On 9 juin, 17:27, "Jerry" wrote:
wrote in message

...
On 9 juin, 15:18, "Jerry" wrote:





wrote in message

....
On 7 juin, 16:45, "Jerry" wrote:

wrote in message

....
On 6 juin, 22:15, "Jerry" wrote:

"Rich Griffiths" wrote in message

xcommunications...

snip

hi "jerry"

i want QHA models and i try to adapt them for 2GHZ it's for
heliosynchron
satellite for earth sensing
thank u

Hi "disc"

Wow, thats a small Quad Helix. Tell me the dimensions. I'll try to
model
it for you using EZNEC.
Is this a real project? That is, do you have the antenna, or are
you
planning to build one? If you have a "store bought" 2 GHz Quad
helix,
there are certainly some patterns available from the mnanufacturer.
If
you plan to build the Quad helix, are you able to make any
impedance
measurements of the model?
As you know, the fundamental plan in the Quad Helix design is to
make
one
loop radiate 90 degrees later than the other due to the impedance
difference between the two loops.

Jerry KD6JDJ

Remember that gigahertz-level quad helixes used on satellites are
usually
multiturn devices. Model results for a 137-MHz, half-turn antenna
scaled
up to 2 GHz may not be appropriate.

... Rich W2RG

Hi Rich

Your comment helps. I wasnt aware that multiturn Quad Helix antennas
were used on satellites. can you point me to a site where the
multiturn
Quad Helix is used for satellite application?

Thanks
Jerry KD6JDJ- Masquer le texte des messages précédents -

- Afficher le texte des messages précédents -

hi jerry

follow this links please :

http://www.sstl.org/assets/Downloads...x%20Antenna.pd....

discretman16

Hi discreteman16

I couldnt figure out how to see the referenced sites without paying
$31.50. But, that looks like a site where extensive computer modeling
has
been documented. It becomes quite obvious that I am at a far too low
level
in my math and theoritical capability to assist you. I dont even know
what
ANSOFT and matlab are. But, I use EZNEC to describe Quad Helix antennas
of my design. It takes me less than 10 minutes to describe a Quad Helix
in EZNEC. I strongly recommend EZNEC to any young person who has *any*
interest in designing or understanding antennas. It is a great tool for
anyone who is interested in antennas. If I can be of any help to you by
trying to model a Quad Helix for you, you are welcome to contact me.

Jerry KD6JDJ- Masquer le texte des messages précédents -

- Afficher le texte des messages précédents -

hi jerry
i'm surprised when u tell me that u dont know what's
matlab !!!!!!!!!!!!!!,www.mathworks.com
i know that the NEC is the most used in antennas modeling, but it
takes me several days to learn hiw i use it,
if u give some tutorials it will be good, i downloaded the demo
version and i found it good and difficul to use!!!!!!!!!

thank u

Hi discreteman16

I appreciate the fact that you could be surprized about my ignoirance.
But, I am an old "handyman" kind of guy who likes to play with antennas..
The last time I worked as an antenna design engineer was in 1969.

I'd be happy to assist you with simple antenna modeling with EZNEC.
There are very few EZNEC users who know less about antenna modeling than I
do. It is my belief that 'if I can learn EZNEC, anyone can'.

If you intend to model a Quad Helix with EZNEC, it is necessary to
purchase the version that configures a helix with a "stroke of the
keyboard".

Send me the dimensions and frequency of your Quad Helix and I'll model it
for you. I'll try to keep a record of the time required.

Jerry KD6JDJ- Masquer le texte des messages précédents -

- Afficher le texte des messages précédents -

hi jerry

frequency * * * * *= 2025-2110 MHz uplink or 2200 -2290 MHz downlink
number of turns = usually 2
radius * * * * * * * = 1 to 3 inch

good luck for therecord and thank u

Hi disc

* I made a first approximation of a 2.2 GHz Quad Helix. *It came out as a
2.274 GHz Quad Helix. *It is about 40 mm tall and 20 mm wide. * It took me
about 45 minutes mainly because I chased a few mistakes.

* Contact me again via my E-mail for any additional info. * Tell me what
wire diameter you prefer.

* I had difficulty trying to open the file you sent. * My computer skills
are really poor.

* * * * * *Jerry- Masquer le texte des messages précédents -

- Afficher le texte des messages précédents -

ok jerry, i try to find more information about the antenna

On 9 juin, 17:27, "Jerry" wrote:
wrote in message

...
On 9 juin, 15:18, "Jerry" wrote:





wrote in message

....
On 7 juin, 16:45, "Jerry" wrote:

wrote in message

....
On 6 juin, 22:15, "Jerry" wrote:

"Rich Griffiths" wrote in message

xcommunications...

snip

hi "jerry"

i want QHA models and i try to adapt them for 2GHZ it's for
heliosynchron
satellite for earth sensing
thank u

Hi "disc"

Wow, thats a small Quad Helix. Tell me the dimensions. I'll try to
model
it for you using EZNEC.
Is this a real project? That is, do you have the antenna, or are
you
planning to build one? If you have a "store bought" 2 GHz Quad
helix,
there are certainly some patterns available from the mnanufacturer.
If
you plan to build the Quad helix, are you able to make any
impedance
measurements of the model?
As you know, the fundamental plan in the Quad Helix design is to
make
one
loop radiate 90 degrees later than the other due to the impedance
difference between the two loops.

Jerry KD6JDJ

Remember that gigahertz-level quad helixes used on satellites are
usually
multiturn devices. Model results for a 137-MHz, half-turn antenna
scaled
up to 2 GHz may not be appropriate.

... Rich W2RG

Hi Rich

Your comment helps. I wasnt aware that multiturn Quad Helix antennas
were used on satellites. can you point me to a site where the
multiturn
Quad Helix is used for satellite application?

Thanks
Jerry KD6JDJ- Masquer le texte des messages précédents -

- Afficher le texte des messages précédents -

hi jerry

follow this links please :

http://www.sstl.org/assets/Downloads...x%20Antenna.pd....

discretman16

Hi discreteman16

I couldnt figure out how to see the referenced sites without paying
$31.50. But, that looks like a site where extensive computer modeling
has
been documented. It becomes quite obvious that I am at a far too low
level
in my math and theoritical capability to assist you. I dont even know
what
ANSOFT and matlab are. But, I use EZNEC to describe Quad Helix antennas
of my design. It takes me less than 10 minutes to describe a Quad Helix
in EZNEC. I strongly recommend EZNEC to any young person who has *any*
interest in designing or understanding antennas. It is a great tool for
anyone who is interested in antennas. If I can be of any help to you by
trying to model a Quad Helix for you, you are welcome to contact me.

Jerry KD6JDJ- Masquer le texte des messages précédents -

- Afficher le texte des messages précédents -

hi jerry
i'm surprised when u tell me that u dont know what's
matlab !!!!!!!!!!!!!!,www.mathworks.com
i know that the NEC is the most used in antennas modeling, but it
takes me several days to learn hiw i use it,
if u give some tutorials it will be good, i downloaded the demo
version and i found it good and difficul to use!!!!!!!!!

thank u

Hi discreteman16

I appreciate the fact that you could be surprized about my ignoirance.
But, I am an old "handyman" kind of guy who likes to play with antennas..
The last time I worked as an antenna design engineer was in 1969.

I'd be happy to assist you with simple antenna modeling with EZNEC.
There are very few EZNEC users who know less about antenna modeling than I
do. It is my belief that 'if I can learn EZNEC, anyone can'.

If you intend to model a Quad Helix with EZNEC, it is necessary to
purchase the version that configures a helix with a "stroke of the
keyboard".

Send me the dimensions and frequency of your Quad Helix and I'll model it
for you. I'll try to keep a record of the time required.

Jerry KD6JDJ- Masquer le texte des messages précédents -

- Afficher le texte des messages précédents -

hi jerry

frequency * * * * *= 2025-2110 MHz uplink or 2200 -2290 MHz downlink
number of turns = usually 2
radius * * * * * * * = 1 to 3 inch

good luck for therecord and thank u

Hi disc

* I made a first approximation of a 2.2 GHz Quad Helix. *It came out as a
2.274 GHz Quad Helix. *It is about 40 mm tall and 20 mm wide. * It took me
about 45 minutes mainly because I chased a few mistakes.

* Contact me again via my E-mail for any additional info. * Tell me what
wire diameter you prefer.

* I had difficulty trying to open the file you sent. * My computer skills
are really poor.

* * * * * *Jerry- Masquer le texte des messages précédents -

- Afficher le texte des messages précédents -

hi jerry
u have to use the acrobat reader www.adobe.com/fr/products/reader/