[TenTec] R7000 Vertical Experience

[Peter A. Klein]

Bernie, K5XS asks:

> Has anyone used the R-7000 vertical?  I'm generally not a vertical kinda
> guy, but have a need for something protable to take out in the boonies
> with my Boy Scout troop (and the Omni) and am considering the R-7000. 

I have an R7, the R-7000's older brother.  I also have the proverbial
"inverted vee in a tree," 35' up, about 100' long, and fed with TV
twinlead and a tuner.  Sort of a G5RV without the coax :-)  I have never
run more than 100 watts. 

The R7 is *sometimes* better for long-haul DX by an S-unit, rarely by 2
S-units.  Often, there's no difference.  In that case, I will use the vee
because it's less noisy on receive. On 20m, the vee is often better,
perhaps because I get a little gain and some kind of cloverleaf pattern.
On 15 and 10, the R7 is usually better, and broad enough not to need
tuning except at the edges.  On 40, as you'd expect, the R7 is better for
DX, though not great, and the vee is better for domestic contacts.

Yes, you can take the R7 apart and transport it easily, but it's not all
that easy to assemble (2 people recommended).  Also, unless you mount it 8
feet above ground, the measurements in the manual will be a bit off, and
you'll have to tune by trial and error. 

As others have mentioned, if I was going out into the woods, I'd take
along a 40 meter dipole fed with twinlead or ladder line, and a slingshot,
fishing rod, or a companion with a good arm.  Rocks can be purchased
locally. :-) 

One good trick for low-angle radiation is to mount such a dipole
vertically, keeping the low end several feet off the ground, and the
feedline running away from the antenna at as close to right angles as
possible.  Yes purists, it's unbalanced, but its a better performer than a
no-radial vertical, and perhaps better than a 3 or 4 radial "ground
plane."  And it's easier to put up in a tree--just one high support does
it.

I have never had the trap burnout problems some people have mentioned.
A Cushcraft tech told me that some of the burnout problems are caused by
people trying to load the R7 up on 80m with a tuner(!)  I have heard about
the burnout problems from others, though.  The general consesus is that
it's a barefoot antenna only.

--Peter (KD7MW)

Peter A. Klein  (pklein@seattleu.edu)  :    -----==3==      ---      ---
Network Administrator, LAN/WAN/Novell  :   |    |  |  |    |   |    |   |
Seattle University, 296-5569           :  @|   @| @| @|   @|  @|   @|  @|




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