| Author |
Message |
    
Charliebrown
Intermediate Member
Username: Charliebrown
Post Number: 232
Registered: 10-2002
| | Posted on Sunday, October 23, 2011 - 6:45 pm: | 
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Upon reading the claim of this antenna, (which is a single coax hook up) I thought that a vertical antenna could not have a multiplication factor as that like a beam antenna. Nor could I see a 7.75 db gain from this vertical antenna. Other than antenna hype from the company to sell this antenna for $419.00, could someone explain to me how this could be possible be if true? |
Tech237
Moderator
Username: Tech237
Post Number: 1482
Registered: 4-2004
| | Posted on Monday, October 24, 2011 - 8:50 am: |
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CB vertical antennas can have gain, in fact for repeater systems I have buiolt vertical antennas with 10dbd or better gain by using phased elements. Now to do so on 27MHz would creat a rather large antenna, and a 3/4 wave would not be large enough.
Of course it is interesting to note that they spec do not state 7.75db compare to what. So yes, it may have 7.75db gain compared to a 6" piece of wet string, but compared to a standard halfwave dipole - errrrr I cannot see it.
Maybe 833 will have some better information.
Tech237
N7AUS
God only made some many perfect head, on the rest he put hair.
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Charliebrown
Intermediate Member
Username: Charliebrown
Post Number: 233
Registered: 10-2002
| | Posted on Monday, October 24, 2011 - 1:00 pm: |
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Tech 237, Thank's for the information. What also had blown my understanding of vertical antenna's is their claim of a multiplication factor of 19x. I can not see a vertical give any multiplication like a beam antenna unless it is a beam. So if I am incorrect, someone enlighten me so I would know better. Also if I am correct, how could they get by with false or misleading information? |
Press_man
Intermediate Member
Username: Press_man
Post Number: 252
Registered: 5-2008
| | Posted on Monday, October 24, 2011 - 2:56 pm: |
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If memory serves, seems like every vertical GP I've had have always claimed a X4, but X19? Cough/gag.
Pressman/KC4ZWM
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Tech237
Moderator
Username: Tech237
Post Number: 1483
Registered: 4-2004
| | Posted on Thursday, October 27, 2011 - 9:12 am: |
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You can have verticals antennas that are not beams with gain, but you normally wont find them down around 27MHz because of the size factor. I don't have the figures here at work, but get 7.75Db gain over a dipole, a phased array vertical would need 5 or 6 elemetns EACH a half-wave long. So 6 x 18 = 108ft at 27MHz. A 3/4 wave or 5.8 wave may have some gain over a half-wave, but certainly not the 7/75Db quoted.
Hey 833 step in here and add you better information, anytime now.
Tech237
N7AUS
God only made some many perfect head, on the rest he put hair.
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Charliebrown
Intermediate Member
Username: Charliebrown
Post Number: 234
Registered: 10-2002
| | Posted on Thursday, October 27, 2011 - 10:17 am: |
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I agree but, I do not see how some can get by with the false claim's when selling any product. If they are not speaking truth to the customer's then why would anyone still do business with them? |
Tech237
Moderator
Username: Tech237
Post Number: 1485
Registered: 4-2004
| | Posted on Friday, October 28, 2011 - 9:53 am: |
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CB thats the eaiser question to answer - because people as a whole (and some more so than others) are gullible, and believe what is printed or posted on the net.
The whwole advertising industry makes use of that simple fact.
Tech237
N7AUS
God only made some many perfect head, on the rest he put hair.
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