On 21 May 2004 10:02:45 -0700, (Rick, K6RJ) wrote:

I don't know the answer to the main issue of this thread. I just
don't know enough about antennas to speak as an expert. However, as a
point of fact, the R7 manual does state on page 1 under the section
titled "Location":

Hi Rick,

Thank you for the follow-up. You are correct, and yes the pdf is a
poor, unsearchable copy as evidenced by your observations offered.

As far as this thread goes, I've seen testimony that it works/doesn't
work with radials - both ways. Such is the value of testimonials
where you can find any answer to suit any occasion.

I've seen testimonial "proof" that an eh works better than a standard
quarterwave, wherein the data clearly proved it didn't. The
testimonials dismissed the data (their own) as irrelevant.
Testimonial is fine and is occasionally called for. Testimonial as
proof is worthless.

I've offered data to this point of a "prohibition" on using radials.
The difference between 120 quarterwave or halfwave radials compared to
one short "counterpoise" barely tipped the meter at 1dB on the
performance side of the ledger. As for matching, I averred that
tuning may be impacted (I cannot imagine how it could be otherwise).
THAT is within the provence of Amateur radio service as a minimum
technical skill. THIS is a technical forum where design and data is
offered for examination. The remaining correspondence is confined to
the slow lane or the shoulder when a rhetorical axle is broken.

Frankly, this "prohibition" of no radials is more a design mandate,
not a papal bull. The site offered where we can find the actual
components of the "black box" displayed and laid out schematic style
offers an equal opportunity to redesign to allow radials. This
apparently is not within the skill-set of many, or arguably even
desired; however, it is not impossible (nor particularly difficult).

To this last point. I would offer that most of the interesting
correspondence (that isn't simply entertainment quality) is composed
of rather academic interests. Some of it is impractical in the
extreme and as absurd as fractals. More of it barely offers a
difference that would twitch an S Meter, or a Power meter. This does
not mean it lacks merit in its discussion because, let's face it, a
forum is built and survives on the vigor of debate. Clearly no one is
going to (legitimately) re-invent the dipole, so topics become rather
obtuse.

73's
Richard Clark, KB7QHC

David Browne wrote:

hi just got this ant,what is the best hight to mount this at,
there site says mount 8 feet, will it work better mounted 30 feet of ground
thanks dave browne


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Ok, I spoke to the designer this evening, and I'll pass on what I
learned. He was speaking fast, as he normally does, so I'm sure I
missed a lot. Roy can confirm that, and Roy can confirm that he handed
over another copy of his software to him just last week.

Per the designer

The R7 was built because he needed a multiband antenna in the fall of
90. The R5 was used as the base idea for the design. He worked on it
over late fall and winter 90/91. The antenna project was up and down 2
to 3 times a day at times.

The owner of Cushcraft heard of the backyard project in spring 1991, and
"asked" that it be brought to work. Tomorrow at the latest.

The antenna is not a half wave antenna, it is about a 3/8 wave antenna.
The impedance is approximately 250 ohms, and a roughly 4.5 to 1
transform is done. There is a series cap of 41 pF for 40m.

There are 7 radials of 49 inches, because Cushcraft had tons of 49 inch
5/8 whips for 2m. The R5 had 4, this needed more.

There is a false resonance on 75m or 80m, and if you put power into it
at that freq, you will burn up the matching system.

And, to end this argument, do not ever add radials to the system, and do
not remove any of the ones it comes with. It's a touchy match.

tom
K0TAR

Golly Gee -- what happened to the great R7 radial debate ??? (:-(

Not one single reply to the excellent post below -- guess it did end the
argument (:-)

Thanks for the post Tom
-------------------------------------------------------

"Tom Ring" wrote in message
Ok, I spoke to the designer this evening, and I'll pass on what I
learned. He was speaking fast, as he normally does, so I'm sure I
missed a lot. Roy can confirm that, and Roy can confirm that he handed
over another copy of his software to him just last week.

Per the designer

The R7 was built because he needed a multiband antenna in the fall of
90. The R5 was used as the base idea for the design. He worked on it
over late fall and winter 90/91. The antenna project was up and down 2
to 3 times a day at times.

The owner of Cushcraft heard of the backyard project in spring 1991, and
"asked" that it be brought to work. Tomorrow at the latest.

The antenna is not a half wave antenna, it is about a 3/8 wave antenna.
The impedance is approximately 250 ohms, and a roughly 4.5 to 1
transform is done. There is a series cap of 41 pF for 40m.

There are 7 radials of 49 inches, because Cushcraft had tons of 49 inch
5/8 whips for 2m. The R5 had 4, this needed more.

There is a false resonance on 75m or 80m, and if you put power into it
at that freq, you will burn up the matching system.

And, to end this argument, do not ever add radials to the system, and do
not remove any of the ones it comes with. It's a touchy match.

tom
K0TAR

On Sun, 23 May 2004 08:14:41 -0700, "Keyboard In The Noise"
wrote:

Golly Gee -- what happened to the great R7 radial debate ??? (:-(

Not one single reply to the excellent post below -- guess it did end the
argument (:-)

Well, I found it interesting that the R7 is a 3/8 wave antenna, not a
1/2-waver. Which means radials might work as well as those 2-meter
whips/decouplers sticking out at the base.

Funny, I've never seen Cushcraft refer in their ads to their designs
being "1/2 wave." Maybe that's just a myth somebody started...

Bob
k5qwg



Thanks for the post Tom
-------------------------------------------------------

"Tom Ring" wrote in message
Ok, I spoke to the designer this evening, and I'll pass on what I
learned. He was speaking fast, as he normally does, so I'm sure I
missed a lot. Roy can confirm that, and Roy can confirm that he handed
over another copy of his software to him just last week.

Per the designer

The R7 was built because he needed a multiband antenna in the fall of
90. The R5 was used as the base idea for the design. He worked on it
over late fall and winter 90/91. The antenna project was up and down 2
to 3 times a day at times.

The owner of Cushcraft heard of the backyard project in spring 1991, and
"asked" that it be brought to work. Tomorrow at the latest.

The antenna is not a half wave antenna, it is about a 3/8 wave antenna.
The impedance is approximately 250 ohms, and a roughly 4.5 to 1
transform is done. There is a series cap of 41 pF for 40m.

There are 7 radials of 49 inches, because Cushcraft had tons of 49 inch
5/8 whips for 2m. The R5 had 4, this needed more.

There is a false resonance on 75m or 80m, and if you put power into it
at that freq, you will burn up the matching system.

And, to end this argument, do not ever add radials to the system, and do
not remove any of the ones it comes with. It's a touchy match.

tom
K0TAR

Hi Bob -- see URL:
http://www.cushcraft.com/support/pdf/r5.pdf

Sez -- "Your R5 is a half wavelength vertical which does not require
traditional ground radials"
--
Keyboard In The Noise

Opinions are the cheapest commodities in the world. Author unknown but
"right on"
--------------------------------------------------
"Bob Miller" wrote in message
...


Funny, I've never seen Cushcraft refer in their ads to their designs
being "1/2 wave." Maybe that's just a myth somebody started...

Bob
k5qwg