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Which mobile antenna would you choose for distance?

Which one would you choose for straight talk distance?


  • Total voters
    17

Recon

NY 881
Jul 28, 2019
724
934
103
Up-State NY
You mean to tell me they make another antenna besides a Predator?
Ha! ha! You are funny.
You should not place the Predator in the bed of the truck when not in use unless you have a piece of PVC pipe with a 3-1/4" or 3-1/2" inside diameter to store the antenna to protect the coil from distorting and prevent the weld joint on each end of the coil from cracking.
 

Recon

NY 881
Jul 28, 2019
724
934
103
Up-State NY
108" SS steel whip.
Correct me if I am wrong.
The stand-alone length of a stainless steel whip is 102".
Attaching the whip to a 6-inch spring = 108".
Attaching the whip and spring to a ball-mount, stake-pocket mount, etc. etc. will increase the total length / height to above 108". Can we assume the excess of 108" will have a negative affect on the SWR?
I read somewhere that the length of the antenna starts where the coax connector attaches to the antenna connector.
I conducted a "science fair / experiment" with my whip antenna installation using a 102" stainless steel whip, a 4-1/4" heavy duty stainless steel spring and a Breedlove Stake Pocket Mount with quick-disconnect fitting.
Total length of the stake-pocket mount w/quick-disconnect = 4.970" + 4.250" (spring) + 102" whip = 111.220". I removed the whip from the base by removing the two set-screws and trimmed-off the bottom of the whip to obtain a total length of 108" and the SWR is great!
 

Recon

NY 881
Jul 28, 2019
724
934
103
Up-State NY
Lol...lol..lol. Yeah, those tall whips are ugly, but they do the job well.

Remember the song by Jimmy Soul? "If You Want To Be Happy"
Say man!
Hey baby!
I saw your wife the other day!
Yeah?
Yeah, an' she's ug-leeee!
Yeah, she's ugly, but she sure can cook, baby!
Yeah, alright!
 

The DB

Sr. Member
Aug 14, 2011
1,984
1,458
193
St. Louis, MO
Attaching the whip and spring to a ball-mount, stake-pocket mount, etc. etc. will increase the total length / height to above 108". Can we assume the excess of 108" will have a negative affect on the SWR?

The answer is "yes but". If an antenna is to long electrically, you will see SWR go back up. However, most 102" whip installs are so wide banded that it takes quite a bit of length to get SWR to go up to the point of being dangerous.

I read somewhere that the length of the antenna starts where the coax connector attaches to the antenna connector.

This is half true. If you just looking at the whip length you are only looking at half of the mobile antenna system. The chassis of the vehicle plays a big part in this as well. Smaller vehicles need a slightly longer whip to tune to the lowest SWR point, while larger vehicles need a slightly shorter whip length. Further, where the antenna is on the vehicle makes a difference as well as simply moving an antenna may require retuning it to maintain the lowest SWR point.

That being said, a 1/4 wavelength whip is naturally very wide banded, so it wouldn't surprise me if both the 102" and 108" lengths both give an acceptable SWR, and I have seen this happen before. In this case, based on field strength measurements, you will tend to get better performance if the antenna is a little long as opposed to being a little short, so I would error on being slightly long.


The DB
 

86lidewell

Well-Known Member
Oct 10, 2020
140
172
53
53
DFW Texas
Correct me if I am wrong.
The stand-alone length of a stainless steel whip is 102".
Attaching the whip to a 6-inch spring = 108".
Attaching the whip and spring to a ball-mount, stake-pocket mount, etc. etc. will increase the total length / height to above 108". Can we assume the excess of 108" will have a negative affect on the SWR?
I read somewhere that the length of the antenna starts where the coax connector attaches to the antenna connector.
I conducted a "science fair / experiment" with my whip antenna installation using a 102" stainless steel whip, a 4-1/4" heavy duty stainless steel spring and a Breedlove Stake Pocket Mount with quick-disconnect fitting.
Total length of the stake-pocket mount w/quick-disconnect = 4.970" + 4.250" (spring) + 102" whip = 111.220". I removed the whip from the base by removing the two set-screws and trimmed-off the bottom of the whip to obtain a total length of 108" and the SWR is great!
better too long than too short!
 

AudioShockwav

Extraterrestrial
Staff member
Apr 6, 2005
7,239
4,770
343
Sierras Near Yosemite National Park
Ha! ha! You are funny.
You should not place the Predator in the bed of the truck when not in use unless you have a piece of PVC pipe with a 3-1/4" or 3-1/2" inside diameter to store the antenna to protect the coil from distorting and prevent the weld joint on each end of the coil from cracking.

Cale doesn't weld the 10K coils to the shaft.
The only real problem I have ever had with his antennas is the set screw that holds the whip in can become stuck and required heat to get it out without destroying the threads.
I did some on the air testing years ago with a 22 inch shaft, a 27 inch shaft , both single coils, and a 96 inch fiberglass whip.
There was not that much difference.
And this was done mobile to base, @100 miles plus and on 10, 11, and 12 meters.


73
Jeff
 

The DB

Sr. Member
Aug 14, 2011
1,984
1,458
193
St. Louis, MO
@The DB what if I don't want any errors???

I would expect that someone of your experience could McGyver something, especially on the 11 meters band... Wait, those words together sound familiar for some reason... :LOL:

For those that can't do such things, luckily their isn't to much of a cost in being "close enough", (yep, that is definitely a technical term) at least not so much that they will notice the difference when actually using the equipment.

What was it that always shows up in Marconi's signature?

We're just lucky that Mother Nature doesn't require our antenna systems to be perfect in order to work our radio.

If someone who doesn't have the knowledge wants to do this, then they have two options.
  1. Get someone who has the knowledge and equipment to do it for them
  2. Buy the equipment and study to the point that they can do it themselves.
Nothing against the people who settle for close enough, or go with option 1, the depths of knowledge in this field is not for everybody. Much respect for those who strive for option 2, even if in the end they don't succeed.


The DB
 

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