[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: Fw: ELK or ARROW



Art

Well said . . . . I love fooling around with antennas of all sorts . . . 
hard for some to build rigs but antennas much easier projects . . .  a ton 
of engineering info out there as you say . . .  ARROW  and ELK work but can 
work better with some tweaking . . .  have fun . . . there is DBi 
(isotropic) and DBd (dipole) but do not forget  DBa  (advertising) the 
latter is more abused than the other two . .

Jim W9VNE

----- Original Message ----- 
From: "Art McBride" <kc6uqh@cox.net>
To: "'Jim Danehy'" <jdanehy@cinci.rr.com>; <amsat-bb@amsat.org>
Sent: Saturday, December 27, 2008 9:59 PM
Subject: RE: [amsat-bb] Fw: ELK or ARROW


> To All,
> 1. Amateur Radio is learning by doing.
> 2. A large amount of data on Yagi type antennas exists, easily found, and 
> is
> well proven.
> 3. Several design programs for antennas exist reducing construction time 
> and
> waist of materials.
> 4. Equipment to measure comparative antenna performance at VHF/UHF
> frequencies is not hard to find.
>
> Why do we line the pockets of some poorly designed antenna manufacturing
> companies instead of learning how and making the best performing antennas
> for our own use? If we do not learn these skills, no one will be left to
> teach and the skills will be lost.
>
> There are many older Amateurs willing to teach those that want to learn, 
> and
> hopefully many of those wanting to learn are at least one half of the age 
> of
> those who can teach!
>
> Art,
> KC6UQH
>
> -----Original Message-----
> From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On
> Behalf Of Jim Danehy
> Sent: Saturday, December 27, 2008 6:33 PM
> To: amsat-bb@amsat.org
> Subject: [amsat-bb] Fw: ELK or ARROW
>
>
> .  there is the old adage that you get what you pay for . . . why buy a
> poorly designed antenna that does not work very well
>> ?
>>
>> If you have a 5 element  yagi that only produces 4 dbi you are not 
>> getting
>
>> what you paid for . . . most 2 element yagis would out perform that
>> statistic . . . a 5 element yagi should be at least 9 db + or 10 db dbd
>> (dipole ) not isotropic  . . . . there is something that is called
>> MERCHANTABILITY . . .i.e., an IMPLIED WARRANTY  that you are getting at
>> least the minimum for your money . . .
>> 4 dbi for an Arrow is way off base . . .  so it is not just ; you can not
>> afford a Cadillac but you are not even getting a Ford or Chevy  . . 
>> i.e.,
>
>> the gain of a 5 element yagi on 435 mhz . . .  that is the issue, not 
>> cost
>
>> alone . . . . . . same comments apply to the ELK but I have attempted to
>> make the point that there is a minimum performance for a certain number 
>> of
>
>> elements that is pretty OBJECTIVE and when it is not met  . . . . well
>> that is my point . . . these two antennas have shown to some testers that
>> they do not measure up to the minimum EXPECTATIONS . . .unfortunately 
>> that
>
>> is acceptable to some  . . . . then it becomes acceptable to many . . .
>> and objectivity is abandoned . . .
>>
>> Jim W9VNE
>>
>>
>> ----- Original Message ----- 
>> From: "Trey Brown" <palintheus@gmail.com>
>> To: "Jim Danehy" <jdanehy@cinci.rr.com>
>> Sent: Saturday, December 27, 2008 6:39 PM
>> Subject: Re: [amsat-bb] ELK or ARROW
>>
>>
>>> Thanks for the comments. Realize, though, that not everyone wants or
>>> can afford to have the Cadillac.
>>>
>>>
>>> On Sat, Dec 27, 2008 at 4:06 PM, Jim Danehy <jdanehy@cinci.rr.com> 
>>> wrote:
>>>> the Arrow antenna has been critiqued by Kent Britain, WA5VJB
>>>>
>>>> http://wa5vjb.com/references/Cheap%20Antennas-LEOs.pdf
>>>>
>>>> he says that some have measured the Arrow for gain on 435 mhz @ 4 dbi
>>>> (isotropic) . . . . and that further analysis showed that for the
>>>> element lengths used on 435 mhz that it peaks at 457 mhz and not 435 
>>>> mhz
>
>>>> . . . Kent is a well respected VHF/UHF antenna person who has plenty of
>>>> credibility . . .
>>>>
>>>> Kent opines that the Arrow, as built does not have its elements
>>>> insulated from the boom. It uses dimensions for insulated elements . . 
>>>> .
>
>>>> so much for the Arrow . . . .
>>>>
>>>> Now for the ELK  : a local friend of mine owns an Arrow and he uses it
>>>> successfully. He bought an ELK and attempted to compare the Arrow and
>>>> the ELK . . . . he could not make an across town QSO on 435 mhz from 
>>>> his
>
>>>> second story window with the ELK , so he sent the ELK back for a refund
>>>> .
>>>>
>>>> I have worked and exchanged QSLs with several hundred satellite users .
>>>> . .the majority of the folks that have worked and QSLed me (close to 
>>>> 250
>
>>>> + ) have been using either the Arrow or ELK based upon the information
>>>> on their cards. So they are popular. Are they optimum ? A lot of
>>>> anecdotal information would seem to say NO . . .
>>>>
>>>> Thirty-five years ago I worked Oscar 6 with a homebrew 2 mtr yagi that
>>>> probably was worse than either the Arrow or Elk but I worked YV and KL7
>>>> from Indiana on CW with about 15 watts to the 3 elements which my XYL
>>>> waved around at my directions . . . not any more . . .what do I use
>>>> these days : a pair of circular polarity yagis on 10 foot booms
>>>> manufactured by M Square . . . .
>>>>
>>>> Folks ask what should they buy ? Maybe a Ford or maybe a Chevy . . .
>>>> neither is a Cadillac . . . .
>>>>
>>>> Jim W9VNE
>>>> _______________________________________________
>>>> Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the 
>>>> author.
>>>> Not an AMSAT-NA member? Join now to support the amateur satellite
>>>> program!
>>>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>>>>
>>>
>>>
>>>
>>> -- 
>>> Trey -- N5THX
>>>
>>> They who can give up essential liberty to obtain a little temporary
>>> safety, deserve neither liberty nor safety.
>>> - Benjamin Franklin
>>>
>>
>
> _______________________________________________
> Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>
> __________ Information from ESET NOD32 Antivirus, version of virus 
> signature
> database 3719 (20081227) __________
>
> The message was checked by ESET NOD32 Antivirus.
>
> http://www.eset.com
>
>
>
>
> __________ Information from ESET NOD32 Antivirus, version of virus 
> signature
> database 3719 (20081227) __________
>
> The message was checked by ESET NOD32 Antivirus.
>
> http://www.eset.com
>
>
> 

_______________________________________________
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb



AMSAT Top AMSAT Home