[Antennas] Best 'no radials' HF vertical?

2002年8月16日 12:30:16 -0400 (EDT)

 Hi Jim:
 Since you have identified your space limitation and the desire have multiband capability, considering a "radialess" vertical makes sense. You are clearly aware of its limitations, so it is just a matter of picking the best offered.
 I have (and still do) own the MFJ 1796 and the Cushcraft R-7 (preceeded the R-7000) which both utilize the end fed window theory of operation. The one thing I take away from using both of these antennas is that more metal is better. The MFJ-1796 at 12 feet tall was not as good as the R-7 at 20 or so feet. So, if you are not limited vertically, I would line up the contenders and select the tallest one offered. 
 While I am not familiar with the trapless model you mentioned, this should be a plus if it was not significantly shorter than the others. 
 One last observation. Cushcraft has had a history of providing little or expensive support for those needing part replacement on their antennas. Either they want you to purchase half the antenna to get at a single part or want way to much money for the part desired. The R-7000 and R-7 both had a tendency to burn out traps (although this was probably due to owners trying to run power with SWR readings that exceeded 1:1.5) and this lead many users to realize that Cushcraft was not as supportive to their customers as they could be.
 Good luck.
Ron W7MRR
 --- On Fri 08/16, Jim Shaw wrote:
From: Jim Shaw [mailto: [email protected]]
To: [email protected]
Date: 2002年8月15日 21:05:43 -0700
Subject: [Antennas] Best 'no radials' HF vertical?
> Because verticals with 'no radials' are sometimes an emotional topic, I
> have
> been hesitant to ask for feedback on them. However, due to a sudden
> decrease in my already limited space for antennas, I am now seriously
> contemplating the acquisition of a 'no radials' vertical antenna in order
> to
> remain on the air until I can move to a new QTH with more space. 
> Hopefully,
> I can obtain a vertical that covers all bands, including WARC, from 40
> thru
> 10 M and will take the full legal power limit.
>> From what I can tell, there are three commercial possibilities: 1) the
> Cushcraft R8, 2) the Hy-Gain AV-640, and 3) the Hy-Gain DX-77A. In order
> to
> familiarize myself with what kind of performance I might expect, I
> obtained
> the publication "HF Vertical Performance Test Methods and
> Results" by N0AX
> and K7LXC published in 2000 and obtainable via
> http://www.championradio.com/forsale/ . This report compared the
> Cushcraft
> R8 'no radials' vertical to the Butternut HF6V, MFJ 1798, Force-12 ZR-3,
> Diamond CP-6, Hustler 6BTV, Force-12 V-3, and Gap Titan. In addition,
> from
> my own personal experience, I've used the Cushcraft R-4 (the very first
> commercial 'no radials' HF vertical?) as a 'backup' antenna for nearly 15
> years.
>> I had pretty much settled in on the R8 because, among other things, it
> uses
> fewer traps than the Hy-Gain DX-77A. Also, its 'counterpoise' elements
> are
> only 4 feet long thus I could install it in a space no wider that 9 feet
> by
> 9 feet. However, recently, I noticed that Hy-Gain now offers a new, 'no
> radials' vertical' - the AV-640. This new AV-640 not only has 'no
> radials',
> it also has 'no traps'! I downloaded the manual and found that it
> contains
> a nice 'theory of operations' discussion and the design makes a lot of
> sense
> to me. But, I'm no expert on this topic.
>> So, assuming you were limited to putting up a single 'no radials'
> vertical
> and wanted to operate high power on 40 thru 10 M, which one of these
> three
> verticals would you choose and why? Or, is there a better alternative
> possible within my limited space that I have not considered?
>> 73 de Jim [email protected]
>> - - - 
>> Your moderator for this list is:
> Larry Wilson KE1HZ [email protected]
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