[TowerTalk] Opinions on the Cushcraft R-7000+ Vertical --

Bill Coleman AA4LR aa4lr@radio.org
Sun, 29 Nov 1998 18:14:08 -0500

On 11/13/98 10:28, LUST AUCTION SERVICES - Verona, WI at 
rlust@madison.tds.net wrote:

>SO, thought I might struggle through the winter with a temporary
>ground or roof mount all band RADIAL-LESS (no room for radials!)
>vertical -- have read specs. on Cushcraft's R-7000+ (w/R-80 80 mtd.
>extra kit) -- 
>Any opinions?  Good or bad, pro or con -- NOTE that I have never
>used a vertical before but wish to use such a multi-band just to get by--

I've been using an R7000 for my primary antenna for 2 years.

It works OK. It does well on 40m, and works passibly on 20-10. I haven't 
used it much on the WARC bands. On 40m the low angle of radiation is 
evident. Of course, on 20 and higher it is not a beam. 

I have mine mounted on a 7.5 foot high on 1.5 inch rigid conduit. This 
isn't the best mast material. I recommend something with a larger outside 
diameter. a 2-inch OD mast would be perfect. 7.5 feet isn't an optimal 
hieght. Art (formerly with Cushcraft) told me the antenna was designed to 
be mounted about 18 feet high. Higher doesn't help, but lower than 8 feet 
can cause problems.

The usable bandwidth on 40m is kinda narrow. If you have an automatic 
antenna tuner, you'd never notice. I didn't opt for the R7000+ because a) 
I didn't want to put radials in - the 80m kit requries three 20 foot 
radials and b) it reduces the usable bandwidth.on 40m, and the 80m 
bandwidth is really small. 

I tried to tweak the tuning of my antenna, but found the interactions to 
be somewhat complex. Again, if you haven an automatic antenna tuner, I 
would just set it to the factory settings and leave it, except perhaps 
for the top 40m adjustment.

>Thanks for suggestions --
>If I was to use the R7000+, would you suggest ground post mounted 
>(on fence type support?) or roof top or at the top of 80 ft. tower??

A ground post would be fine, so long as it is about 10 feet tall or so. 
My 7.5 feet isn't quite optimal.

Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr@radio.org
Quote: "Not within a thousand years will man ever fly!"
            -- Wilbur Wright, 1901

FAQ on WWW:               http://www.contesting.com/towertalkfaq.html
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm