| Author |
Message |
    
Kattracker
| | Posted on Monday, September 01, 2003 - 3:45 pm: | 
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It seems I have read somehwere recently that the whips in the earlier (1960's) days, the stainless steel whips were 108 inches long. Also the article stated that the modern day whips were reduced to 102 inches to allow for a spring which then takes it back to 108 inches.
Considering that, then would the stainless whip be a slight bit more efficient when used with a spring, considering it would be 108 inches, which is a true 1/4 wave?
Any comments?
Thanks,
Kattracker |
Wildbill
| | Posted on Monday, September 01, 2003 - 4:01 pm: |
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True Qtr. Wave = 108" |
ryan
| | Posted on Monday, September 01, 2003 - 4:13 pm: |
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true 1/4 wave is had from the balance between the radiator (whip) and a counterpoise (car body) its all the same |
bruce
| | Posted on Monday, September 01, 2003 - 4:19 pm: |
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also copper and steel have slightly diffrent lenght due to current flow at rf |
Kattracker
| | Posted on Monday, September 01, 2003 - 7:07 pm: |
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Wildbill,
I did not ask my question right, my fault.
What I meant to ask was which antenna will be more efficient, The 102 or the 108? I am aware the 108 is the true 1/4 wave.
When I said " which is a true 1/4 wave" was a statement at the end of my question.
Again, my fault. After re-reading my post I see how it could have been misunderstood.
Thanks,
Kattracker |
Kattracker
| | Posted on Monday, September 01, 2003 - 7:09 pm: |
|
Wildbill,
I did not ask my question right, my fault.
What I meant to ask was which antenna will be more efficient, The 102 or the 108? I am aware the 108 is the true 1/4 wave.
When I said " which is a true 1/4 wave" was a statement at the end of my question.
Again, my fault. After re-reading my post I see how it could have been misunderstood.
Thanks,
Kattracker |
Buck
| | Posted on Monday, September 01, 2003 - 7:39 pm: |
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I have a 102" whip on my truck and I get better SWR without the spring. My swr without the spring is 1.2:1 and with it is 1.5:1. Not much of a differance but enough for me to run without it. One other reason I dont run the spring is that I tend to get alot more flop in the antenna that I dont like
Buck |
Kd4amg
| | Posted on Monday, September 01, 2003 - 9:17 pm: |
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i agree about the " flop " in the antenna... it is distracting ! |
Funtimebob
| | Posted on Tuesday, September 02, 2003 - 3:38 am: |
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lets see.. the shorter the antenna the higher the freq. 108" older model from 23 ch. days. 102" newer 40ch era.......... |
bruce
| | Posted on Tuesday, September 02, 2003 - 10:49 am: |
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funtime
not true the 102/99/108 lengh is because of the 6 in spring or copper / steel material for the wip not 23/40.
A 6 inch diffrence at 27 on a 1/4 wave would rase the frequency by 1.5 mhz putting it into the 10 meter band |
Sarge
| | Posted on Wednesday, September 03, 2003 - 4:39 pm: |
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I don't think there would be a noticable difference on the air between a SWR of 1.2:1 and 1.5:1.
If adding a 6-inch spring really affects the resonant frequency of the whip antenna, it would make the antenna longer - thus lowering the resonant frequency. That would put it down in below 26 MHz instead of up into 28 MHz.
Problems with the antenna having too much flex at highway speeds would certainly justify skipping the spring. I have known of folks using fishing line to stabilize the whip antenna in a vertical position. If they ever actually hit an overhead obstruction such as a tree limb, the fishing line would snap and allow the whip to flex backwards. A simple idea that seems to work well. |
jo-gunn-fann
| | Posted on Friday, September 05, 2003 - 7:11 am: |
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Bruce will the 108" out talk a jo-gunn fighting stick. |
Bruce
| | Posted on Friday, September 05, 2003 - 8:15 am: |
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I looked but could not find a " fighting stick"
As for a 102/108 wip with a good ground plane they are as good as any antenna out there. Now as for jo gunn i still want to see the field tests on ANY of the antennas and how you measure audio gain |
Bigbob
| | Posted on Friday, September 05, 2003 - 7:18 pm: |
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12 LB.test stren line half way up with a light duty high rate spring at the hood,that will stretch to 3 feet then snap back,but still hold nearly vertical at 70 mph.Top half still flexes enough to clear over-passes,perfect. |
Tech671
| | Posted on Saturday, September 06, 2003 - 5:45 am: |
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A "fighting stick" * IS * a 108 whip, just larger material. |
Bruce
| | Posted on Saturday, September 06, 2003 - 8:35 am: |
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ok then it would tend to have wider bandwidth
to answer his question mounted on the same mount at center frequency no diffrence at 4 watts |
Moderator558
| | Posted on Saturday, September 06, 2003 - 9:36 am: |
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how about the ICOM 102 inch whip for 289 dollars
that thing is very large diameter and with a AH4 you can tune 7 to 54 mHz
take a look here
http://www.amghummer.com/radio/icom_install/icominstall.htm |
Bruce
| | Posted on Saturday, September 06, 2003 - 2:19 pm: |
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cool idea that icom i use HAMWIPS they are 7 foot each i have 20, 17, 15 and 10 meters each covers the band just fine as for tunners i sent my brother one of the dx-70's i had so he can run moble again and the other im thinking of running in the car with a smart tuner......must be nice to own a HUMMER...... |
