Big dish alignment, what am I doing wrong?

[Ben]

Archived from groups: alt.video.satellite.mpeg-dvb (More info?)

My setup is an 8.5' mesh dish, GI-550i receiver w/Chapparal C/KU band
feedhorn. I can get the C-band birds to come in absolutely perfect on
all points of the dish... east, center, west. However, when I try to
pull in KU band I'm having some problems, especially on SBS-6. The KU
birds to the west come in good but could be better. I can make
adjustments to the dish and get SBS-6 to come in near perfect, and my
eastern/center C band birds come in fine, but the far west birds are
just about gone.

My assumption is that with C-band perfectly tuned as it was the KU
birds should be pretty close with perhaps only some minor adjustment
needed. Since I can get all to come in perfectly clean I'm also
assuming my feedhorn and LNB's are fine.

Could it be my north/south axis off a little bit? I've made several
adjustments to the elevation and azimuth and so far haven't found the
right combination to allow me to receive all perfectly. I've read the
following here:
http/www.geo-orbit.org/sizepgs/tuningp4.html
It's slightly technical for me but I think I understand it all. Any
ideas? Thoughts/comments appreciated.

Conversely... if there is anyone in Phoenix that can peak and fine
tune the dish for me I'd be happy to pay for the service. I'm about
to add a MPEG-2 sidecar and want to have it perfectly tuned. Thanks

 

[Guest]

Archived from groups: alt.video.satellite.mpeg-dvb (More info?)

Your arc is a bit off. Make a map of what comes in good and what doesnt and
you can usually tell by which side of the arc has more accessible tp's it's
the opposite way the dish axis needs to go.

I have moved my 8' uniden from one house to another over the years and have
had to adjust the axis a few times due to overzealous lawn mower riding and
a few hurricanes but I dont think you have that problem there.

Lastly I would say, use some chalk to mark the pole before making any
adjustments as it can get frustrating after a few hours of correcting
corrections.

TM
"Ben" <xenon69@softhome.net> wrote in message
news:ercga0prf0pbrsfe8bq69gkd43iurp7k15@4ax.com...
> My setup is an 8.5' mesh dish, GI-550i receiver w/Chapparal C/KU band
> feedhorn. I can get the C-band birds to come in absolutely perfect on
> all points of the dish... east, center, west. However, when I try to
> pull in KU band I'm having some problems, especially on SBS-6. The KU
> birds to the west come in good but could be better. I can make
> adjustments to the dish and get SBS-6 to come in near perfect, and my
> eastern/center C band birds come in fine, but the far west birds are
> just about gone.
>
> My assumption is that with C-band perfectly tuned as it was the KU
> birds should be pretty close with perhaps only some minor adjustment
> needed. Since I can get all to come in perfectly clean I'm also
> assuming my feedhorn and LNB's are fine.
>
> Could it be my north/south axis off a little bit? I've made several
> adjustments to the elevation and azimuth and so far haven't found the
> right combination to allow me to receive all perfectly. I've read the
> following here:
> http/www.geo-orbit.org/sizepgs/tuningp4.html
> It's slightly technical for me but I think I understand it all. Any
> ideas? Thoughts/comments appreciated.
>
> Conversely... if there is anyone in Phoenix that can peak and fine
> tune the dish for me I'd be happy to pay for the service. I'm about
> to add a MPEG-2 sidecar and want to have it perfectly tuned. Thanks

 

[Guest]

Archived from groups: alt.video.satellite.mpeg-dvb (More info?)

You are not correctly aligning your antenna in the arc. First lower
the antenna to the lowest westerly C band satellite viewable. Loosen the
bolts on the antenna mast mount. Watching preferably a tv picture at the
antenna, manually move the antenna slightly back and forth until the best
signal is obtained. Tighten the antenna mount bolts. Raise the antenna
to the highest C band satellite viewable. In Virginia, this is AMC 6, TP
24, although most of the highest C band reception is AMC 9, TP 9, NASA.
Using the threaded rod elevation adjustments, slightly raise or lower
until the best picture is obtained. Then lower the antenna again to the
lowest satellite. Loosen the mount bolts and adjust for best picture.
Tighten the bolts and raise the antenna to the highest viewable C band
satellite. Again, adjust the threaded rod(s) until the best picture is
obtained. Keep doing this until you can tell no difference in the
adjustments. If possible you should try to use AMC7 and AMC6 or AMC9 for
these adjustments. This information assumes that your antenna declination
offset is correctly set for your latitude/longitude.

After these adjustments move the antenna to AMC6. Select SBS6 Ku
band. SLOWLY manually move the motorized antenna in small increments
toward SBS6 stopping frequently to manually tune the receiver channels.
When a video signal is acquired, then peak on that signal.
Most of SBS transmissions are occasional use and sometimes there is no
analog video. Be careful as you may tune across AMC which is slightly
west of SBS6. Conversely tuning for AMC5 go to AMC9, C band. Select AMC5
and manually move the antenna in small increments to the east. Tuning
SBS6 and AMC5 are often difficult but doable. Remember Ku band signals
are less forgiving in tuning errors than C band
signals. Remember the above information is related to an east coast
location. You may have to make appropriate adjustments for a western
location as to the actual highest lowest satellites to tune but the basic
guidance is correct.

Ben wrote:

> My setup is an 8.5' mesh dish, GI-550i receiver w/Chapparal C/KU band
> feedhorn. I can get the C-band birds to come in absolutely perfect on
> all points of the dish... east, center, west. However, when I try to
> pull in KU band I'm having some problems, especially on SBS-6. The KU
> birds to the west come in good but could be better. I can make
> adjustments to the dish and get SBS-6 to come in near perfect, and my
> eastern/center C band birds come in fine, but the far west birds are
> just about gone.
>
> My assumption is that with C-band perfectly tuned as it was the KU
> birds should be pretty close with perhaps only some minor adjustment
> needed. Since I can get all to come in perfectly clean I'm also
> assuming my feedhorn and LNB's are fine.
>
> Could it be my north/south axis off a little bit? I've made several
> adjustments to the elevation and azimuth and so far haven't found the
> right combination to allow me to receive all perfectly. I've read the
> following here:
> http/www.geo-orbit.org/sizepgs/tuningp4.html
> It's slightly technical for me but I think I understand it all. Any
> ideas? Thoughts/comments appreciated.
>
> Conversely... if there is anyone in Phoenix that can peak and fine
> tune the dish for me I'd be happy to pay for the service. I'm about
> to add a MPEG-2 sidecar and want to have it perfectly tuned. Thanks

 

[Guest]

Archived from groups: alt.video.satellite.mpeg-dvb (More info?)

John,did I miss something? How come you did not tell him to align to true
south and the nearest sat by it and then go east or west? I do this all the
time and it works flawlessly,for the whole arc.
"john wilson" <jwilson9@erols.com> wrote in message
news:40DDD740.C8FEC4A4@erols.com...
> You are not correctly aligning your antenna in the arc. First lower
> the antenna to the lowest westerly C band satellite viewable. Loosen the
> bolts on the antenna mast mount. Watching preferably a tv picture at the
> antenna, manually move the antenna slightly back and forth until the best
> signal is obtained. Tighten the antenna mount bolts. Raise the antenna
> to the highest C band satellite viewable. In Virginia, this is AMC 6, TP
> 24, although most of the highest C band reception is AMC 9, TP 9, NASA.
> Using the threaded rod elevation adjustments, slightly raise or lower
> until the best picture is obtained. Then lower the antenna again to the
> lowest satellite. Loosen the mount bolts and adjust for best picture.
> Tighten the bolts and raise the antenna to the highest viewable C band
> satellite. Again, adjust the threaded rod(s) until the best picture is
> obtained. Keep doing this until you can tell no difference in the
> adjustments. If possible you should try to use AMC7 and AMC6 or AMC9 for
> these adjustments. This information assumes that your antenna declination
> offset is correctly set for your latitude/longitude.
>
> After these adjustments move the antenna to AMC6. Select SBS6 Ku
> band. SLOWLY manually move the motorized antenna in small increments
> toward SBS6 stopping frequently to manually tune the receiver channels.
> When a video signal is acquired, then peak on that signal.
> Most of SBS transmissions are occasional use and sometimes there is no
> analog video. Be careful as you may tune across AMC which is slightly
> west of SBS6. Conversely tuning for AMC5 go to AMC9, C band. Select AMC5
> and manually move the antenna in small increments to the east. Tuning
> SBS6 and AMC5 are often difficult but doable. Remember Ku band signals
> are less forgiving in tuning errors than C band
> signals. Remember the above information is related to an east coast
> location. You may have to make appropriate adjustments for a western
> location as to the actual highest lowest satellites to tune but the basic
> guidance is correct.
>
> Ben wrote:
>
> > My setup is an 8.5' mesh dish, GI-550i receiver w/Chapparal C/KU band
> > feedhorn. I can get the C-band birds to come in absolutely perfect on
> > all points of the dish... east, center, west. However, when I try to
> > pull in KU band I'm having some problems, especially on SBS-6. The KU
> > birds to the west come in good but could be better. I can make
> > adjustments to the dish and get SBS-6 to come in near perfect, and my
> > eastern/center C band birds come in fine, but the far west birds are
> > just about gone.
> >
> > My assumption is that with C-band perfectly tuned as it was the KU
> > birds should be pretty close with perhaps only some minor adjustment
> > needed. Since I can get all to come in perfectly clean I'm also
> > assuming my feedhorn and LNB's are fine.
> >
> > Could it be my north/south axis off a little bit? I've made several
> > adjustments to the elevation and azimuth and so far haven't found the
> > right combination to allow me to receive all perfectly. I've read the
> > following here:
> > http/www.geo-orbit.org/sizepgs/tuningp4.html
> > It's slightly technical for me but I think I understand it all. Any
> > ideas? Thoughts/comments appreciated.
> >
> > Conversely... if there is anyone in Phoenix that can peak and fine
> > tune the dish for me I'd be happy to pay for the service. I'm about
> > to add a MPEG-2 sidecar and want to have it perfectly tuned. Thanks
>