Cushcraft R-7000 Anyone had any experience?
Wayne & Kathy Stevenson
getting on HF.
Rob
multiband antenna to do a great job on all bands -- Such an antenna doesn't
exist!.
I have a R7000 (and posted many comments on it). I had lots of trouble
trying to get it to work okay. Then I found out that CUSHCRAFT redesigned
the antenna. CUSHCRAFT sent me a R7000TFK (Trap field replacement kit)
consisting of new traps and tubes.
The R7000 now works better but the SWR 2.0:1 Bandwidth is very small on 20
meters (less than 160kc much less than CUSHCRAFTS specs!). To boot if I
tune the R7000 for low SWR on CW portion of 20 meters, the R7000 is way out
of whack on 30 meters (since same adjustment affects both 20 and 30 meters).
The SWR bandwidth on 40 is also very small (but CUSHCRAFT admits this).
Other manufacturer's ads indirectly attack the R7000 by promising better
bandwidth on 20 and 40 meters.
Many people have complained about the 20 mtr trap burning out after running
400 watts or more. I can understand especially when the SWR on 20 mtrs can
be so high! With an antenna tuner, you can use the R7000 on all of 20
metres but DO NOT USE MORE THAN 100 watts out!
On 10, 12, 15 and 7 mtrs, the R7000 works great. I have worked lots of DX!
On 20 meters it is okay but I really hate the narrow bandwidth. On 30 and
40 meters it is okay but not great. (For a vertical to work well on 30/40
meters etc, in my view the length of the radiator must be larger than 24
feet!)
If you expect to operate on 20 meters most of the time, I suggest you buy
another antenna (other than a R7000) or just build a monoband vertical or
dipole.
If you expect to operate on 30/40 mtrs most of the time, I also suggest
another antenna (perhaps Butternut 40/80 meter vertical)
But if you really expect to operate on 10,12,15, and 17 meters most of the
time, try the R7000.. It is great!
Rob
"Wayne & Kathy Stevenson" <kwste...@wctel.net> wrote in message
news:383B69D8...@wctel.net...
Jim Kouzmanoff
usually run 1KW on 20 M without a problem. Works ok on 40 but I'd
rather have a dipole. 10/15 is great. Jim, K9KUZ
Rob
My R7000 (even with the new Trap Field Replacement Kit) is very narrow.
Only 160 kc (maybe 180kc on a good day hi) where swr is less than 2.0:1
73's
Rob
"Jim Kouzmanoff" <ji...@advancenet.net> wrote in message
news:3847f1f2...@news.advancenet.net...
KB1DWN
See http://www.eHam.net there is a full section on reviews of the R-7000
73's
Shashi KB1DWN (Also VU2ATO)
In article <3847f1f2...@news.advancenet.net>, ji...@advancenet.net says...
Richard Miner
Support to be very lacking. The high Q of the antenna makes it very
difficult to keep an acceptable SWR in all operating ranges.
73 de AB2AJ
Rob
I had lots of problems tuning. Then CUSHCRAFT came out with the Trap Field
replacement Kit with two new traps and new tubing. The spacing between the
traps have changed. Essentially CUSHCRAFT redesigned the antenna.
SWR is now below 2.0:1 on 10, 12, 15, 17 and 30 meters. On 20 it is still
narrow but much better. On 40 it is very narrow but CUSHCRAFT always stated
that it was narrow on that band.
My recommendation -- R7000 is a great antenna on 10, 12, 15, 17 and 30. But
if 20 and 40 meters are your bag, buy or build another antenna.
73'
Rob
"Richard Miner" <ab...@fcc.net> wrote in message
news:3848757A...@fcc.net...
Larry Gauthier
I purchased an R-7000 in March, and although my R-7000 seems to operate
according to specs, I am interested in the Trap Field Replacement Kit...
How do I call/notify/approach Cushcraft? Is this a freebie from CC? If not,
how much $$?
Thanks for the advice,
-larry gauthier
wb8bgo
Rob wrote in message ...
>What bands do you plan to operate most of the time?? Don't expect one
>multiband antenna to do a great job on all bands -- Such an antenna doesn't
>exist!.
>
>I have a R7000 (and posted many comments on it). I had lots of trouble
>trying to get it to work okay. Then I found out that CUSHCRAFT redesigned
>the antenna. CUSHCRAFT sent me a R7000TFK (Trap field replacement kit)
>consisting of new traps and tubes.
>
stuff deleted...
>
>Rob
>
>
>"Wayne & Kathy Stevenson" <kwste...@wctel.net> wrote in message
>news:383B69D8...@wctel.net...
Rob
If not, I would complain that they should provide it anyway- hi
In Canada, we must get kits, parts through our dealers. In the US, I think
you get your parts, kits direct from CUSHCRAFT. Send them an EMAIL.
You may have the newer R7000. If the recommended distance between the two
lower traps is 6 inches or so, you have the new R7000. In that case, you
don't have to worry about the kit.
Even with the kit, I had to cut my own piece if tubing since I needed about
8.5 inches spacing between the traps instead of the suggested 6 inches for
good SWR. The supplied 5 inch tubing to connect the traps was too short.
73's
Rob
"Larry Gauthier" <lar...@ismi.net> wrote in message
news:3849...@news.ismi.net...
stev...@my-deja.com
Cushcraft's specs, only to eventually (after 3 months of almost daily
calls to support) be told the antenna was redesigned, but the specs
were never updated. Then I had to seal the tubing above the traps to
prevent severe de-tuning and the loss of entire bands during
precipitation. That said, overall I like the antenna for what it is, a
24' multiband vertical. It performs very well on 10m-17m with ample
bandwidth. 20m-40m performance is slightly less than a dipole with
bandwidth close to a HamStick.
Another option (which I'm trying now) is an antenna coupler. I have an
SGC-230 with 120 feet of wire that gives me full 10m-160m capabilities.
No more bandwidth issues, and the 10m-40m performance is as good or
better than the R7000. 160m performance (using only 120' of wire) seems
fair to good, with s9+20dB reports at 300 miles with 100w. I can't
comment on 80m yet, but I expect good results. At $500, it's not a
cheap solution, but you will pay close to $400 for the R7000 and far
more for your time to install and tune it. Food for thought.
73's,
Steve
K1YZ
In article <9e024.195811$5r2.4...@tor-nn1.netcom.ca>,
> > > On Tue, 23 Nov 1999 23:30:16 -0500, Wayne & Kathy Stevenson
> > > <kwste...@wctel.net> wrote:
> > >
> > > >How well do these antenna work. I have limited space and am just
> > > >getting on HF.
> > > >
> >
>
>
Sent via Deja.com http://www.deja.com/
Before you buy.
Rob
Lots of fiddling around trying to tune it and see if I can come close to
CUSHCRAFTS specs. Then I was told by a dealer that CUSHCRAFT redesigned the
antenna and has a Trap Field Replacement Kit!
A few days before I found out from my dealer about the redesign, I talked to
Cushcraft. CUSHCRAFT NEVER EVEN mentioned the redesign and the new Trap
Field Replacement Kit! Talk about customer service!
After installing the Trap Field Replacement kit, the R7000 works very well
on 10-17 meters for DX. On 20 mtrs, it is still very narrow and is not that
great. On 30 and 40 is works okay but with a 24 foot radiator, you can't
expect the R7000 to be a great performer on 30 or 40 meters.
73's
Rob
<stev...@my-deja.com> wrote in message news:836ef3$oqo$1...@nnrp1.deja.com...
Leland Van Koten
years (ground mounted, but with a decent set of radials). I did work a
station near Perth, Australia, which is about as far from Baltimore as
you can get and still be on dry land -- and did it on 75 meters.
But after about 2 years, I put up an inverted vee which is a half wave
at 80 meters and fed it with ladder line through a tuner. Although it's
only about 35 feet at the feed point, and 20 feet or so on the ends,
after NUMEROUS on-air tests, the inverted vee outperformed the R-7000 at
least 95% of the time, often by a couple of S-units. This included 75
meters to Europe, on which by all rights the vertical should have done
better. Now, I use the vertical primarily to take a quick listen to a
band if I don't want to retune, and very rarely to see if it works when
I can't break into a pileup with the inverted vee.
You can buy a decent tuner and either homebrew or buy a multiband dipole
for less than an R7000. And to get decent bandwidth on 75/80 meters on
the R7000, you need a tuner anyway.
Lee, KE3FB
Rob
radiator is only 24 feet! With such a small radiator, the R7000+ is more
like a dummy load (with low SWR) than an effective radiator. on 40 and 75
meters. (Of course on 10-17 meters, the 24 foot radiator is great for DX)
If you put up a 1/4 or 1/2 wave full size vertical on 40 or 75 meters with a
good set of radials (or an elevated ground plane), it would without a doubt
outperform your inverted vee on 40 and 75 meters for DX by a long shot! Try
hanging a 40 meter 1/4 wave vertical from a tree with three or four elevated
radials. It will do wonders for DX!
Another great antenna for 40 and 75 meters is the vertical dipole (or a
sloping dipole). If you have a tower, you can put up four or five sloping
dipoles with 1/4 wave coax feeds to a coax switch box. The box will select
which dipole you want to use and leave the others unconnected. The
unconnected dipoles will act as reflectors. You will get 4 to 5 db gain
with a FB ratio of 15 db or so. A great antenna for 40 and 75 meters.
AMERITRON makes a great coax switch for this application.
73's
Rob
"Leland Van Koten" <vank...@home.com> wrote in message
news:38571736...@home.com...