On 9/10/2012 9:01 PM, Ralph Mowery wrote:
wrote in message
...

If they rated a ringo using dbd, it would be zero.. Which doesn't
look too good in the ad's.. :|
So they use dbi to make for manlier gain figures..


I think CC just pulled numbers out of the air. Especially in the eairly
days. Just looking at an old ad from 1974. They rate the 2 meter Ringo at
3.75 db gain. No refferance as to what.

Also the 11 element was rated at
13.2 db of gain.

Which was quite a bit shorter than the CC 214WB. The 214WB, which was
better when you took off the marketing based "trigonal" reflector, still
only made 11.91 dBd on a 14' 11" boom when optimized (based on your
preferences).

BTW the maximum reasonably obtainable gain on a yagi with a boom greater
than 1 wavelngth is predictable with the following equation -

G = 10 log (5.4075 B + 4.25) for B GT 1

Where G is gain in dBd and B is boomlength in wavelengths.

I worked this out in the early 90's from a database of over 100 of the
best practical, buildable VHF/UHF yagi designs. Thanks especially to
K1FO for all of his design work. His 432 yagis had the greatest effect
on the numbers. W1JR thinks it's accurate, so who am I to argue?

I designed an extended version of the 214 that lets you re-use the
useless extra reflectors as directors. This had a 17' 7" boom and would
make 12.43 dBd at 144.2 with a decent feedpoint impedance of 21 ohms and
F/B of 24 dB. This was used successfully at a friend's place for a 2 by
2 EME array. The antenna was tested at Central States and met the
computer predicted gain exactly.

If you want crazy I have a 432 EME antenna that does 18.4 dBd (according
to the model) which tested at 18.1 on the range. They said the range
was too short to test the antenna. It was still the highest gain for a
homebrew 432 ever tested at Central States.

Anyone that wants any 6m to 70cm designs can drop me an email. I've got
lots.

tom
K0TAR

"tom" wrote in message
. net...
I worked this out in the early 90's from a database of over 100 of the
best practical, buildable VHF/UHF yagi designs. Thanks especially to K1FO
for all of his design work. His 432 yagis had the greatest effect on the
numbers. W1JR thinks it's accurate, so who am I to argue?

I like the K1FO designs. I had a 432 antenna by Rutland Arays that seemed
to be a copy of the K1FO design. Several years ago I put up some new
antennas and wanted to go withthe Rutland, but he had passed away and went
with the M-Square antennas for 2 meters and 432 mhz.

From what I read, the Trigonal reflector was something that looked good for
sells, but did little or nothing for that antenna.

On 9/10/2012 7:40 PM, Channel Jumper wrote:
Being Long or Short is not the problem - if it was simple vertical with
a ground plane with no loading coil - like a whip on a automobile - yes
- you would be right.

No problem even with loading coils. Or when using the various
matching systems. They all act fairly predictably.


But when dealing with a Ringo - which uses a ring to adjust the
capacitive / inductive and also uses a tuning stub match - each part of
the antenna works against each other..

Even now, the antenna on the VSWR Bridge shows a 2:1 match!

Sure, it needs more inductance.

But I figure the Ring is probably 9 inches too shot - if the ring is 7.5
inches in diameter and needs to be 10 and the stub is too short - if it
needs to be 18 inches long and is only 6....

For a 10m ringo 18 inches would be about right with it tapped
about halfway. I think one I made used about a 20 inch dia turn.
But I didn't need all of it.


The Antenna Analyzer would tell me the Resistive / Reactive components
and all I would have to do is match them and it would work on any one
frequency.

Sure.. But I can do it by sense of smell.. Plenty of practice.. :/


This is the problem with the Ringo - why it is not broad banded.
The main use where I live was by people who were installers of LMRS
equipment that sold them along with a radio to fire companies and
ambulances....


It should have about the same bandwidth as most any other
half wave. I've never noticed them to really show any less
bandwidth than other designs. But then again, I'm not sure
what you mean by not broad banded. That could vary depending
on expectations.

On 9/10/2012 10:33 PM, Ralph Mowery wrote:


From what I read, the Trigonal reflector was something that looked good for
sells, but did little or nothing for that antenna.




Yep, most have come to the conclusion they were kind of a waste
of metal.. I've got an old 2m "boomer" that has that reflector..

In article ,
Channel Jumper wrote:

But I figure the Ring is probably 9 inches too shot - if the ring is 7.5
inches in diameter and needs to be 10 and the stub is too short - if it
needs to be 18 inches long and is only 6....

Channel Jumper-

You can get parts measurements for the various Ringo antennas at the
CushCraft website (Now part of MFJ!). For the Ten Meter version,
http://www.cushcraftamateur.com/Product.php?productid=AR-10. A user
manual is available by clicking on "AR-10 Downloads". I do not see a
Stub length given for the AR-10, but the AR-6 manual has a chart.

The AR-10 manual's specification says that gain is 3 dB "Ref.
Quarterwave"!

Fred
K4DII

On 9/12/2012 7:12 PM, Fred McKenzie wrote:
In article ,
Channel Jumper wrote:

But I figure the Ring is probably 9 inches too shot - if the ring is 7.5
inches in diameter and needs to be 10 and the stub is too short - if it
needs to be 18 inches long and is only 6....

Channel Jumper-

You can get parts measurements for the various Ringo antennas at the
CushCraft website (Now part of MFJ!). For the Ten Meter version,
http://www.cushcraftamateur.com/Product.php?productid=AR-10. A user
manual is available by clicking on "AR-10 Downloads". I do not see a
Stub length given for the AR-10, but the AR-6 manual has a chart.

It's in the manual.. Was about 16.5 inches long with the RG-8
they use. They don't give the dia for the single turn coil,
but I've built a few of those, and used 18-20 inches or so dia.
Not real critical being it will be tapped appx mid way for a coil
that diameter. 7.5 inches dia is too small for 10m. Even 10 inches
would likely be too small unless maybe you tapped it near the end,
using almost the whole coil. I don't think I'd make it any less
that 15-16 inches dia.

In article , NM5K wrote:

On 9/12/2012 7:12 PM, Fred McKenzie wrote:
In article ,
Channel Jumper wrote:

But I figure the Ring is probably 9 inches too shot - if the ring is 7.5
inches in diameter and needs to be 10 and the stub is too short - if it
needs to be 18 inches long and is only 6....

Channel Jumper-

You can get parts measurements for the various Ringo antennas at the
CushCraft website (Now part of MFJ!). For the Ten Meter version,
http://www.cushcraftamateur.com/Product.php?productid=AR-10. A user
manual is available by clicking on "AR-10 Downloads". I do not see a
Stub length given for the AR-10, but the AR-6 manual has a chart.

It's in the manual.. Was about 16.5 inches long with the RG-8
they use. They don't give the dia for the single turn coil,
but I've built a few of those, and used 18-20 inches or so dia.
Not real critical being it will be tapped appx mid way for a coil
that diameter. 7.5 inches dia is too small for 10m. Even 10 inches
would likely be too small unless maybe you tapped it near the end,
using almost the whole coil. I don't think I'd make it any less
that 15-16 inches dia.

I overlooked the stub in the manual I downloaded. Now I see it in the
Ring Assembly Parts, Key FF. It is 16 5/8".

Ring diameter is listed as 13" in a chart at the web link above. I do
not see size listed in the manual, where the ring is shown as two
similar pieces bolted together.

Fred
K4DII

On 9/13/2012 12:01 AM, Fred McKenzie wrote:


It's in the manual.. Was about 16.5 inches long with the RG-8
they use. They don't give the dia for the single turn coil,
but I've built a few of those, and used 18-20 inches or so dia.
Not real critical being it will be tapped appx mid way for a coil
that diameter. 7.5 inches dia is too small for 10m. Even 10 inches
would likely be too small unless maybe you tapped it near the end,
using almost the whole coil. I don't think I'd make it any less
that 15-16 inches dia.

I overlooked the stub in the manual I downloaded. Now I see it in the
Ring Assembly Parts, Key FF. It is 16 5/8".

Ring diameter is listed as 13" in a chart at the web link above. I do
not see size listed in the manual, where the ring is shown as two
similar pieces bolted together.

Fred
K4DII


Yep, I see it now.. I was thinking it was slightly larger than that,
but maybe the original AR-10 I had was only 13 inches across.
They show the 6m version using the same part.. From the diagram,
it looks like about 2/3 of the turn is used on 10m.
Also, if I remember right, the 6m version used no coax cap for
tuning. I was looking at the 6m ringo PDF the other day.

"Channel Jumper" ha scritto nel
messaggio ...
Any idea's?
Ringo antenna - like *all* half wave antennas - don't want the mounting mast
lenght of 1/4 wl and odd multiples. So be careful. Many people said ringo
antenna is bad, no resonance, etc... because of this.

Chris -.-. --.-

Ok, so what I did was take the antenna apart, add another couple of feet and made it 16' long.
I shorted out the stub match at 19 inches long.

SWR was about 5:1

So I tried lengthening it to 18' - which did not improve the SWR much.

So I put it back at 16' and I cut the stub match off at the solder point and I stuck it up 30' in the air and the SWR was 1.1 : 1 at channel 23 and was 1.25 : 1 on channel 1 and was 1 : 1 on channel 19....

Since the person I put it up for only has a 23 channel radio, and since he only uses channel 19 - that was all he cared about...

Technicially it says it is good for about 1.5 : 1 on any frequency - hence getting it closer then that was a real accomplishment, and although I know a little about antenna's - this one had me stumpped..... Thanks everyone.....