does any one have any good moonraker 4 antenna modifcations and does
swr stay down
or web sites will help.

thanks "Tiny"

Hello Tiny:

The Moonraker 4 is a great beam antenna. It was designed around
inexpensive parts, but was very well designed and operated very well.
Having good gain and great rejection.

There are mods out there that install more reflector wires on the quad
reflector. But this will only degrade the Moonraker 4 performance big
time. This being proven with many experiences, and seeing the beams
pattern be distorted from Eznec, a antenna molding program.

The best thing that you can do is use good coax like the LMR-400 and
install the Moonraker 4 on a tower, getting the antenna as high as
possible, with a good rotor, like a HY-Gain 4 or Tailtwister Rotor.

The problem mostly seen with the Moonraker 4 and 6, and PDLII beam
antennas is the use of the Cast Aluminum Hubs that attach the elements
to the boom. Four elements are attached to the Boom using these cheaply
manufactured Cast Aluminum Hubs. After 30 years plus in service these
Cast Aluminum Hubs crack then break after being removed and then
reinstalled again. The best advice is to try to not disturb them.

As the Cast Aluminum Hub is tightened down to compress against the boom
is when the crack and breakage will happen. Even new hubs crack and
break, as I have seen this many times. But when the manufacture was
around supplying replacement hubs there wasn't much of a problem. But
now the manufacture is long gone, these old used hubs have been sold on
E-Bay for 50 dollars for a pair of old unknown condition hubs.

I have had new design hubs made from 6061 T6 Billet Aluminum, but there
not cheap.

I am now rebuilding a Moonraker 6 beam antenna. The Boom has been
replaced with a larger stronger 2 inch diameter Boom, and the boom to
mast Mounting Plate has been replaced and upgraded. The Hubs have been
replaced with the new billet hubs, the over designed truss assembly has
been replaced with a simpler one. The Gamma Matches have been replaced
with a center feed driven element, Hairpin Match, and Balun. The
original elements are the only thing being used from the original antenna.

Photos will come out shortly.

Jay in the Mojave


TINY wrote:

does any one have any good moonraker 4 antenna modifcations and does
swr stay down
or web sites will help.

thanks "Tiny"

On Fri, 02 Dec 2005 06:49:12 -0800, Jay in the Mojave
wrote:

Hello Tiny:

The Moonraker 4 is a great beam antenna. It was designed around
inexpensive parts, but was very well designed and operated very well.
Having good gain and great rejection.

There are mods out there that install more reflector wires on the quad
reflector. But this will only degrade the Moonraker 4 performance big
time. This being proven with many experiences, and seeing the beams
pattern be distorted from Eznec, a antenna molding program.

The best thing that you can do is use good coax like the LMR-400 and
install the Moonraker 4 on a tower, getting the antenna as high as
possible, with a good rotor, like a HY-Gain 4 or Tailtwister Rotor.

The problem mostly seen with the Moonraker 4 and 6, and PDLII beam
antennas is the use of the Cast Aluminum Hubs that attach the elements
to the boom. Four elements are attached to the Boom using these cheaply
manufactured Cast Aluminum Hubs. After 30 years plus in service these
Cast Aluminum Hubs crack then break after being removed and then
reinstalled again. The best advice is to try to not disturb them.

As the Cast Aluminum Hub is tightened down to compress against the boom
is when the crack and breakage will happen. Even new hubs crack and
break, as I have seen this many times. But when the manufacture was
around supplying replacement hubs there wasn't much of a problem. But
now the manufacture is long gone, these old used hubs have been sold on
E-Bay for 50 dollars for a pair of old unknown condition hubs.

I have had new design hubs made from 6061 T6 Billet Aluminum, but there
not cheap.

I am now rebuilding a Moonraker 6 beam antenna. The Boom has been
replaced with a larger stronger 2 inch diameter Boom, and the boom to
mast Mounting Plate has been replaced and upgraded. The Hubs have been
replaced with the new billet hubs, the over designed truss assembly has
been replaced with a simpler one. The Gamma Matches have been replaced
with a center feed driven element, Hairpin Match, and Balun. The
original elements are the only thing being used from the original antenna.

Photos will come out shortly.

Jay in the Mojave


TINY wrote:

does any one have any good moonraker 4 antenna modifcations and does
swr stay down
or web sites will help.

thanks "Tiny"


what performs better, your i10k or a beam antenna? (i know your i10k
will withstand the stronger winds over most anything out there at the
moment.)

thanks!

Buther Boy

--
The art of love... is largely the art of persistence. - Albert Ellis
~

Jay in the Mojave wrote:

Hello Tiny:

The Moonraker 4 is a great beam antenna. It was designed around
inexpensive parts, but was very well designed and operated very well.
Having good gain and great rejection.

There are mods out there that install more reflector wires on the quad
reflector. But this will only degrade the Moonraker 4 performance big
time. This being proven with many experiences, and seeing the beams
pattern be distorted from Eznec, a antenna molding program.

The best thing that you can do is use good coax like the LMR-400 and
install the Moonraker 4 on a tower, getting the antenna as high as
possible, with a good rotor, like a HY-Gain 4 or Tailtwister Rotor.

The problem mostly seen with the Moonraker 4 and 6, and PDLII beam
antennas is the use of the Cast Aluminum Hubs that attach the elements
to the boom. Four elements are attached to the Boom using these cheaply
manufactured Cast Aluminum Hubs. After 30 years plus in service these
Cast Aluminum Hubs crack then break after being removed and then
reinstalled again. The best advice is to try to not disturb them.

As the Cast Aluminum Hub is tightened down to compress against the boom
is when the crack and breakage will happen. Even new hubs crack and
break, as I have seen this many times. But when the manufacture was
around supplying replacement hubs there wasn't much of a problem. But
now the manufacture is long gone, these old used hubs have been sold on
E-Bay for 50 dollars for a pair of old unknown condition hubs.

I have had new design hubs made from 6061 T6 Billet Aluminum, but there
not cheap.

I am now rebuilding a Moonraker 6 beam antenna. The Boom has been
replaced with a larger stronger 2 inch diameter Boom, and the boom to
mast Mounting Plate has been replaced and upgraded. The Hubs have been
replaced with the new billet hubs, the over designed truss assembly has
been replaced with a simpler one. The Gamma Matches have been replaced
with a center feed driven element, Hairpin Match, and Balun. The
original elements are the only thing being used from the original antenna.

Photos will come out shortly.

Jay in the Mojave


TINY wrote:

does any one have any good moonraker 4 antenna modifcations and does
swr stay down
or web sites will help.
thanks "Tiny"

Hey Jay, agreed the hubs of the PDLII are fragile. IMHO the tuning of
those ants is another drawback though when done correctly they operate
very well.

Hello jim:

Yeah I had a problem tuning them also, no matter where I placed the
Gamma Match Rod adjustments, it seemed to have a mind of its own. The
Gamma Matches biting me again.

Thats why the Gamma Matches will be lost for the Moonraker 6 rebuild.

But after all that, yes it is a very impressive beam a antenna.

Jay in the Mojave

jim wrote:
Hey Jay, agreed the hubs of the PDLII are fragile. IMHO the tuning of
those ants is another drawback though when done correctly they operate
very well.

Hello Buther Boy:

The beam antenna should out perform the Interceptor 10K 5/8 wavelength
ground plane antenna. If the beam is designed and built right.

But not all beams are. Money is well spent in the proper feeding and
matching of any antenna. Which is not always the mass produced,
manufactured low cost way.

Having a beam antenna with a low cost and lossy feed system, is like
Nascar with a one barrel carburetor on it. It will look good and make
some noise but get easily beat.

Jay in the Mojave




Buther Boy wrote:
what performs better, your i10k or a beam antenna? (i know your i10k
will withstand the stronger winds over most anything out there at the
moment.)

thanks!

Buther Boy

--
The art of love... is largely the art of persistence. - Albert Ellis
~

On Sat, 03 Dec 2005 06:34:07 -0800, Jay in the Mojave
wrote:

Hello Buther Boy:

The beam antenna should out perform the Interceptor 10K 5/8 wavelength
ground plane antenna. If the beam is designed and built right.

But not all beams are. Money is well spent in the proper feeding and
matching of any antenna. Which is not always the mass produced,
manufactured low cost way.

Having a beam antenna with a low cost and lossy feed system, is like
Nascar with a one barrel carburetor on it. It will look good and make
some noise but get easily beat.

Jay in the Mojave




Buther Boy wrote:
what performs better, your i10k or a beam antenna? (i know your i10k
will withstand the stronger winds over most anything out there at the
moment.)

thanks!

Buther Boy

--
The art of love... is largely the art of persistence. - Albert Ellis
~

thanks for the info, jay... i will definitely remember that for future
installations. i just hope your business is around in 25 years!!

Buther Boy

--
The art of love... is largely the art of persistence. - Albert Ellis
~

On Sat, 03 Dec 2005 06:34:07 -0800, Jay in the Mojave
wrote:

+But not all beams are. Money is well spent in the proper feeding and
+matching of any antenna. Which is not always the mass produced,
+manufactured low cost way.
+
+Having a beam antenna with a low cost and lossy feed system, is like
+Nascar with a one barrel carburetor on it. It will look good and make
+some noise but get easily beat.
+
+Jay in the Mojave
*****

This is a good one. Best laugh I h ave had in a few days.

thanks
james

ps:

I just love people that slam mass manufactureing. Without it you sure
as heck wouldn't be buying stuff at the prices you do.

james

Gamma Matches are a very excellent means of matching 50 Ohm unbalanced
feed to a balanced feed antenna of lower feed impedance than that of
the feed transmision line.

Most difficulty with gamma matches comes when the feed point is below
1/4 lambda above ground. Ground and other reflections tend to alter
the feed point impedance and makes matching more difficult. Most
difficulty comes due to heigth above ground for the feed point and the
inability of the driven element being adjustable.

Depending on heigth of the feedpoint, the driven element and the gamma
match need itterative adjustments so that an acceptable match is
acheived.

james

On Sat, 03 Dec 2005 06:13:38 -0800, Jay in the Mojave
wrote:

+Hello jim:
+
+Yeah I had a problem tuning them also, no matter where I placed the
+Gamma Match Rod adjustments, it seemed to have a mind of its own. The
+Gamma Matches biting me again.
+
+Thats why the Gamma Matches will be lost for the Moonraker 6 rebuild.
+
+But after all that, yes it is a very impressive beam a antenna.
+
+Jay in the Mojave
+
+jim wrote:
+ Hey Jay, agreed the hubs of the PDLII are fragile. IMHO the tuning of
+ those ants is another drawback though when done correctly they operate
+ very well.

Hello James:

Good luck with the one barrel carburetor.

Jay in the Mojave


james wrote:

On Sat, 03 Dec 2005 06:34:07 -0800, Jay in the Mojave
wrote:


+But not all beams are. Money is well spent in the proper feeding and
+matching of any antenna. Which is not always the mass produced,
+manufactured low cost way.
+
+Having a beam antenna with a low cost and lossy feed system, is like
+Nascar with a one barrel carburetor on it. It will look good and make
+some noise but get easily beat.
+
+Jay in the Mojave

*****

This is a good one. Best laugh I h ave had in a few days.

thanks
james

ps:

I just love people that slam mass manufactureing. Without it you sure
as heck wouldn't be buying stuff at the prices you do.

james