was too short with that spring? Or is the extra mass next to the tip of the whip messing up the actual SWR and fooling it into making it think its the proper legnth?

 

[Robb]

Ok, just got a brainstorm. I noticed the total lenght on that pdf was like 109". I got to thinking so i pulled my antenna and measured it, its 107" my spring is just a tad over 4" aren't they supposed to be 6"

So i rigged a extention onto the top of the antenna from a steel clothes hanger. I made about 3" of it stick out of the top of the antenna and electrical taped it to the top of the whip. Reinstalled and reread the swr. I'm now at 1.6 on 1 and 1.5 on 40.

So is the a good way to test if the antenna was too short with that spring? Or is the extra mass next to the tip of the whip messing up the actual SWR and fooling it into making it think its the proper legnth?

Yup.
Think it would be a fine idea if you just replaced that old, rusty spring with a new 6" spring and be done with it and enjoy what you have?

 

[Lil'Yeshua]

Fancy and with ground wire
Hustler Stainless Steel Springs with Coupling Stud - Free Shipping on Orders Over $99 at DX Engineering



4.165" tall

 

[mustang_gt_350]

Yup.
Think it would be a fine idea if you just replaced that old, rusty spring with a new 6" spring and be done with it and enjoy what you have?

I'm just trying to get the SWR the best i can as i eventually plan on putting a small booster on it and i don't want to fry it from a poor swr.

I'll pick up a 6" spring and see if that helps, it can't hurt. I pulled the spring over and the center wire looks pretty corrodid, that may not be helping me much either.

Thanks for all the help

I also finally got my base super magnum down to 1.5 across the board not bad for free.

 

[6string]

I have the hustler 6" inch spring for mine mine seems to work well but mine isnt on a liberty

 

[Marconi]

Fancy and with ground wire
Hustler Stainless Steel Springs with Coupling Stud - Free Shipping on Orders Over $99 at DX Engineering

4.165" tall

Lil'Y...where do you get the idea of a ground wire on the spring link you posted? Stainless steel spring and center wire should be a lot better too.

 

[mustang_gt_350]

Fancy and with ground wire
Hustler Stainless Steel Springs with Coupling Stud - Free Shipping on Orders Over $99 at DX Engineering



4.165" tall

This is the same legnth spring i have now and its too short.

 

[Beetle]

I didn't see anything about you removing the jumper cables, but do yourself a favor and remove them if you haven't. They're what ... 8 feet long - maybe 12 feet long? The grounding has to be as short and direct as possible.

 

[mustang_gt_350]

I didn't see anything about you removing the jumper cables, but do yourself a favor and remove them if you haven't. They're what ... 8 feet long - maybe 12 feet long? The grounding has to be as short and direct as possible.

I cut them, They are about 3-4 feet. Just long enough that i can open the gate all the way and not have them tight.

I am going to try it without them in a few mins just to see if they are even needed or it it was antenna lenght the whole time. I may be able to add a disconnect but i can't find how long they usually are?