RadioBanter

RadioBanter (https://www.radiobanter.com/)
-   Antenna (https://www.radiobanter.com/antenna/)
-   -   Big Wheel plans (https://www.radiobanter.com/antenna/111141-big-wheel-plans.html)

Tom Ring December 8th 06 03:20 AM

Big Wheel plans
 

I've done a fair bit of googling, and haven't found a decent set of
plans to construct a 2m Big Wheel. I have found the original article
from 1961, but the resolution in the pdf is lousy.

Anyone have a link?

tom
K0TAR

Jerry Martes December 8th 06 04:01 AM

Big Wheel plans
 

"Tom Ring" wrote in message
.. .

I've done a fair bit of googling, and haven't found a decent set of plans
to construct a 2m Big Wheel. I have found the original article from 1961,
but the resolution in the pdf is lousy.

Anyone have a link?

tom
K0TAR


Hi Tom

I downloaded the 4 pages. Yeah, they are a bit difficult to read, but all
the informationis readable. If there is any particular part that interests
you, I can (hopefully) check to see if it is readable here.

I'll be curious to learn the advantage of this antenna.

Jerry



[email protected] December 8th 06 04:04 AM

Big Wheel plans
 
Made a sketch from Tenth Ed. ARRL antenna book ... gotta love the used
bookstore

http://www.n3ox.net/files/bigwheel_sketch.pdf

All red circles go to one side of the feedline, all blue go to the
other.

Impedance if the antenna is resonant is apparently about 12 ohms,
suggested matching method is to make each element a little bit short so
that it's a bit capacitive at the desired center frequency and then use
a hairpin inductor to match to 50 ohms.

No details on specific lengths in my book here; just says that each
element is "one wavelength" ... If I'm calculating correctly, think
that you want to shorten the elements enough that the natural feedpoint
impedance of the three paralleled elements is about 12-j21 and then use
a hairpin inductor of about +j28 ohms as the shunt across the
feedpoint.

Dan


[email protected] December 8th 06 04:05 AM

Big Wheel plans
 
Horizontal omni with gain... was gonna build one for 6m until I
realized how big it was :-)


[email protected] December 8th 06 04:27 AM

Big Wheel plans
 
Actually, maybe it doesn't have gain compared to a halo... I'm not
really sure... I have an inconclusive 6m Big Wheel EZNEC model with an
average gain problem... though at this point it's only showing a -0.5dB
average gain or so, and impedance and gain seem constant with
segmentation changes, so it's probably not so bad.

I made it back when I was considering building one and modified it a
little bit to make the avg. gain work out better.

Anyway, if anyone wants to try to get it to work reliably, there's a
model at

http://www.n3ox.net/projects/eznec/6mBigWheel.ez

Dan


Dale Parfitt December 8th 06 04:33 AM

Big Wheel plans
 

wrote in message
ups.com...
Actually, maybe it doesn't have gain compared to a halo... I'm not
really sure... I have an inconclusive 6m Big Wheel EZNEC model with an
average gain problem... though at this point it's only showing a -0.5dB
average gain or so, and impedance and gain seem constant with
segmentation changes, so it's probably not so bad.

I made it back when I was considering building one and modified it a
little bit to make the avg. gain work out better.

Anyway, if anyone wants to try to get it to work reliably, there's a
model at

http://www.n3ox.net/projects/eznec/6mBigWheel.ez

Dan


Hi Dan,
A model I did some years back showed gain very close to a dipole, much
better omni pattern than classic halo/loops and about a dB better gain than
the loops (once you average their gain around the full 360 azimuth).
This from memory.
Dale W4OP




Owen Duffy December 8th 06 04:59 AM

Big Wheel plans
 
On 7 Dec 2006 20:27:37 -0800, "
wrote:

Actually, maybe it doesn't have gain compared to a halo... I'm not
really sure... I have an inconclusive 6m Big Wheel EZNEC model with an
average gain problem... though at this point it's only showing a -0.5dB
average gain or so, and impedance and gain seem constant with
segmentation changes, so it's probably not so bad.


What average gain did you expect? In case you had in mind that average
gain would be a big positive number, an antenna doesn't create power,
average gain (ie gain averaged over a sphere) MUST be less than 0dB if
it has ANY loss, mustn't it?

Owen
--

Owen Duffy December 8th 06 05:16 AM

Big Wheel plans
 
On 7 Dec 2006 20:27:37 -0800, "
wrote:

Actually, maybe it doesn't have gain compared to a halo... I'm not
really sure... I have an inconclusive 6m Big Wheel EZNEC model with an
average gain problem... though at this point it's only showing a -0.5dB
average gain or so, and impedance and gain seem constant with
segmentation changes, so it's probably not so bad.

I made it back when I was considering building one and modified it a
little bit to make the avg. gain work out better.

Anyway, if anyone wants to try to get it to work reliably, there's a
model at

http://www.n3ox.net/projects/eznec/6mBigWheel.ez


Dan,

I changed your segmentation, W1=1, W8-W43=1, I get average
gain=0.05dB.

Are you sure that W1 should be 15"? That and the spacing of each pair
of conductors out the the ring gaps are going have a large influence
on feedpoint Z. Did you scale this from another frequency?

Owen

--

John Doe December 8th 06 05:35 AM

Big Wheel plans
 
try these sites:

http://home.tiscalinet.de/wimodata/wheel.pdf

http://www.hb9cru.ch/UKW/Rundstrahl.htm

http://www.mr-as.de/dg2mas/Homepage%20DG2MAS.html

http://members.fortunecity.com/xe1be...rs-antenna.htm

http://www.kb4oid.org/2mssb.php?PHPS...835bd7f5ba 59

http://www.qsl.net/dl4mea/

http://www.k0nr.com/rwitte/rover.html

"Tom Ring" wrote in message
.. .

I've done a fair bit of googling, and haven't found a decent set of plans
to construct a 2m Big Wheel. I have found the original article from 1961,
but the resolution in the pdf is lousy.

Anyone have a link?

tom
K0TAR




Edward Feustel December 8th 06 11:02 AM

Big Wheel gain
 

"Owen Duffy" wrote in message
...
On 7 Dec 2006 20:27:37 -0800, "
wrote:

Actually, maybe it doesn't have gain compared to a halo... I'm not
really sure... I have an inconclusive 6m Big Wheel EZNEC model with an
average gain problem... though at this point it's only showing a -0.5dB
average gain or so, and impedance and gain seem constant with
segmentation changes, so it's probably not so bad.


What average gain did you expect? In case you had in mind that average
gain would be a big positive number, an antenna doesn't create power,
average gain (ie gain averaged over a sphere) MUST be less than 0dB if
it has ANY loss, mustn't it?

Owen
--


The way to get gain is to stack them (with phasing) in order to put as much
power as
possible into low angle transmission.

I have 4 stacked 2 meter big wheels originally manufactured by Cushcraft.
Best Regards,
Ed, N5EI




All times are GMT +1. The time now is 05:30 AM.

Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
RadioBanter.com