A Radio forum. RadioBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » RadioBanter forum » rec.radio.amateur » Antenna
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Experience with Cushcraft R7 vertical HF antenna?



 
 
Thread Tools Display Modes
  #1  
Old April 15th 04, 10:26 PM
f=lbo=rn
Guest
 
Posts: n/a
Default Experience with Cushcraft R7 vertical HF antenna?

Hi,

I'm wondering if anybody else made some experiences (good or bad) with
the R7 cushcraft vertical antenna. I bought such an antenna second-hand
some days ago, but never used a vertical antenna for HF before.

vy 73 de Lorenz
--
Fritz Lorenz Born, HB9DTN
E-Mail: f=lbo=rn@sw=iss=onli=ne.=ch
-- sed 2,4s/=//g signature "I hate spam!!"
  #2  
Old April 15th 04, 11:00 PM
JGBOYLES
Guest
 
Posts: n/a
Default

I'm wondering if anybody else made some experiences (good or bad) with
the R7 cushcraft vertical antenna


Hi Lorenz. The R7 will work, needs a ground radial system to work well, and
will be difficult to get a good match on multibands. Never used one myself,
just commenting on multiband verticals in general that I have used.
73 Gary N4AST
  #3  
Old April 15th 04, 11:37 PM
'Doc
Guest
 
Posts: n/a
Default

Fritz,
I have an R-7 currently laying in the yard. I'm not
a big vertical fan, but have to say that it did work as
advertised. Unfortunately, the fibreglass insulator used
to hold the antenna on the 'base' doesn't last forever if
it's in the sun very much (mine was).
It wasn't really all that hard to tune, just follow the
recomendations. Don't expect much bandwidth on 40 meters!
It's also fairly sensitive to 'where/how' you mount it.
I tuned mine on a fence post, then tried to move it to the
top of my house. Worked great on the post, terrible on the
roof. Too lazy to re-tune, so just mounted it on the post.
Still not a vertical fan, but I think I got my money's
worth out of the R-7 (10-15 years?).
'Doc
  #4  
Old April 16th 04, 12:03 AM
Irv Finkleman
Guest
 
Posts: n/a
Default

f=lbo=rn wrote:

Hi,

I'm wondering if anybody else made some experiences (good or bad) with
the R7 cushcraft vertical antenna. I bought such an antenna second-hand
some days ago, but never used a vertical antenna for HF before.

vy 73 de Lorenz
--
Fritz Lorenz Born, HB9DTN
E-Mail: f=lbo=rn@sw=iss=onli=ne.=ch
-- sed 2,4s/=//g signature "I hate spam!!"


I picked one up used. I checked out all the mechanical
connections in the traps, then set it up according to instructions manual
and am terribly pleased with it. I did arrange for the 40 meters to
be set to the low end where I operate, other than that, I get great
results with it using QRP. If you do a Google search you will find that
some people have experienced problems, but nothing that can't be fixed
using the information available on the net. I have mine sitting on a
12 foot piece of pipe just to lift the radials over the garage roof.

Irv VE6BP
--
--------------------------------------
Diagnosed Type II Diabetes March 5 2001
Beating it with diet and exercise!
297/215/210 (to be revised lower)
58"/43"(!)/44" (already lower too!)
--------------------------------------
Visit my HomePage at http://members.shaw.ca/finkirv/
Visit my very special website at http://members.shaw.ca/finkirv4/
Visit my CFSRS/CFIOG ONLINE OLDTIMERS website at http://members.shaw.ca/finkirv5/
--------------------
Irv Finkleman,
Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP
Calgary, Alberta, Canada
  #5  
Old April 16th 04, 12:22 AM
Incognito
Guest
 
Posts: n/a
Default

Well the R7 Cushcraft antenna is NOT your Fathers quarter wave vertical --
it is a half wave end fed antenna thus it needs no radials. It is fed at a
high impedance point by virtue of the matching black box at the antenna
feedpoint.

In fact the addition of radials will really screw it up --- read the manual
see URL:
http://www.cushcraft.com/support/pdf/r7.pdf
"THE R7 SHOULD NOT BE CONNECTED TO A GROUND RADIAL SYSTEM".
I ignored this (as an experiment) and found Cushcraft knew what they were
talking about.

The four 49 inch rods at the antenna bottom are counterpoises designed to
isolate the antenna from ground and not long enough to be resonant on any
band.

The bandwidth and efficiency on 40M, I found to be poor. But it works well
enough on the other bands, covering full bandwidth on all bands except 40M
and 20M. You will have to choose the portion of the band you want to operate
on for these two bands.

Tuning the R7 was easy, following the manual instructions.

Be careful of running high power into this antenna for an extended length of
time -- particularly if you horse it beyond resonance with a tuner --
several here have frazzled the traps when doing this.

Using an R7 I was able to work a lot of DX, it does seem to have a low angle
of radiation -- Cushcraft claims 16 degrees.

For more opinions --see url:
http://www.eham.net/reviews/detail/518

This opinion is not to engage in a debate of 1/4 wave vs 1/2 wave verticals
save that for another thread.
--
Incognito By Necessity (:-(

If you can't convince them, confuse them.
- - -Harry S Truman




"JGBOYLES" wrote in message
...
I'm wondering if anybody else made some experiences (good or bad) with
the R7 cushcraft vertical antenna


Hi Lorenz. The R7 will work, needs a ground radial system to work well,

and
will be difficult to get a good match on multibands. Never used one

myself,
just commenting on multiband verticals in general that I have used.
73 Gary N4AST



  #6  
Old April 16th 04, 12:22 AM
Incognito
Guest
 
Posts: n/a
Default

Well the R7 Cushcraft antenna is NOT your Fathers quarter wave vertical --
it is a half wave end fed antenna thus it needs no radials. It is fed at a
high impedance point by virtue of the matching black box at the antenna
feedpoint.

In fact the addition of radials will really screw it up --- read the manual
see URL:
http://www.cushcraft.com/support/pdf/r7.pdf
"THE R7 SHOULD NOT BE CONNECTED TO A GROUND RADIAL SYSTEM".
I ignored this (as an experiment) and found Cushcraft knew what they were
talking about.

The four 49 inch rods at the antenna bottom are counterpoises designed to
isolate the antenna from ground and not long enough to be resonant on any
band.

The bandwidth and efficiency on 40M, I found to be poor. But it works well
enough on the other bands, covering full bandwidth on all bands except 40M
and 20M. You will have to choose the portion of the band you want to operate
on for these two bands.

Tuning the R7 was easy, following the manual instructions.

Be careful of running high power into this antenna for an extended length of
time -- particularly if you horse it beyond resonance with a tuner --
several here have frazzled the traps when doing this.

Using an R7 I was able to work a lot of DX, it does seem to have a low angle
of radiation -- Cushcraft claims 16 degrees.

For more opinions --see url:
http://www.eham.net/reviews/detail/518

This opinion is not to engage in a debate of 1/4 wave vs 1/2 wave verticals
save that for another thread.
--
Incognito By Necessity (:-(

If you can't convince them, confuse them.
- - -Harry S Truman




"JGBOYLES" wrote in message
...
I'm wondering if anybody else made some experiences (good or bad) with
the R7 cushcraft vertical antenna


Hi Lorenz. The R7 will work, needs a ground radial system to work well,

and
will be difficult to get a good match on multibands. Never used one

myself,
just commenting on multiband verticals in general that I have used.
73 Gary N4AST



  #7  
Old April 22nd 04, 03:00 PM
JDer8745
Guest
 
Posts: n/a
Default

I have used one for many years, right after it first came out. NO PROBLEMS. I
have it on a telescoping TV mast. The bottom of it is about 20 feet up.

On 40 it is adjusted for CW portion, and use built-in AT in rigs for a match
there.

Elsewhere it has acceptable SWR for each band.

73 de Jack, K9CUN
  #8  
Old April 22nd 04, 03:44 PM
Jean-Guy
Guest
 
Posts: n/a
Default

Same here, have had mine up and going after fixing it last summer, went thru
winter very well, not a sign of detoriation at all. Still works like a top.
Now I don't know if anyone else did check the antenna with an antenna tuner
(mfj 259 or whichever)
Did check mine out last year will doing the installation and found the
antenna to resonant not to badly at all on 6 meters, and also on 80, where
it would be a real compromise antenna. A bit hight on swr , but in a pinch i
am sure it could be use with a tuner on at least 80 meters. Someday will
check it out on the air on 80 meters to really find out what is what with
it.

Just some feedback about R-7.

de Jean-Guy/ve9buf


"JDer8745" a écrit dans le message de
...
I have used one for many years, right after it first came out. NO

PROBLEMS. I
have it on a telescoping TV mast. The bottom of it is about 20 feet up.

On 40 it is adjusted for CW portion, and use built-in AT in rigs for a

match
there.

Elsewhere it has acceptable SWR for each band.

73 de Jack, K9CUN



 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Inverted ground plane antenna: compared with normal GP and low dipole. Serge Stroobandt, ON4BAA Antenna 8 February 24th 11 10:22 PM
Poor quality low + High TV channels? How much dB in Preamp? lbbs Antenna 16 December 13th 03 03:01 PM
FS: Cushcraft MA5V Ham Radio Vertical antenna David Hawkins Antenna 0 November 15th 03 12:49 PM
QST Article: An Easy to Build, Dual-Band Collinear Antenna Serge Stroobandt, ON4BAA Antenna 12 October 16th 03 07:44 PM


All times are GMT +1. The time now is 02:57 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ©2004-2014 RadioBanter.
The comments are property of their posters.